EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: torch on February 24, 2013, 04:25:45 am

Title: $20 LCR ESR Transistor checker project
Post by: torch on February 24, 2013, 04:25:45 am
A few weeks ago I stumbled over this fellow on fleabay:

(http://picturehosting.verhey.org/lcr/lcr.JPG).

What the heck, for $20 it looked like it could be fun, especially for a dilettante like me with a drawer full of oddball small signal mystery transistors. I put it in a project box, added some leads and a switch and hooked up a 9v battery.  Operation is simple: connect the component (leads in any order),  push test. It tells you what it is and the value:

A 1% resistor:

(http://picturehosting.verhey.org/lcr/resistor.jpg)

A capacitor (this one must have real low ESR -- usually there's a value in ohms):

(http://picturehosting.verhey.org/lcr/capacitor.jpg)

A transistor (note that it tells you if it's PNP or NPN and which lead is connected to what, gain and forward voltage):

(http://picturehosting.verhey.org/lcr/transistor.jpg)

How about an inductive load?

(http://picturehosting.verhey.org/lcr/coil.jpg)

FAIL! That's an IGBT, not a capacitor. (To be fair, it's rated 600v/40amps):

(http://picturehosting.verhey.org/lcr/IGBT.jpg)

Partial Fail. This is a power transistor, not a pair of diodes. Oh well, at least I can figure out from that if it's PNP or NPN:

(http:///picturehosting.verhey.org/lcr/power_transistor.jpg)

FAIL again -- Ooops, no it's not. My mistake. That really IS a diode that got mixed in with the SCRs -- look at the number:

(http://picturehosting.verhey.org/lcr/Diode.jpg)

Ok, here's a real SCR (GAC indicates which lead connected to the Gate, Anode and Cathode, respectively):

(http://picturehosting.verhey.org/lcr/SCR.jpg)

But an LM317 threw it for a loop:

(http://picturehosting.verhey.org/lcr/LM317.jpg)

The documentation is non-existent. I accidentally discovered a self-test/calibration mode by connecting all 3 leads to each other and pushing the button. On-screen directions kind of guide you through each numbered step if you scratch your head long enough deciphering them. A 100nF capacitor is required at one point (step 4, IIRC).

Anyway, a cute little gizmo, certainly worth the $20 and it seems reasonably accurate within the scope of it's limitations.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Lightages on February 24, 2013, 04:34:17 am
Could you give a few more capacitors a try to see if it actually can measure ESR. What is the test voltage for capacitors?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Analogtech on February 24, 2013, 05:17:31 am
I remember seeing the exact same thing on eirik Taylors blog on 4hv. It had pretty good documentation and test results on it so you might want to go check that out
Title: Re: $20 LCR ESR Transistor checker project
Post by: Lightages on February 24, 2013, 05:43:10 am
I looked for the review or blog and got nowhere. A link please?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Analogtech on February 24, 2013, 06:09:33 am
http://uzzors2k.4hv.org/index.php?page=lcfmeter (http://uzzors2k.4hv.org/index.php?page=lcfmeter) that's the link to the blog
Title: Re: $20 LCR ESR Transistor checker project
Post by: fmaimon on February 24, 2013, 06:45:24 am
http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester)
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 24, 2013, 07:06:47 am
Could you give a few more capacitors a try to see if it actually can measure ESR. What is the test voltage for capacitors?

What, don't believe me???? <lol>

I am not sure what the test voltage is for capacitors, I looked at the test sequence on a scope and it sends out a lot of little pulses on the leads, and which does what is beyond my ken. However, the highest voltage seems to be about 3.5v or thereabouts near the end of the sequence with a capacitor attached.

And actually, your question is a fair one because there seems to be a cut-off between 1uf and 2uf below which it does not attempt to measure ESR. Here are some photos as proof:
 
Here's a 10uf capacitor:

(http://picturehosting.verhey.org/lcr/01_10uf.jpg)

and here's a 1% 1 ohm resistor:

(http://picturehosting.verhey.org/lcr/02_1_ohm.jpg)

Here they are in series:

(http://picturehosting.verhey.org/lcr/03_esr+resistor.jpg)


I didn't have a 1uf capacitor, so here's two 2.2 in series. No ESR value shown:

(http://picturehosting.verhey.org/lcr/04_1.1uf.jpg)

But a 2.2uf alone is measured for ESR:

(http://picturehosting.verhey.org/lcr/05_2.2uf.jpg)

A 1000uf can has a really low ESR:

(http://picturehosting.verhey.org/lcr/06_1000uf.jpg)

And here's a few random used cardboard electrolytics, for fun:

(http://picturehosting.verhey.org/lcr/07_old_paper1.jpg)

(http://picturehosting.verhey.org/lcr/08_old_paper2.jpg)

(http://picturehosting.verhey.org/lcr/09_old_paper3.jpg)

I had a quick look at that blog link. It may have been the genesis of this one, but it's certainly not the same thing.   







Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 24, 2013, 07:16:34 am
Ok, the first link may not be the same thing, but the second one sure sounds like it. I think. It's in German, but here's google's translation effort:

http://translate.google.ca/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&eotf=1&u=http%3A%2F%2Fwww.mikrocontroller.net%2Farticles%2FAVR-Transistortester (http://translate.google.ca/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&eotf=1&u=http%3A%2F%2Fwww.mikrocontroller.net%2Farticles%2FAVR-Transistortester)
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 24, 2013, 12:30:47 pm
I got one of these too - they are a lot of fun. The component values are usually within 1%. Does a pretty good job correctly identifying transistors, diodes, etc.

I did try a tough test  - a RCA 2N3669 thyristor and it identifier it as a 33 ohm resistor. This is not surprising as there is a built in 33 ohm resistor from gate to cathode. It found the resistor and didn't look any further I guess.

Not sure how good it is as an ERS meter. I am not going to do any proper tests now. If I short two inputs together, I get 0.2 ohms and there is nothing to cancel this out. The best accuracy you could expect is 0.1 ohms even though the software calculates ESR to 2 places.

If I get to fiddle with the software, a feature to force it to test in one mode (resistance, capacitance, inductance, etc) could be good. As a single button tester, it is not bad at all.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 24, 2013, 01:39:47 pm
If I short two inputs together, I get 0.2 ohms and there is nothing to cancel this out. The best accuracy you could expect is 0.1 ohms even though the software calculates ESR to 2 places.

If you short all 3 it will go into the self-calibration mode and then it will read 0 ohms when you short 2 leads together. Just make sure you have a 100nF capacitor handy and follow the prompts or it will eventually read 33pF when you short 1 and 3. Don't Ask Me How I Know This(tm).  :scared:

I went through that damn routine more than once before I figured it out.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 24, 2013, 02:18:43 pm
If you short all 3 it will go into the self-calibration mode and then it will read 0 ohms when you short 2 leads together. Just make sure you have a 100nF capacitor handy and follow the prompts or it will eventually read 33pF when you short 1 and 3. Don't Ask Me How I Know This(tm).  :scared:

I went through that damn routine more than once before I figured it out.
Wow - I just did it (including the 0.1uF 0.5% cap) and it does do the self-calibration test. Who needs metrology labs?

After calibration, a short went down to 0.1 ohms, but to be fair, the wires I was using to short the pins for the calibration were not the best.

Looks like they use a 2V zener in series with 2k2 from a 5V regulator. That will not be very stable. I think the original circuit used a LT reference IC instead. I wonder how it calibrates its voltage reference?

Update: After the calibration, I now get 35P between pins 2 and 3 with nothing connected. I better read up on the calibration.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ecat on February 24, 2013, 02:20:47 pm
Ok, the first link may not be the same thing, but the second one sure sounds like it. I think. It's in German, but here's google's translation effort:

http://translate.google.ca/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&eotf=1&u=http%3A%2F%2Fwww.mikrocontroller.net%2Farticles%2FAVR-Transistortester (http://translate.google.ca/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&eotf=1&u=http%3A%2F%2Fwww.mikrocontroller.net%2Farticles%2FAVR-Transistortester)

That is the original by Markus Frejek.


This is the modified version courtesy of  Karl-Heinz Kübbeler...

http://translate.google.com/translate?hl=en&sl=de&u=http://www.mikrocontroller.net/articles/AVR_Transistortester&prev=/search%3Fq%3Dtransistortester.tar.gz%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26hs%3DILT%26rls%3Dorg.mozilla:en-GB:official&sa=X&ei=PYQpUbfWMenD0QWrn4GQCg&ved=0CFMQ7gEwBA (http://translate.google.com/translate?hl=en&sl=de&u=http://www.mikrocontroller.net/articles/AVR_Transistortester&prev=/search%3Fq%3Dtransistortester.tar.gz%26hl%3Den%26safe%3Doff%26client%3Dfirefox-a%26hs%3DILT%26rls%3Dorg.mozilla:en-GB:official&sa=X&ei=PYQpUbfWMenD0QWrn4GQCg&ved=0CFMQ7gEwBA)

... see Download for a link to the full source + comprehensive documentation.


I built one last week, the fun part was persuading an Arduino to do the job of an AVR programmer :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 24, 2013, 02:55:40 pm
Here is the most recent PDF for the tester, including information about the chinese clones. I have to say it is a really great manual.

You are meant to replace the zener with a decent reference.

In the self calibration, the shorted inputs should be removed during test 4. When this is done, the tester works properly again.

The V2.2 board I got has a JTAG 10 pin ISP port and a ATMEGA168 (with the part number rubbed off) and apparently it works fine if updated to the latest software. Mine came with software version 105k. Karl Heinz's's latest version is 106k. I will give it a go sometime.

There are some additions that can be done. One is a circuit to generate up to 30VDC for measuring zener breakdown voltage.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ecat on February 24, 2013, 04:50:17 pm
Just tested the accuracy of my home made version.

A 0.01% 5k resistor reads 5066, so about 1.3% which is good enough for a quick test. I matched the 680r and 470k resistors to the third digit, maybe better matching would help.

Still, a nice little project if you have a way to program up a Mega328. I've attached the Eagle 6.3.0 files for my single sided diy version of Karl-Heinz Kubbeler V1.06k if anyone is interested. I do not claim any competence with schematics or board layout so use at your own risk :)

Board Notes:
The two jumper wires are optional.

You probably don't need the 5V jumper wire to the program header. Even if you program the 328 in circuit just make sure the board is powered by keeping SW1 closed. You should always try to avoid supplying power to a circuit from both the board and your programming device, this is not be a good thing as you should never let the beams cross ;).

The Reset jumper wire is needed if you program in circuit. If you program the 328 out of circuit you can ignore this jumper and the 6 pin header.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 24, 2013, 11:44:43 pm
Here is the most recent PDF for the tester, including information about the chinese clones. I have to say it is a really great manual.

That PDF you found  is great! I have only skimmed it thus far, but it does cover a lot of territory.  I too have the "2.2" version, and I note that he describes a potential problem with zeroing the resistance test if the 2.2 is updated to the latest software (1.06):

Quote
"The printed circuit board track from the ATmega168 to the test port is very thin, so that a resistance of 100m
 could be measured for one path. This will be the reason for measuring a resistance of 0:3  for two direct connected pins. The ESR measuring can usually consider this by zero compensation. The current version of software does not respect this off set for measuring of resistors with low resistance."

I also found the explanation of why I had an ESR of "0?" in that first capacitor:
Quote
"with the AUTOSCALE ADC option. The zero o set for the ESR measurement will be preset with the option ESR ZERO in the Make le. This zero o set, which is set too high in normal case, will be preset in EEprom by the software. With every selftest the ESR zero o set will be reset to this initial value. After every ESR measurement the result will be checked for negative value (output of "ESR=0?"). In this case the zero o set will be reduced to get a zero result for next ESR measurement. With this methode the zero o set can be adjusted with a electrolytical capacitor with high capacity value and low ESR value. This learned ESR zero o set remains active after power o , but the adjust procedure to get the zero o set of ESR measurement must be done after every selftest and in this case you should always repeat the measurement some times."

I won't quote the entire section on how the ESR is done. However, the doc confirms that the device will only determine ESR for caps over 2uF. I suspect this is because the frequency is only 680Hz instead of the more traditional 100MHz. Apparently it repeats the test 128 times and sums the values to derive the final answer, but he cautions that the ESR test is not to be considered accurate compared to a dedicated ESR meter.

It is interesting to note the effort that has gone into adjusting the capacitance measurement accuracy. Again, I was just skimming, but he seems to have done some extensive testing of the raw capabilities compared to an LCR meter and a multimeter, (looks like the native ATmega results fell between the two) then formulated some correction factors to bring the results closer in line to the LCR results.

A lot of thought and effort went into this little thing -- on his part, anyway. The Chinese just copied and mass produced.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 25, 2013, 12:29:06 am
This transistor tester is a masterclass in making use of the internal hardware of an atmega. The internal analog switch resistances are measured, the internal comparitor offset is measured. The hardware is used in many different modes to achieve a result. Brilliant. It is all much more sophisticated then I was expecting.

By using 3 ports per test pin each along with two precision resistors, the effective total of test hardware per pin is 9 resistors, 3 three position single pole switches (to GND, VCC and open circuit), three comparitors and one ADC. The ADC is switched between different references

The thing you realize is that the quality of the hardware embedded in the atmega IC is very good.

When you do the self calibrate, it outputs the calibration factors that also indicate something about the hardware.

For example test 7 checks the ratios of the 470K and 680 ohm resistors to the expected. They were meant to be 0.1% resistors, so the match should be good. In my tester, the errors were 1 mv for each of the three resistor pairs. It does look like the Chinese did actually use 0.1% SMD resistors. I know my 680 ohm resistors match within 0.1%, but I cannot measure the 470K resistors accurately in circuit.

I think they would love to build this with a chip with a better A/D, but a 5V chip is required - the lower voltage chips don't work as well for semiconductor testing.

I love it when someone wrings every bit of performance out of a piece of hardware, and that is exactly what is done in this transistor tester project. They admit somethings are not optimal yet, and there are some errors they cannot yet explain, but they are continually improving the design.

A very good project.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on February 25, 2013, 12:38:10 am
Well, yes, this little tester is a fine project with lots of effort put into it!

This is the current discussion thread of this project in German, with a vivid presence of the author of that port of the project, Karl-Heinz Kübbeler:
http://www.mikrocontroller.net/topic/248078#2950824 (http://www.mikrocontroller.net/topic/248078#2950824)

Unfortunately, http://translate.google.com/ (http://translate.google.com/) cannot handle such long threads but it is more than sufficient to translate individual posts.

This is also the project's source code archive:
http://www.mikrocontroller.net/svnbrowser/transistortester/ (http://www.mikrocontroller.net/svnbrowser/transistortester/)

If I manage to find some time to spare I will rewrite this project in assembly, in order to speed things up a little bit by avoiding the C compiler bloating. If I am not mistaken, the current version of the code (v1.06k) does not take into consideration the hardware ADC offset by initially measuring it and subtracting it from every ADC result; this would certainly improve the overall tester accuracy.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 25, 2013, 01:12:59 am
If I am not mistaken, the current version of the code (v1.06k) does not take into consideration the hardware ADC offset by initially measuring it and subtracting it from every ADC result; this would certainly improve the overall tester accuracy.

You have obviously got further then me. I have only spent a couple of hours with the manual. I particularly want to work through some of the measurements like the ESR in detail.

I would have though that the calibration factors that they measure and store would cancel out the ADC offsets. I cannot see any reason to correct every ADC result, when you can correct once at the end instead. I am definitely not discounting your point - I haven't looked at the calculations to see what effect errors at the start would have on the final result. It could be better to correct every reading.

I just looked at the data sheet and it looks like the total error in the ADC, including offset and non-linearity is about 0.2% with a 200KHz clock rising to about 0.5% with a 1MHz clock.

A complete correction of the ADC linearity and errors using our PWM voltage source would be interesting. That would need some great assembler coding for speed. It would probably at best double the accuracy but the hardware cost would be a few caps, resistors and another test connection to output the PWM. And time.

Richard.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on February 25, 2013, 01:34:53 am
Ah no, Richard, I have not really studied the project in that depth of detail! I've just had a quick look at its source code and I noticed that omission.

Now, on the self canceling out of the ADC errors, yes, theoretically it would work; but I cannot see any reason why not to subtract from the ADC results any measured possible offset, which varies from -2 .. +2 LSB according to the data sheets. Especially, when those possible errors accumulate by oversampling. Of course, summing readings that are taken both ways (positive and negative) would cancel out those unwanted accumulated quantities. My point is that it would not hurt to try this out and compare the results.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on February 25, 2013, 02:34:48 am
Damn, both of you Richard and George have made me to put this thread in one of my top watch list.  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 25, 2013, 05:57:01 am
Yeah, it is starting to look like this thread is taking on a life of it's own, doesn't it?   ;D

I don't seem to have any caps above 1000uf available, so I started stringing them together. The ESR value is definitely self-calibrating depending upon the highest capacitance it has measured. Adding each successive capacitor, the ESR is shown as 0? on the first test or two, then settles around .01 to .03 ohms. Testing a control cap, the indicated ESR climbs slightly each time the baseline is set. I got up to ~7200uF and the control went from 0.01ohms to 0.12ohms. Actually, there is about .02 ohms variability there -- pushing the test button repeatedly without disturbing the leads at all will result in successive readings between 0.11 and 0.13 ohms.

So don't take the ESR figure as gospel. It's really a comparison with the ESR of the largest cap it has previously encountered (since the last self-test/calibration) considered as 0.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 25, 2013, 07:45:35 am
If I manage to find some time to spare I will rewrite this project in assembly, in order to speed things up a little bit by avoiding the C compiler bloating. If I am not mistaken, the current version of the code (v1.06k) does not take into consideration the hardware ADC offset by initially measuring it and subtracting it from every ADC result; this would certainly improve the overall tester accuracy.

Actually, speed is no concern since a lot of the time the firmware has to wait, e.g. for the ADC. There's also no gain from changing the crystal from 8 to 16 MHz; a faster ADC would help. A zero offset of the ADC was already discussed and the idea was dropped. A changing offset (=noise) helps with the oversampling.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on February 25, 2013, 09:17:45 am
Damn, both of you Richard and George have made me to put this thread in one of my top watch list.  :-+

+1  I am with BravoV, nice job with documenting guys :)  And thanks for the measurements Torch.
I ordered one a week ago, might build a case for it too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 25, 2013, 02:56:30 pm
+1  I am with BravoV, nice job with documenting guys :)  And thanks for the measurements Torch.
I ordered one a week ago, might build a case for it too.

Ok, that makes me think:

I'm involved with mentoring the local high school's robotic's club (don't worry, not the electronics, I help out with machining the mechanical bits!  ;) ). Anyway, they are looking for some fundraising ideas. They have a PVC 3d printer in the shop class. Would there be any interest in having cases made for these? Maybe a kit with the leads, shielded bannana plugs and clips included? And a separate battery compartment. I would definitely want a separate battery compartment. What other features would you look for and how much would something like that be worth to you?
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on February 25, 2013, 03:19:21 pm
Yeah, it is starting to look like this thread is taking on a life of it's own, doesn't it?   ;D
This two kind gentlemen are well known to generate a really excellent discussion when they're "in-sync"  ;) with each other at the same topic similar at this one here.

Here an example at the topic on generating an adjustable + high resolution voltage reference using cheapo components -> Amspire's thread : General Purpose Power Supply Design (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/). Imo it is one of the best among finest threads in this forum, just take a cup of coffee and read it your self, its a long thread.  :P  Too bad that project is on hold.  :'(

Ok, enough OOT, I bet you've got my point. ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on February 25, 2013, 05:04:09 pm
[...]
Too bad that project is on hold.  :'(
Any decent designer ought to have a handful of projects on hold! :P
I mean that, giving birth to an idea does not necessarily mean that spiritual inspiration can be switched ON and OFF on demand; there will always be lots of other variables in the way...
Thank you for your kind words!


Actually, speed is no concern since a lot of the time the firmware has to wait, e.g. for the ADC. There's also no gain from changing the crystal from 8 to 16 MHz; a faster ADC would help. A zero offset of the ADC was already discussed and the idea was dropped. A changing offset (=noise) helps with the oversampling.
Thank you for the information.

If I am not mistaken, I can see that you are Markus (http://www.eevblog.com/forum/testgear/$20-esr-lcr-transistor-npn-pnp-mosfet-meter/msg188659/#msg188659), the author of the current -m versions along with Karl-Heinz's -k ones! Firstly, let me congratulate you both for your efforts.

I am familiar with oversampling and the decimation/averaging method of achieving higher resolutions as well as with the (random) noise injection method of a few LSBs into the under test signal, in order to assist oversampling. I also agree in that the standard 8-bit AVR ADC might be insufficient for any faster or any better accuracy results than those already achieved, since its non-linearity and gain errors put a ceiling to the final acquisition product maximum resolution accuracy.

Now, it is a fact that even 1 LSB offset error narrows down the usable range of the 1024 discrete steps of the 10-bit ADC available output by one unit, affecting the final product value by introducing a minor scaling error. Is this the reason why the ADC results offset corrections were overruled? Because, during the auto-calibration procedure, the offset error can be measured, compensated, and it can be used for the calculation of the usable ADC range; and all these additional ADC parameters can be also stored in EEPROM along with the other device parameters.


A complete correction of the ADC linearity and errors using our PWM voltage source would be interesting. That would need some great assembler coding for speed. It would probably at best double the accuracy but the hardware cost would be a few caps, resistors and another test connection to output the PWM. And time.
I really like your idea, Richard!

Changing dynamically the voltage reference by the use of the available PWM hardware might breathe new life into this already impressive project, by expanding dramatically the device's dynamic range. Of course, any fancy hardware changes will be a problem to the existing standard devices, which will not be able to make use of any possible new features without any PCB/hardware (heavy) modifications.

Other than that, and based on the latest Component Tester schematics, any of the PC5:PC3 spare I/O lines could be exchanged with PB1 (or PB2) in order to take advantage of the OC1A (or the OC1B) 16-bit PWM outputs (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/msg103985/#msg103985) (with a sub-millivolt resolution!); another ADC line of the spare ones (PC6:PC3) is needed to be driven by the configurable PWM voltage reference generated (through an additional RC low-pass filter). The external crystal should not be dropped (in order to utilise the PB7:PB6 I/O lines) because it would impair the time-based measurements accuracy. The only drawback I can see is the additional time needed (in the order of a couple of hundreds of milliseconds) for the PWM output RC filter to reach its final output before it can be used as a stable voltage reference. As a bonus, the very low level ripple induced by the PWM stage will assist oversampling.

Unfortunately, the m168/m328 ADC does not support differential channels input, nor the relatively high impedance PWM stage RC filter output can drive directly the 32 Kohm AREF input line without any external buffering; but this error can be measured and compensated if this configuration is chosen to be used.


In a few words, the improvements potential of this project seems to be promising! I guess that I will have to build a device (or order a chineese copycat) for any further experimentation...


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on February 25, 2013, 07:39:32 pm
I would prefer an SPI/I2C driven, precision DAC. Don't know if the pin count allows it. Maybe shared with the LCD.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on February 25, 2013, 07:51:37 pm
I would prefer an SPI/I2C driven, precision DAC. Don't know if the pin count allows it. Maybe shared with the LCD.

Alexander.

I believe they're opening up the challenge not to touch the hardware design, all will be done purely at software to improve this circuit.
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on February 25, 2013, 07:58:22 pm
They will have toy use capacitors and resistor for the PWM filter. Just joking!

A DAC could be just bodged to the main pcb. I might give it a try my self.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 25, 2013, 10:42:05 pm
If I am not mistaken, I can see that you are Markus (http://www.eevblog.com/forum/testgear/$20-esr-lcr-transistor-npn-pnp-mosfet-meter/msg188659/#msg188659), the author of the current -m versions along with Karl-Heinz's -k ones! Firstly, let me congratulate you both for your efforts.

Thanks! You're welcome! I forwarded the URL of this thread to Karl-Heinz, so he can enjoy this too ;-)

Quote
Now, it is a fact that even 1 LSB offset error narrows down the usable range of the 1024 discrete steps of the 10-bit ADC available output by one unit, affecting the final product value by introducing a minor scaling error. Is this the reason why the ADC results offset corrections were overruled? Because, during the auto-calibration procedure, the offset error can be measured, compensated, and it can be used for the calculation of the usable ADC range; and all these additional ADC parameters can be also stored in EEPROM along with the other device parameters.

Karl-Heinz tested a lot of ATmegas (same and different models) and none showed any large offset for the internal 10 bit ADC. Surely, the offset has an impact on the result but it's quite low based on the findings. The ADC measurements are done in a tiered way. The first measurement uses 5V as reference voltage and if the result is below the internal bandgap reference (about 1.1V for the more powerful ATmegas) the measurement is repeated using the bandgap reference. The accuracy of that bandgap reference (about 10%) causes much more trouble than a low ADC offset. Of course the voltage of the bandgap reference is measured, but using 5V as reference for that doesn't give a high accuracy either. Karl-Heinz' firmware version supports an optional external voltage reference of 2.5V to improve the accuracy.

Quote
Changing dynamically the voltage reference by the use of the available PWM hardware might breathe new life into this already impressive project, by expanding dramatically the device's dynamic range. Of course, any fancy hardware changes will be a problem to the existing standard devices, which will not be able to make use of any possible new features without any PCB/hardware (heavy) modifications.

One of the projects main goals is to support the classic transistor tester design because a lot of people built that. There's more value in improving and extending the firmware than in upgrading the hardware every few months for a OSHW project. BTW, there are two hardware extensions, which are compatible with the current design. One is a relay to discharge caps with voltages above 5V and the other is a high voltage addon for zehner diodes. AFAIK we'll keep it that way until we hit the nothing-can-be-improved-anymore mark. When that happens there might be a Tester+. I'll note your ideas and suggestions ;-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Telstar on February 26, 2013, 12:27:59 am
very nice project!
At first i thought it was a clone of the Peak Electronic testers but then I think it's something different and with more functions than any of their devices taken alone.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on February 26, 2013, 12:32:02 am
Changing dynamically the voltage reference by the use of the available PWM hardware might breathe new life into this already impressive project, by expanding dramatically the device's dynamic range. Of course, any fancy hardware changes will be a problem to the existing standard devices, which will not be able to make use of any possible new features without any PCB/hardware (heavy) modifications.

One of the projects main goals is to support the classic transistor tester design because a lot of people built that. There's more value in improving and extending the firmware than in upgrading the hardware every few months for a OSHW project. BTW, there are two hardware extensions, which are compatible with the current design. One is a relay to discharge caps with voltages above 5V and the other is a high voltage addon for zehner diodes. AFAIK we'll keep it that way until we hit the nothing-can-be-improved-anymore mark. When that happens there might be a Tester+. I'll note your ideas and suggestions ;-)
Markus, great to see you in this forum. I just find the efforts of you and Karl-Heinz inspiring. You have used the Atmega processors in ways I never even considered, and it is exciting.

I do understand that your project is all about very simple hardware, and making improvements through firmware, but you may be interested in the work George (A Hellene) and I did on the Atmega PWM as a voltage divider/reference.

To summarize, what we found was that you can get extremely impressive precision and resolution using the 8 bit PWM - the performance was a long way superior to the 16 bit PWM. This means that the processor can output two precision voltages or divider ratios at resolutions up to 24 bit with less then a second settling time with a few lines of code. Hardware is as little as three 5% resistors and three multilayer ceramic capacitors per reference output.

One of the things I found was that for precision circuits, use the full swing clock for a ceramic resonator, not the low power one. The full swing clock is noise insensitive and the jitter appears to be less then 1nS even on a breadboard. The lower power clock has more of jitter and it is very sensitive to modulation from nearby electrical noise - particularly LCD displays. Going from a low power clock to the high power clock probably improved the PWM linearity by a factor of over 10 on a breadboard test. I didn't test to see if a crystal instead of a ceramic resonator has the same issues, but there may well be some degradation.

If you are interested, take a look at this post first. When I did this test, I was going to be happy if I achieved better then 1% accuracy:

http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/150/ (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/150/)

If that gets you interested, then the first relevant post is here:

http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/msg99807/#msg99807 (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/msg99807/#msg99807)

It is a long thread unfortunately.

The idea started from the need for a very high resolution and very cheap reference source for voltage and current for a low cost power supply. I wanted to be able to monotonically adjust voltage down to about 10uV steps so I could use the supply for tasks like providing the DC voltage input to a Fluke 540B RMS calibrator. For that an adjustable DC source is needed that is stable and can be adjusted down to the 0.001% level resolution. Accuracy wasn't important, but I was shocked to how good the Atmega PWM was. Most modern digital power supplies do not have the resolution.

Thanks to you, I now I find it is not the only magic that you can do with an Atmega processor.

Richard.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on February 26, 2013, 03:28:24 am

Thanks! You're welcome! I forwarded the URL of this thread to Karl-Heinz, so he can enjoy this too ;-)

Quote

Markus and Karl-Heinz,-

When I stumbled on this Chinese-made gizmo, I had no idea of  the history and background behind it. Reading all of the above (and the documentation) I realize now what a truly impressive project this is and I thank you for all your efforts. Beyond the ingenuity of squeezing so much out of a processor that wasn't purpose-built for the task, the end result is a very useful tool in and of itself. I will have to explore further the two enhancements (cap discharge and zener diode) that you mention.

Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on February 26, 2013, 04:56:54 am
Maybe a kit with the leads, shielded bannana plugs and clips included? And a separate battery compartment. I would definitely want a separate battery compartment. What other features would you look for and how much would something like that be worth to you?

Torch, thanks for the heads up, I would like to build one myself, it is fun for me to do so. Right now I ordered some parts for my DMMCheck, I mailed with the maker (Doug) to have some ideas so I don’t make something which makes the DMMCheck go out spec.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 26, 2013, 05:59:27 am
If you are interested, take a look at this post first. When I did this test, I was going to be happy if I achieved better then 1% accuracy:

http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/150/ (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/150/)

If that gets you interested, then the first relevant post is here:

http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/msg99807/#msg99807 (http://www.eevblog.com/forum/projects/general-purpose-power-supply-design-7488/msg99807/#msg99807)

It is a long thread unfortunately.

That's also a great project! The idea to generate a MCU driven adjustable voltage reference to optimize accuracy and resolution for low voltages is compelling. Much better than the internal bandgap reference.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on March 08, 2013, 08:35:53 am
I received my tester today, I measured couple resistors and capacitors and this is little fun device to play with. I am not sure how the accuracy is but known values looks okay, and that is not that important at this price.

Now I need some time to make a case for it. 
Title: Re: $20 LCR ESR Transistor checker project
Post by: -DOM- on March 15, 2013, 02:19:50 pm
I read elsewhere on the forums that this doesnt support in circuit esr readings. Have you tried? I am not after a super accurate measurement just to tell if a cap is bad.

Once i have done enough repairs i hope to by a proper tester although i just cant justify it at this stage.

cheers damien
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 15, 2013, 03:44:18 pm
Spawn, please, share the scope's shot on the measuring signals at the probe from open connection to different DUTs.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on March 15, 2013, 05:11:05 pm
I read elsewhere on the forums that this doesnt support in circuit esr readings. Have you tried? I am not after a super accurate measurement just to tell if a cap is bad.
No - you would definitely be much better off using a meter designed for ESR measuring at 100kHz. You cannot even force the ESR to tests the attached device as a capacitor - it makes a best guess, and who knows what guess it will come up with in an in-circuit test. It also has zero protection and trying to add protection any interfere with other device readings. A good ESR meter will hopefully have some ability to survive some residual charge on a capacitor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 15, 2013, 05:41:15 pm
No - you would definitely be much better off using a meter designed for ESR measuring at 100kHz.
Why Richard ? Is that because of common power caps are rated at 100Khz ? or other reasons ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on March 15, 2013, 05:47:59 pm
No - you would definitely be much better off using a meter designed for ESR measuring at 100kHz.
Why Richard ? Is that because of common power caps are rated at 100Khz ? or other reasons ?
Because at 100kHz, the ESR resistance is much larger then the impedance due to the capacitance so it is easy to measure the ESR accurately. For example a 100uF cap has 16 milliohms impedance due to the capacitance. A 2000uF cap has less then 1 milliohm due to the capacitance and that is about the resolution limit of the best in-circuit esr meters. It is really easy to see a 20 milliohm esr when it is in series with 1 milliohm capacitive impedance.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 15, 2013, 05:55:58 pm
No - you would definitely be much better off using a meter designed for ESR measuring at 100kHz.
Why Richard ? Is that because of common power caps are rated at 100Khz ? or other reasons ?
Because at 100kHz, the ESR resistance is much larger then the impedance due to the capacitance so it is easy to measure the ESR accurately. For example a 100uF cap has 16 milliohms impedance due to the capacitance. A 2000uF cap has less then 1 milliohm due to the capacitance and that is about the resolution limit of the best in-circuit esr meters. It is really easy to see a 20 milliohm esr when it is in series with 1 milliohm capacitive impedance.
Thanks, noted.  :-+

Ok, a bit offtopic, but this times about the "circuit design", is there any significant "challenge" to design/make the LCR measurement circuit that capable of max 100KHz vs 10KHz ? Or other non technical concerns maybe ?

Cause at commercial LCR meters, the price difference is quite significant, why is that ?  ???
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on March 15, 2013, 06:14:11 pm
Ok, a bit offtopic, but this times about the "circuit design", is there any significant "challenge" to design/make the LCR measurement circuit that capable of max 100KHz vs 10KHz ? Or other non technical concerns maybe ?

Cause at commercial LCR meters, the price difference is quite significant, why is that ?  ???
It is simply that there are many sources of error, particularly at 100kHz, the designers have to track each one down and see what they can do to reduce or eliminate that source of error. Sometimes they can find a way for the software to measure the internal error, and eliminate it from the result through calculation. Sometimes it just means lots of PCB layout revisions. Sometimes very small changes in design make a big improvement in accuracy. It can mean trying just about every analog switch on the market to find the one that performs the best.

So the difference between an top Agilent meter, and a cheap no-name Chinese one is the amount of time the designers spend polishing the design. The cheap one is probably a close copy of a chipsets manufacturer's sample circuit, or closely based on another company's design - but without the knowledge that that other company had in optimizing the performance.

Even though a final circuit can look reasonably simple, the chances of one of us designing a meter to equal an Agilent one on a first attempt is pretty low.

Then again, you never know if you don't try.  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 15, 2013, 06:18:43 pm
Got it, great knowledge learned here ! Thanks again !  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on March 15, 2013, 10:51:21 pm
Spawn, please, share the scope's shot on the measuring signals at the probe from open connection to different DUTs.

I don’t have DSO BravoV but I got a CRO with digital storage so I can take picture of it, what values do you want me to measure? I got most common capacitors ceramic and electrolytic and I can compare it to my crappy UT603 if you want  ^-^
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 15, 2013, 11:47:25 pm
I don’t have DSO BravoV but I got a CRO with digital storage so I can take picture of it, what values do you want me to measure? I got most common capacitors ceramic and electrolytic and I can compare it to my crappy UT603 if you want  ^-^
1st is open connection, no DUT, straight from the test probes, 2nd a known low esr cap, and last that low esr cap series with a resistor or a known high esr cap. Really appreciate and thanks for trouble.  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on March 16, 2013, 12:12:02 am
No - you would definitely be much better off using a meter designed for ESR measuring at 100kHz. You cannot even force the ESR to tests the attached device as a capacitor - it makes a best guess, and who knows what guess it will come up with in an in-circuit test. It also has zero protection and trying to add protection any interfere with other device readings. A good ESR meter will hopefully have some ability to survive some residual charge on a capacitor.

With a frequency of 680Hz, this device is limited in it's ability to test low value caps even out of circuit. I think it's OK for most electrolytic caps though. Provided it picks up the DUT as a cap, and provided the cap is discharged, and provided the cap is within the appropriate range, I don't see any reason why it can't work in-circuit as compared to a dedicated ESR meter.

As for protection, I wonder if a simple NC relay would suffice for some measure of protection? If the relay contacts were opened by the power-on sequence, they would discharge the cap on connecting the leads then effectively drop out of the circuit when the test button was pushed.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on March 16, 2013, 05:51:21 am
1st is open connection, no DUT, straight from the test probes, 2nd a known low esr cap, and last that low esr cap series with a resistor or a known high esr cap. Really appreciate and thanks for trouble.  :-+

Okay  :-+ I will do that in a bit, don’t have caps with known ESR value but I will figure out something.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on March 16, 2013, 09:08:57 am
Okay BravoV, this thing is doing weird stuff  :-DD

Trying capture anything with a 4k storage was a real task, I could only capture in magnified sec/div at 5nS but the thing is this tester puts out different waveforms till it can measure and I could only capture the last one and the frequency of these are really odd. I think a DSO with proper storage could see a lot more. Maybe someone with a decent scope can help us?

Directly probed on the test inputs puts out 100MHz, which is weird and it also measures the input resistance of the scope with 9762kohm:
(http://i193.photobucket.com/albums/z298/Bl4ckW0lfi3/empty_test_zps8e88f78a.jpg)

Another weird measurement, with 100uF 20% cap, my scope couldn’t measure one or two waves so I grabbed 3 waves and it reads 0.0833GHz, LCR tester reads 2.7ohms:
(http://i193.photobucket.com/albums/z298/Bl4ckW0lfi3/100uF_27esr_cap_zps5c9d0052.jpg)

Here testing 10ohm resistor, while testing this LCR tester knows it is a resistor and it doesn’t put out any frequency, the wave on scope is from last measurement with cap:
(http://i193.photobucket.com/albums/z298/Bl4ckW0lfi3/10ohm_resistor_zpsaa1eeb3a.jpg)

Testing same 100uF cap and 10ohm resistor in series doesn’t change the output frequency, it stays same as when you test the cap, even the waveform stays same, oddly LCR tester measures the cap value little higher:
(http://i193.photobucket.com/albums/z298/Bl4ckW0lfi3/100uF_and_10ohm_zps16cc5520.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 16, 2013, 05:56:35 pm
Hey Spawn, thanks a lot !  :-+

Trying capture anything with a 4k storage was a real task, I could only capture in magnified sec/div at 5nS but the thing is this tester puts out different waveforms till it can measure and I could only capture the last one and the frequency of these are really odd. I think a DSO with proper storage could see a lot more. Maybe someone with a decent scope can help us?
Yeah, that signal kinda weird and has unique pattern at the 1st test on open connection. And it looks like a square wave with quite slow rise/fall time to me ? Is it the scope speed limitation ?

Anyone with high speed scope, please share the test signal please.


Its cool to see it could measure your probe's input resistance at 1Meg ohm.

Looking at the test signal, at vertical about 2V, your scope shows the signal's Vpp is about 8.x Volt, and wonder if this high voltage could do harm on low voltage capacitor like 6.3 Volt or even those 2.5 or 1.8 volt expensive polymer caps ?  ???
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 16, 2013, 06:39:55 pm
Anyone with high speed scope, please share the test signal please.

There's no need for high end gear ;-) Just check out the source code! Large caps are charged with pulses until a specific voltage is reached. Multiply the number of pulses with the pulse width and you'll have the time. Then use the famous equation for charging capacitors to get the capacitance.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 16, 2013, 06:46:58 pm
Anyone with high speed scope, please share the test signal please.

There's no need for high end gear ;-) Just check out the source code! Large caps are charged with pulses until a specific voltage is reached. Multiply the number of pulses with the pulse width and you'll have the time. Then use the famous equation for charging capacitors to get the capacitance.
OIC, thanks Markus for the the explanation on the cap measurement method ! Its just I'm lazy to go through the source code !  ;D

As my question, so this thing can not be used on low voltage cap ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on March 16, 2013, 10:00:44 pm
OIC, thanks Markus for the the explanation on the cap measurement method ! Its just I'm lazy to go through the source code !  ;D

As my question, so this thing can not be used on low voltage cap ?

You don't even have to decypher the source code. It's covered in the documentation that was posted on page 1 of this thread:

5.3.2 Measurement of big Capacitors
One side of the capacitor is connected to GND. The other side of the capacitor is connected with
the 680  resistor to VCC for a period of 10ms. Afterwards this probe pin is switched to Input (High
Impedance). After this 10 ms current pulse the voltage of the capacitor is measured without any
current. If the voltage has not reached a minimal value of 300mV, the load pulse is repeated up to
499 times. If after 127 pulses a minimum voltage of 75mV is not reached (about 2s), further load
is stopped, because never the 300mV can be reached with the remaining load pulses. Figure 5.21
shows the three phases of measuring the capacity value of a capacitor. The value of the capacity is
then computed with the count of load pulses and the reached load voltage from a table. The table
contains the factors to get the capacity in nF units from load time and the reached voltage with a
spacing of 25mV. Interim value of voltage will be interpolated.

Now I realize that VCC in this case is 5v, which is technically above the 1.8v you are concerned about. For all of 10ms. I don't really know much about such low voltage caps or if they are robust enough to take a brief pulse, but certainly the 6.3 volt caps are in no danger.

Personally, the highest voltage I saw on the scope during my own experimenting was about 3.5v, but I don't remember how big the cap was. It might well go higher with a low-value cap.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on March 16, 2013, 10:55:35 pm
Unless I'm reading Spawn's scope shots wrongly and CMIIW, isn't that his test voltages are quite high ?  :-//
Title: Re: $20 LCR ESR Transistor checker project
Post by: Spawn on March 17, 2013, 12:42:10 am
Yes indeed my scope reads around 8volts, you can see the volt/div switch on channel 1 at 2volts, probe is 10x Tek P6109. About the speed BravoV, I could go one lower in magnified situation to 5ns that’s the fastest it gets but the signal got so vague I couldn’t see where to put the cursors to measure something.

Other important thing I forgot to mention is, I had a fresh battery every time when you push the button it tests the battery, at the start it was 9.5volts after around 20 tests while I was trying to find good setting on my scope to get a waveform it dropped to 8.9volts. I am not sure how many tests you can do with caps, I could give a go on a fresh battery and average value cap to see that but then it will be waste of my 9volt battery  ^-^
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 17, 2013, 09:58:49 am
OIC, thanks Markus for the the explanation on the cap measurement method ! Its just I'm lazy to go through the source code !  ;D

You're welcome! Who isn't lazy? :-)

Quote
As my question, so this thing can not be used on low voltage cap ?

The charging of any cap stops at about 1300mV maximum. And for large caps (>50µF) the current is limited by a 680 Ohms resistor (@5V), i.e. about 7mA. For small caps it's a 470k resistor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: space_bastard on March 17, 2013, 11:28:07 am
Awesome build! Just came across this diy ESR meter on Hackaday:

http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/ (http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/)

I have been looking for a cheap way to test caps, I may have to look into a diy solution!
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on March 17, 2013, 12:15:31 pm
Awesome build! Just came across this diy ESR meter on Hackaday:

http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/ (http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/)

I have been looking for a cheap way to test caps, I may have to look into a diy solution!

I looked at the design today also.  And decided to build one. So tore down a couple of pc power supplies to rob the step down transformers out of. But ended up making 2 bench power supplies out of them.  :-//

Anyway ordered the one posted here in this thread today.
Title: Re: $20 LCR ESR Transistor checker project
Post by: notsob on March 17, 2013, 12:30:37 pm
And here's an interesting one, by Fr Tom McGahee on his cap meter design, pcb pdf's and PIC code available (of course you'll have to modify the code for a later version PIC)
Title: Re: $20 LCR ESR Transistor checker project
Post by: space_bastard on March 17, 2013, 04:53:09 pm
Awesome build! Just came across this diy ESR meter on Hackaday:

http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/ (http://hackaday.com/2013/03/16/testing-caps-with-a-diy-esr-meter/)

I have been looking for a cheap way to test caps, I may have to look into a diy solution!

I looked at the design today also.  And decided to build one. So tore down a couple of pc power supplies to rob the step down transformers out of. But ended up making 2 bench power supplies out of them.  :-//

Anyway ordered the one posted here in this thread today.

You can never have too many power supplies!  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 26, 2013, 04:13:02 am
My new firmware 1.06m is released. New features are an improved UI, use of the MCU sleep modes to reduce power consumption (as in 1.06k) and a PWM generator. You can choose between several pre-defined frequencies in a menu and increase or decrease the duty ratio in steps of 5%. But beware :-) No ESR or L measurements are supported (if you need those go for 1.06k).

You'll find all firmwares and docs at http://www.mikrocontroller.net/svnbrowser/transistortester/. (http://www.mikrocontroller.net/svnbrowser/transistortester/.) The m-version is located under Software/Markus.

Have fun!
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on March 26, 2013, 04:07:56 pm
Thanks Markus.

Any reason for removing ESR and L? Is this an issue of code space in the Atmega168 ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on March 27, 2013, 03:52:13 am
Markus,
Do you still offer compile code?
Thank you very much :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 27, 2013, 09:13:32 am
Any reason for removing ESR and L? Is this an issue of code space in the Atmega168 ?

Never added those to my firmware fork :-) Some time ago when Karl-Heinz was adding the inductance measurement (k version) I also played with that but dropped it because the measurement range is very limited. Later Karl-Heinz expanded the range by running the ATmega out-of-spec for a short period of time (so far no ATmega died from that :-). The ESR measurement was similar and don't forget the odd test frequency. I don't think that there's much gain by ESR and L measurements with quite limited ranges. A dedicated LCR meter is much better for that. And yes, the ATmega168 is nearly maxed out.

PS: Karl-Heinz is improving the ESR measurement at the moment.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 27, 2013, 09:26:06 am
Do you still offer compile code?

It's open source software and hardware. Nothing to hide :-) Karl-Heinz always creates a few precompiled firmwares for some common hardware
setups (for the lazy :-).

Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on March 27, 2013, 10:31:40 am
I got my tester in yesterday, but was too sick to play with it. I did get a chance to use it tonight. Very nice. I like it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on March 29, 2013, 08:48:05 am
Actually Lazy is one of my nicknames :)
I originally purchased the semiconductor tester from www.warf.com (http://www.warf.com) as it comes with a nice case. it worked well but it had a couple of bugs on the firmware. I purchased a couple of Atmega8 and and the USB ASP to be able to program the chips, download the pre-compiled software and programmed the chips with the AVR extreme burner. It worked fine but then I found out that Karl was working on an improved version of your original design so I purchased the other version of the component tester version 2.2 on exxy.com and also a couple of Atmega328 to play with. I haven't compiled for a long time. I come from a strictly assembly language background (z80, 8088, 6800, 8051, 68HC11) so here I am again downloading the WinAvr suite and trying to figure out how to use it. I just wanted to try your newest version of the firmware on my original design hardware. Yeah, It might take me a couple of nights to figure out how to compile the code ......... call me lazy :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 29, 2013, 10:14:50 am
software and programmed the chips with the AVR extreme burner. It worked fine but then I found out that Karl was working on an improved version of your original design so I purchased the other version of the component tester version 2.2 on exxy.com and also a couple of Atmega328 to play with.

The original design was done by another Markus. I joined Karl-Heinz last year.

Quote
I haven't compiled for a long time. I come from a strictly assembly language background (z80, 8088, 6800, 8051, 68HC11) so here I am again downloading the WinAvr suite and trying to figure out how to use it.

Still got my 68HC11 developer board ;-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on March 31, 2013, 01:08:04 pm
Blah, was going to use the new tester today for the first time in a real world test. Bloody thing failed to come on.  :palm: I only tested new caps out of the parts bin since I had it.  So today someone brought over a board with possible caps bad.  I said hey, let me show you thing neat gadget I just got. And it would not turn on   :-BROKE Boy did I feel stupid. Anyway I will give anything a second try. So I ordered another one.  |O
Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on March 31, 2013, 01:40:44 pm
And it would not turn on   :-BROKE Boy did I feel stupid. Anyway I will give anything a second try. So I ordered another one.  |O
You didn't unplug the display, and then plug it back - but out by one pin? Easy to do.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on March 31, 2013, 01:48:31 pm
And it would not turn on   :-BROKE Boy did I feel stupid. Anyway I will give anything a second try. So I ordered another one.  |O
You didn't unplug the display, and then plug it back - but out by one pin? Easy to do.

Nope. Wish it had been that easy lol.  Thought maybe a bad battery. But it was good. tried another to be sure. Got voltage on the board but no display. The red LED will not come on either. Probably controller failure. When I get the cance this week I will do a bit more troubleshooting. The Ebay seller offered to replace it. Told him no worries I will just order another, so I did. Now I have one to tear down  :-DD
Title: Re: $20 LCR ESR Transistor checker project
Post by: kubi48 on April 20, 2013, 05:00:00 pm
Hello,
I would like to tell you, that a new version of my TransistorTester software is ready for download from the mikrocontroller.net site.
The main advantage of the new version is a improved ESR measurement, which can now determine ESR for capacitors with more than 0.18 uF. The new approach use shorter current pulses to measure the ESR.
Additionally this method can be used to measure resistors too. This gives a resolution of 0.01 Ohm for resistors with less than 10 Ohm and the calibration use this function to measure the zero resistance. So no more the extra calibration of ESR zero with big capacitors is required. In the majority of cases the new ESR measurement gives lower results because the shorter pulses make the result more like a 10 kHz measurement.
Additionally a new parameter is output for capacitors with more than 5000 pF and low quality factor. This parameter is the voltage loss (Vloss) immediately after a load pulse. Some older paper capacitors make problems to get the right capacity. The error can be more than 100%. Also other instruments have problems to measure the right capacity for that capacitors. For this type of capacitor a voltage loss of more than 10% was measured, so the TransistorTester gives you a warning hint with the Vloss now.

Title: Re: $20 LCR ESR Transistor checker project
Post by: amspire on April 20, 2013, 06:22:40 pm
That's at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/) I guess. V107 is only 21 hours old.

Here is a Google Translate of the changelog:
Quote
Makefile option NO_NANO Specific activity complements.
Extended function GetVloss for capacitors with more than 5nF, previously 50nF.
The self-test Let's remove the short-circuit test at 4 is monitored, AllProbesShorted by Markus R.
The GetESR function is used during calibration to determine the zero resistance (pin-dependent).
GetESR function is also used for resistance values ??below 10 ohms.
Function GetESR replaced by new assembler function.
New feature GetVloss to measure the voltage drop after a charge pulse at small 45uF capacitors.
The GetESR function converted to assembler to make the time sequence regardless of the compiler optimization.
Assignment of Flash and EEPROM memory optimized.
BAT_POOR level changed in the Makefile to mV indication, indication of just 1.3V +0.1 V warning.
ESR measurement for capacitors from 0.45uF supplemented with 500kHz ADC clock.
The resolution of the inductance is set to 0.1mH Resistance 680 ohms.
The Pinreihenfolge with individual diodes is issued in accordance ATmega168/328 EBC_STYLE.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on April 20, 2013, 08:16:53 pm
Well this sounds intriguing!

I've never played with these AT projects. A quick google tells me there are a variety of ways to upload programming to these chips.  The Chinese board seems to have a 10 pin unpopulated header that might be the interface for the soldered processor. Can anyone confirm this?

Supplementary question: does this look like a suitable programmer: http://www.ebay.com/itm/USB-ISP-Programmer-for-ATMEL-AVR-51-ATMega-ATTiny-/200460739146 (http://www.ebay.com/itm/USB-ISP-Programmer-for-ATMEL-AVR-51-ATMega-ATTiny-/200460739146) ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: kubi48 on April 20, 2013, 08:59:33 pm
The chinese board uses a 10 pin ISP header. The ISP interface is specified as 10 pin or 6 pin header.
I don't know anything about the quality of the ISP programmer with USB interface in your link.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 21, 2013, 01:43:07 am
I've never played with these AT projects. A quick google tells me there are a variety of ways to upload programming to these chips.  The Chinese board seems to have a 10 pin unpopulated header that might be the interface for the soldered processor. Can anyone confirm this?

The 6 or 10 pin header is the ISP interface supported by ATtiny and ATmega MCUs. The drawback of the ISP interface is that it can't be used if the fuses are messed up badly. In that case you'll need a so called HV parallel programmer. AFAIK the Dragon board supports both methods.

Quote
Supplementary question: does this look like a suitable programmer: http://www.ebay.com/itm/USB-ISP-Programmer-for-ATMEL-AVR-51-ATMega-ATTiny-/200460739146 (http://www.ebay.com/itm/USB-ISP-Programmer-for-ATMEL-AVR-51-ATMega-ATTiny-/200460739146) ?

Make sure the progammer is supported by avrdude or is compatible with STK-500.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on April 21, 2013, 07:13:13 am
Well, according to Mr. Karl-Heinz Kübbeler (in his excellent documentation referenced on page 1 of this thread) when he tested one of the Chinese versions:

Quote
The lock fuses of the ATmega were set, so no readout was possible. But I could install the software version 1.05k without any problems.

He doesn't specify exactly what method he used to install the software, but I will guess he used the ISP header interface since he mentions it earlier in the section, and I think he would have said something if it didn't work.

The unit I found on fleabay indicates it is is "based on Thomas Fischl's USBasp design". I found a tutorial on using USBasp with Avrdude, so my guess is that it is compatible. However, that particular unit comes with Chinese language software/manual only, so I think I'll keep looking for something with English support. I will have enough trouble understanding the English...  :-DD
Title: Re: $20 LCR ESR Transistor checker project
Post by: hunter on April 22, 2013, 01:40:42 pm
I would like to know if it is possible to reflash/update the firmware on the chip with Arduino board. They seem to use ATmega chip as well. Is it same procedure as with normal Arduino code ?

The old one uses removable chip , while the new one has a tiny chip soldered. So I am sure the new one is not update able.  ???

Old one: /ebay
(http://i.ebayimg.com/t/NEWEST-AVR-Transistor-Tester-meter-NPN-PNP-MOSFET-diode-triac-resistor-capacitor-/00/s/NjAwWDgwMA==/z/kyMAAMXQTghRN2mj/$T2eC16dHJHIE9nysfBj6BRN2mjs4,!~~60_3.JPG)

New one: /ebay
(http://hk2.image.pushauction.com/ViewPicture.aspx?Key=46ec5f0d-de2b-4456-ac5f-730737bb6a3b_d572ea3c-8092-46dc-9074-02c580022aa5)
Title: Re: $20 LCR ESR Transistor checker project
Post by: ecat on April 22, 2013, 07:41:40 pm
@hunter

See the 10 holes (5x2) on the left side of the new board?
High probability these are for a programming header :)

Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on April 22, 2013, 07:46:14 pm
That's the one I have. I believe the 10 unpopulated holes on the left side are the ISP programming header. I'm going to try upgrading to V1.07 with this Usbasp programmer: http://www.ebay.com/itm/300695243866. (http://www.ebay.com/itm/300695243866.) It specifically mentions it is compatible with the avrdude software as recommended by madires.

I'll let you know if it works once the programmer arrives and I have time to figure this out.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 22, 2013, 09:42:52 pm
See the 10 holes (5x2) on the left side of the new board?
High probability these are for a programming header :)

Good guess! :-)  Please see http://www.batsocks.co.uk/readme/isp_headers.htm (http://www.batsocks.co.uk/readme/isp_headers.htm) for the 6 and 10pin ISP headers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: kubi48 on April 23, 2013, 12:18:10 am
Here is my early version of the new Tester with some modifications.
The 10-pin ISP header is soldered, but one side of the frame must be cut out
to match the room left for the header.
The original potentiometer has been replaced to a exemplar with higher resistance
(10k) to save power.
Two blocking capacitors of 100nF each are additionally mounted near the ATmega.
The D1 zener diode is replaced by a precision voltage reference like LM4040AIZ2.5 .
If you don't have a precision voltage reference, you should remove the zener diode at least.
I had also replaced the original 78L05 regulator by my preferred MCP1702-5002 regulator,
because this regulator can also save quiescent current.
Regards, Karl-Heinz
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on July 15, 2013, 04:21:48 pm
Karl-Heinz (the current main developer of the software) started to implement an enhanced software for the 328 in the current trunk http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/)

This version uses the additional space to measures the current amplification in emitter and collector configuration (don't know the correct english term here, perhaps I should visit english for engineers next semester).

And, as there are many problems in the thread at http://www.mikrocontroller.net/topic/248078 (http://www.mikrocontroller.net/topic/248078) due to sleep mode and wrong oscillator, just a little hint:
When using sleep modes and the internal RC oscillator, you have to set 'RESTART_DELAY_TICS=6' because the wake up is faster and therefore timing is calculated wrong so that you will get wrong capacitor values.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 18, 2013, 02:38:02 am
1.09m is released:
- fixed a pin assignment bug for MOSFETs
- leakage current is considered for hFE now
- detection of IGBTs (if the tester is able to exceed the gate threshold voltage)

http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/)
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on July 18, 2013, 03:14:41 am
Nice!!!  :-+ :-+ :-+

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on July 19, 2013, 01:18:31 am
Damn it, Markus and Karl-Heinz!
You made me succumb to the temptation of ignoring your project and, finally, to build that relentless spare-time killing device*! :)

Kidding aside, please let me contribute a little something to this fine project, and feel free to use it at will. This will be a surprisingly accurate version of the Sleep_5ms/MilliSleep time delay functions you already make use of.

The following version of the sleep-time delay breaks down the total requested sleep-time to three partial and very accurate TC2 wait times of 16.00 ms, 3.00 ms and 1.00 ms. Additionally, it utilises the Extended Standby Sleep Mode instead of the Idle Sleep Mode (that introduces timing errors for reasons currently unknown to me). Trying to keep the function spartan, the resulting timing error is a couple (or three or four in the worst case!) microseconds only, regardless of the total requested time delay, which is in the range of 1.00 ms to 65535.00 ms!

There are two problems, though:
The obvious one is that this function has to be ported to C, in order to be utilised in the current project --which is a trivial task.
The second one is that, in its current form, the function does only support the crystal oscillator option at 8.0 MHz (that I use in my implementation), since the RC oscillator needs very different start-up times and makes the redefinition of the partial delays an absolute requirement. Of course, the function can be rewritten to support the 16.0 MHz crystal oscillator or the 8 MHz RC oscillator option.

This is the assembly code:

Code: [Select]
;-------------------------------------------------------------------------------
; Registers definitions
;-------------------------------------------------------------------------------
;.def = r0 ; Temp / Product of the MULx instructions: [r1:r0]
;.def = r1 ;
.def C0 = r2 ; Temp / Math registers: [C7:C0]
.def C1 = r3 ;
.def C2 = r4 ;
.def C3 = r5 ;
.def C4 = r6 ;
.def C5 = r7 ;
.def C6 = r8 ;
.def C7 = r9 ;
.def D0 = r10 ; Temp / Math registers: [D3:D0]
.def D1 = r11 ;
.def D2 = r12 ;
.def D3 = r13 ;
;.def = r14 ; Ct. = 0xFF
.def Zero = r15 ; Ct. = 0x00
.def A0 = r16 ; Temp / Math registers: [A3:A0]
.def A1 = r17 ;
.def A2 = r18 ;
.def A3 = r19 ;
.def B0 = r20 ; Temp / Math registers: [B3:B0]
.def B1 = r21 ;
.def B2 = r22 ;
.def B3 = r23 ;
.def T0 = r24 ; 16-bit temp: [T1:T0]
.def T1 = r25 ;
;.def XL = r26 ; X pointer: [XH:XL]
;.def XH = r27 ;
;.def YL = r28 ; Y pointer: [YH:YL]
;.def YH = r29 ;
;.def ZL = r30 ; Z pointer: [ZH:ZL]
;.def ZH = r31 ;


;-------------------------------------------------------------------------------
Sleep_1ms_Init: ; <Sleep_1ms> function initialisation
;-------------------------------------------------------------------------------
;     Initialisation of the <Sleep_1ms> function
;
; Syntax:
; call Sleep_1ms_Init ; Initialise the <Sleep_1ms> function
;
; <Sleep_1ms_Init> Parameters:
;   None!
; <Sleep_1ms_Init> Returns:
;   None!
;
; Registers used:
;   Zero;  Non-destructive use of <Zero> that can be any CPU register loaded with the constant value of 0x00
;   A0;    Non-destructive use of <A0> that can be any of the CPU high-registers (r16..r31)
;
push A0 ; Preserve the <A0> temp
; Stop and disable TC2 and TC2 ISRs
sts TCCR2B,Zero ; [FOC2A,FOC2B,-,-,WGM22,CS22,CS21,CS20]
sts TIMSK2,Zero ; [-,-,-,-,-,OCIE2B,OCIE2A,TOIE2]
sts TCNT2,Zero ; Reset TC2
; Set TC2 mode to CTC (WGM22:20 = 0b010)
ldi A0,1<<WGM21 ; Mode 2 (CTC): WGM22:20 = 0b010
sts TCCR2A,A0 ; [COM2A1,COM2A0,COM2B1,COM2B0,-,-,WGM21,WGM20]
sts ASSR,Zero ; [-,EXCLK,AS2,TCN2UB,OCR2AUB,OCR2BUB,TCR2AUB,TCR2BUB]
; Avoid any TIM2_COMPA ISR firing caused by possible low values loaded to OCR2A
ldi A0,-1 ;
out TIFR2,A0 ; [-,-,-,-,-,OCF2B,OCF2A,TOV2]
sts OCR2A,A0
; Done!
; cbi PORTC,3 ; ########  D E B U G G I N G  ########
; cbi PORTC,4 ; ########  D E B U G G I N G  ########
; sbi DDRC,3 ; ########  D E B U G G I N G  ########
; sbi DDRC,4 ; ########  D E B U G G I N G  ########
pop A0 ; Restore the <A0> temp
ret


;-------------------------------------------------------------------------------
Sleep_1ms: ; Sleep for <T1:T0> * 1 ms time
;-------------------------------------------------------------------------------
;     Set the CPU to sleep for <T1:T0> times 1ms
;
; Syntax:
; ldi T0,Byte1(Delay) ; <Delay> is the requested sleep-time delay
; ldi T1,Byte2(Delay) ;  in 1 ms steps. Range: Delay = 1..65535
; call Sleep_1ms ; Sleep for <T1:T0> * 1 ms time
;
; <Sleep_1ms> Parameters:
;   T1:T0 = 1..65535, in 1 ms steps
; <Sleep_1ms> Returns:
;   None!
;
; Registers used:
;   Zero;  Non-destructive use of <Zero> that can be any CPU register loaded with the constant value of 0x00
;   A0;    Non-destructive use of <A0> temp that can be any of the CPU high-registers (r16..r31)
;   T1:T0; Destructive use of <T1:T0> that should be any of the 16-bit addressing capable register pairs (r25:r24, X, Y or Z)
;
.equ Restart_Delay_Tics = 16384                            ; CPU restart delay, in Clk cycles
.equ Restart_Delay = Restart_Delay_Tics*1000000/F_CPU ; 2048 ms for 8 MHz clock
.equ T2_Period_004 =    32 * 1000000/F_CPU            ;    4 µs for 8 MHz clock
.equ T2_Period_128 =  1024 * 1000000/F_CPU            ;  128 µs for 8 MHz clock
; Preamble
; sbi PORTC,3 ; ########  D E B U G G I N G  ########
push A0 ; Preserve the <A0> temp
ldi A0,1<<OCIE2A ; Enable the TC2 Output Compare Match A interrupt
out TIFR2,A0 ; [-,-,-,-,-,OCF2B,OCF2A,TOV2]
sts TIMSK2,A0 ; [-,-,-,-,-,OCIE2B,OCIE2A,TOIE2]
sei ; Now, we can safely enable global interrupts

; <T1:T0>: Delay register, in 1.0 ms units step
 _Slp1ms_Dly: wdr ; Prevent a WD timeout event
; sbi PORTC,4 ; ########  D E B U G G I N G  ########
; Fast Clk (4 µs / 250 kHz)
ldi A0,1<<CS21|1<<CS20 ; T2_Period = Clk/32 = 4 µs
sts TCCR2B,A0 ; [FOC2A,FOC2B,-,-,WGM22,CS22,CS21,CS20]
ldi A0,1<<PSRASY ; TC2 prescaller reset
out GTCCR,A0 ; [TSM,-,-,-,-,-,PSRASY,PSRSYNC]
sts TCNT2,Zero ; Reset TC2
; Delay module (1/3/16 ms)
cpi T0,Byte1(3)
cpc T1,Zero
brlo _Slp1ms_01m ; Delay < 3 ms
cpi T0,Byte1(16)
cpc T1,Zero
brlo _Slp1ms_03m ; Delay < 16 ms
; Slow Clk (128 µs / 7812.5 Hz)
ldi A0,1<<CS22|1<<CS21|1<<CS20 ; T2_Period = Clk/1024 = 128 µs
sts TCCR2B,A0 ; [FOC2A,FOC2B,-,-,WGM22,CS22,CS21,CS20]
ldi A0,1<<PSRASY ; TC2 prescaller reset
out GTCCR,A0 ; [TSM,-,-,-,-,-,PSRASY,PSRSYNC]
sts TCNT2,Zero ; Reset TC2

; 16.00 ms to sleep: Use the Power Save Sleep Mode
;  OCR2A = ((16000µs-2048µs)/128µs)-1 = (13952µs/128µµs)-1 = 109-1
 _Slp1ms_16m: ldi A0,((16000-Restart_Delay)/T2_Period_128)-1
sts OCR2A,A0
; Set the Sleep Mode to Power Save (SM2:0 = 0b011)
ldi A0,1<<SM1|1<<SM0|1<<SE
out SMCR,A0 ; [-,-,-,-,SM2,SM1,SM0,SE]
sleep
; Update the Delay register
sbiw T0,16 ; Delay register timed-out?
; cbi PORTC,4 ; ########  D E B U G G I N G  ########
brne _Slp1ms_Dly ;  Not yet. Else:
rjmp __Slp1ms_X

; 3.00 ms to sleep: Use the Power Save Sleep Mode
;  OCR2A = ((3000µs-2048µs)/4µs)-1 = (952µs/4µs)-1 = 238-1
 _Slp1ms_03m: ldi A0,((3000-Restart_Delay)/T2_Period_004)-1
sts OCR2A,A0
; Set the Sleep Mode to Power Save (SM2:0 = 0b011)
ldi A0,1<<SM1|1<<SM0|1<<SE
out SMCR,A0 ; [-,-,-,-,SM2,SM1,SM0,SE]
sleep
; Update the Delay register
sbiw T0,3 ; Delay register timed-out?
; cbi PORTC,4 ; ########  D E B U G G I N G  ########
brne _Slp1ms_Dly ;  Not yet. Else:
rjmp __Slp1ms_X

; 1.00 ms to sleep: Use the Extended Standby Sleep Mode (no Restart Delay)
;  OCR2A = (1000µs/4µs)-1 = 250-1
 _Slp1ms_01m: ldi A0,(1000/T2_Period_004)-1
sts OCR2A,A0
; Set the Sleep Mode to Extended Standby (SM2:0 = 0b111)
ldi A0,1<<SM2|1<<SM1|1<<SM0|1<<SE
out SMCR,A0 ; [-,-,-,-,SM2,SM1,SM0,SE]
sleep
; Update the Delay register
sbiw T0,1 ; Delay register timed-out?
; cbi PORTC,4 ; ########  D E B U G G I N G  ########
brne _Slp1ms_Dly ;  Not yet. Else:

; Done! Stop TCNT2 and disable OCIE2A and the Sleep Modes
 __Slp1ms_X: sts TCCR2B,Zero ; [FOC2A,FOC2B,-,-,WGM22,CS22,CS21,CS20]
sts TIMSK2,Zero ; [-,-,-,-,-,OCIE2B,OCIE2A,TOIE2]
out SMCR,Zero ; [-,-,-,-,SM2,SM1,SM0,SE]
pop A0 ; Restore the <A0> temp
; cbi PORTC,3 ; ########  D E B U G G I N G  ########
ret

-George


EDIT:
Corrections of the premature and incomplete assembler code that was mistakenly posted.


(*) Here are a few ideas that might be of some use for the project.
This is my hardware version of a single layer PCB, an easy one to be built at home, with the following modifications:
- Additional PCB space to host a 9V battery, for an autonomous and completely floating testing device.
- The use of the more accurate and flexible LP2950-5.0 LDO/reference, which eliminates the need for an external voltage reference diode.
- The addition of R2 in series to the push-button, in order for the FW to be able to use the LED indicator independently of the  push-button state (because without R2, when the push-button is ON the Q3 B-E junction limits the LED anode voltage to ~0.7V only).
- The omission of the LCD backlight current limiting resistor and the LCD Vee bias trimmer, since both those LCD module requirements are handled internally by elements (resistors) added directly to the LCD module PCB.
- Finally, the addition of a BootLoader header port (J3) for faster and less hassle FW updates, for those who really enjoy messing with the firmware!

Here are the schematics and the PCB top and bottom layout views of my Component Tester implementation:
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 19, 2013, 03:00:55 am
You made me succumb to the temptation of ignoring your project and, finally, to build that relentless spare-time killing device*! :)

It's part of our secret world domination plan :-)

Quote
Kidding aside, please let me contribute a little something to this fine project, and feel free to use it at will. This will be a surprisingly accurate version of the Sleep_5ms/MilliSleep time delay functions you already make use of.

Thanks! The sleep function doesn't has to be very accurate at the moment, it's just used to wait for uncritical stuff and saving power. But in case we need a more accurate version I got some nice code now :-)

Quote
(*) Here are a few ideas that might be of some use for the project.
This is my hardware version of a single layer PCB, an easy one to be built at home, with the following modifications:
- Additional PCB space to host a 9V battery, for an autonomous and completely floating testing device.
- The use of the more accurate and flexible LP2950-5.0 LDO/reference, which eliminates the need for an external voltage reference diode.
- The addition of R2 in series to the push-button, in order for the FW to be able to use the LED indicator independently of the  push-button state (because without R2, when the push-button is ON the Q3 B-E junction limits the LED anode voltage to ~0.7V only).
- The omission of the LCD backlight current limiting resistor and the LCD Vee bias trimmer, since both those LCD module requirements are handled internally by elements (resistors) added directly to the LCD module PCB.
- Finally, the addition of a BootLoader header port (J3) for faster and less hassle FW updates, for those who really enjoy messing with the firmware!

I wouldn't choose the 7805/78L05 either, the MCP1702 works also really great (0,4%). We're very careful with changes to keep everything compatible. But you could create a zip file with the layout and some documentation for the SVN if you like.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on July 19, 2013, 03:16:24 am
It's part of our secret world domination plan :-)

Oh, please my dear friend, do not force me to reveal my own agenda by changing my avatar to this, below... :-)


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: vehf277 on August 19, 2013, 05:31:21 am
Hello,
Can this tester be used as in-circuit ESR meter?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 19, 2013, 09:31:58 pm
Can this tester be used as in-circuit ESR meter?

No, because the voltage used is higher than 0.7V.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on August 19, 2013, 10:00:25 pm
Few months ago I was working  on a monitor and checking some caps. I replace some bad caps and powered it up and then decided I needed to check the main cap on the power supply. Remove cap connected the tester and nothing, no power on.  I realized I did not short the cap before testing.

Pretty sure it took the controller out. So just bought another.
Question is this, is it worth taking the time to replace the chip and reprogram it?  I have no problem changing the chip. But the programming may be an issue.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 19, 2013, 10:23:06 pm
Few months ago I was working  on a monitor and checking some caps. I replace some bad caps and powered it up and then decided I needed to check the main cap on the power supply. Remove cap connected the tester and nothing, no power on.  I realized I did not short the cap before testing.

There's an official mod for discharging caps with higher voltages (based on a relay). IIRC it's in Karl-Heinz' documentation.

Quote
Pretty sure it took the controller out. So just bought another.
Question is this, is it worth taking the time to replace the chip and reprogram it?  I have no problem changing the chip. But the programming may be an issue.

Yes, any ISP capable programmer will do the job. If the tester you bought matches the reference design you don't even need to compile a matching firmware. Please see http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) for precompiled firmwares and the source code.

BTW: I'd recommend an ATmega328.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on August 19, 2013, 11:14:16 pm
Thanks,
i'll give it a go.
Title: Re: $20 LCR ESR Transistor checker project
Post by: vehf277 on August 20, 2013, 02:27:36 am
Can this tester be used as in-circuit ESR meter?

No, because the voltage used is higher than 0.7V.
Thank you very much.
It would be great if there is is a way to modify the tester as it can be in-circuit ESR meter cos it is abnormally big price for specialized ESR testers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on August 20, 2013, 03:57:24 am
You can, provided you are testing a circuit that won't be damaged by voltages over 0.7v
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on August 20, 2013, 04:24:31 am
It is not only damage. Voltage bigger than 0.7 can turn things on and the reading wont be reliable.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 20, 2013, 05:21:17 am
Thank you very much.
It would be great if there is is a way to modify the tester as it can be in-circuit ESR meter cos it is abnormally big price for specialized ESR testers.

You're welcome! An in-circuit ESR meter would require a special design for low voltages and that would break the hardware-software compatibility we have. But there are a some circuits for dedicated ESR meters, please see http://www.eevblog.com/forum/beginners/esr-meter-circuit/ (http://www.eevblog.com/forum/beginners/esr-meter-circuit/).
Title: Re: $20 LCR ESR Transistor checker project
Post by: vehf277 on August 20, 2013, 07:41:44 am

You're welcome! An in-circuit ESR meter would require a special design for low voltages and that would break the hardware-software compatibility we have. But there are a some circuits for dedicated ESR meters, please see http://www.eevblog.com/forum/beginners/esr-meter-circuit/ (http://www.eevblog.com/forum/beginners/esr-meter-circuit/).
I know that URL. I spent a lot of time trying to find a good device for small money and I thought I've done but to my surprise I missed. Thank you very much anyway :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on August 20, 2013, 11:39:34 am
To prevent damage I wonder if a relay could be installed that shorts the test pins or maybe a button that you must hold down during the test. When you let go, it shorts the pins.

The relay could be normally closed but then goes open when a test is running, then closes again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 20, 2013, 09:35:45 pm
To prevent damage I wonder if a relay could be installed that shorts the test pins or maybe a button that you must hold down during the test. When you let go, it shorts the pins.

The relay could be normally closed but then goes open when a test is running, then closes again.

You're not the first one with that idea :-) Currently there are two moifications supported by Karl-Heinz' firmware. The first one is a relay based discharger for caps (voltage > 5V) and a zener test with a higher voltage (DC-DC converter based). Both are described in the documentation IIRC. And the third mod is a PWM driven backlight control (see my schematics in the SVN).
Title: Re: $20 LCR ESR Transistor checker project
Post by: noidea on September 18, 2013, 04:22:56 pm
Hi All
I had just started researching about how to create an electronic component tester using a microcontroller, and found the link to these devices as well as the original which suggest that somebody has already invented the wheel for me.
I was wondering if there was much difference between the various ones available on fleabay at the moment, can anyone make any recommendations as to which ones/sellers are the most up to date?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 19, 2013, 12:06:11 am
I had just started researching about how to create an electronic component tester using a microcontroller, and found the link to these devices as well as the original which suggest that somebody has already invented the wheel for me.
I was wondering if there was much difference between the various ones available on fleabay at the moment, can anyone make any recommendations as to which ones/sellers are the most up to date?

Actually you can buy any clone since they are all based on the same circuit. But most need a little fix as described in the official documentation. AFAIK there is no clone at ebay that includes all hardware extensions. Please see http://www.mikrocontroller.net/svnbrowser/transistortester/ (http://www.mikrocontroller.net/svnbrowser/transistortester/) for the documentation (English and German) and firmware updates.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bench2013 on September 19, 2013, 12:42:02 pm
Hi,

this thread looks awesome. I build one of these based on Markus F. (2009) very early design (ATMEGA8/48). It serves me well. I think time has move on, may be I should upgrade. Just wonder which controller does this Chinese clone comes with? Cheapo AMEGA8 or they put in more expensive 128/328? Always a dilemma, to build or to buy?

 :-+

Keep up the good work.

Ben
Title: Re: $20 LCR ESR Transistor checker project
Post by: toli on September 19, 2013, 03:42:26 pm
I got mine a couple of days ago, ver 2.4. The fw is 1.05, and the IC is the ATMEGA168. They didn't even scrub that off:
https://dl.dropboxusercontent.com/u/37472979/IMG_0137.JPG

I just did the bare minimum by removing the zener (which measured 2.03V instead of 2.5V), and adding 2 decoupling caps on the ATMEGA, I didn't do any other mods, I'm less concerned with battery life as with my amount of use the battery with lose most of its charge by self-discharge anyway :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: noidea on September 19, 2013, 04:13:24 pm
I got mine a couple of days ago, ver 2.4. The fw is 1.05, and the IC is the ATMEGA168. They didn't even scrub that off:

Thanks I have just spotted one that looks exactly the same as that based on the pcb markings.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 19, 2013, 09:24:11 pm
this thread looks awesome. I build one of these based on Markus F. (2009) very early design (ATMEGA8/48). It serves me well. I think time has move on, may be I should upgrade. Just wonder which controller does this Chinese clone comes with? Cheapo AMEGA8 or they put in more expensive 128/328? Always a dilemma, to build or to buy?

The clones we know about all got an ATmega168 but the 16k flash memory isn't enough to support all current firmware features. So I recommend to go for the ATmega328 (either replace the clone's 168 or build the tester yourself).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 19, 2013, 09:30:14 pm
I got mine a couple of days ago, ver 2.4. The fw is 1.05, and the IC is the ATMEGA168. They didn't even scrub that off:
https://dl.dropboxusercontent.com/u/37472979/IMG_0137.JPG

Yep, that's one of the common clones. But the firmware is a tad old by now. Karl-Heinz' current version is 1.08k and mine is 1.09m (no ESR, no hardware extensions, but a PWM tool).
Title: Re: $20 LCR ESR Transistor checker project
Post by: jav on September 19, 2013, 10:43:03 pm
I got mine a couple of days ago, ver 2.4. The fw is 1.05, and the IC is the ATMEGA168. They didn't even scrub that off:
https://dl.dropboxusercontent.com/u/37472979/IMG_0137.JPG

Yep, that's one of the common clones. But the firmware is a tad old by now. Karl-Heinz' current version is 1.08k and mine is 1.09m (no ESR, no hardware extensions, but a PWM tool).
That's the one I've also bought, but I made some changes to it: Apart from the decoupling capacitors, I changed the voltage regulator and the CPU (ATmega328), added a voltage reference (instead of the zener) and a 8 MHz crystal. Then I changed to the 1.08k version and works great.

The software is awesome! Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: noidea on September 19, 2013, 10:50:00 pm
Yep, that's one of the common clones. But the firmware is a tad old by now. Karl-Heinz' current version is 1.08k and mine is 1.09m (no ESR, no hardware extensions, but a PWM tool).
[/quote]
I guess asking the seller to tell you what the version is the only way to find out.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 20, 2013, 02:17:20 am
I guess asking the seller to tell you what the version is the only way to find out.

It's not that important ;-) Add an ISP header and flash the current firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: krivx on September 20, 2013, 03:20:50 am
Could someone provide a link to to the auction? I can only find the older DIP clone on ebay.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jav on September 20, 2013, 08:15:09 am
Could someone provide a link to to the auction? I can only find the older DIP clone on ebay.
This is the one I bought. Even if in the pictures comes with the crystal installed, the ones I got don't have it.

www.ebay.com/itm/330917635775 (http://www.ebay.com/itm/330917635775)
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on September 20, 2013, 09:06:58 am
Do a search on ebay for "transistor tester esr" and you'll find lots of sellers. I would chose one with back-lit LCD. There also many revisions of the board I think that there are revisions 2.1, 2.2, 2.3, and 2.4 on the SMD version. I don't know what the difference between the revisions are. I'm sure that it is discussed on the forum:
http://www.mikrocontroller.net/topic/248078. (http://www.mikrocontroller.net/topic/248078.)

 
Title: Re: $20 LCR ESR Transistor checker project
Post by: noidea on September 20, 2013, 11:42:39 am
Could someone provide a link to to the auction? I can only find the older DIP clone on ebay.
I'm in Australia and are looking at this one
http://www.ebay.com.au/itm/290949358387 (http://www.ebay.com.au/itm/290949358387)

They also have a DIP version as well that's cheaper
http://www.ebay.com.au/itm/300937438443 (http://www.ebay.com.au/itm/300937438443)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 20, 2013, 11:52:33 am
Do a search on ebay for "transistor tester esr" and you'll find lots of sellers. I would chose one with back-lit LCD. There also many revisions of the board I think that there are revisions 2.1, 2.2, 2.3, and 2.4 on the SMD version. I don't know what the difference between the revisions are. I'm sure that it is discussed on the forum:
http://www.mikrocontroller.net/topic/248078. (http://www.mikrocontroller.net/topic/248078.)
Problem with the url it has a period at the end so returns a 404 error.

The issue with all of these on fleabay is that they do not say what version they are for the ones I quickly scanned over.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 20, 2013, 09:19:17 pm
Problem with the url it has a period at the end so returns a 404 error.

Please try http://www.mikrocontroller.net/topic/248078 (http://www.mikrocontroller.net/topic/248078) :-)

That trailing dot is special (annoying) feature of this forum's software.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 21, 2013, 02:23:06 am
Problem with the url it has a period at the end so returns a 404 error.

Please try http://www.mikrocontroller.net/topic/248078 (http://www.mikrocontroller.net/topic/248078) :-)

That trailing dot is special (annoying) feature of this forum's software.
Aye.

I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?
Title: Re: $20 LCR ESR Transistor checker project
Post by: toli on September 21, 2013, 02:47:22 am
I also got a little lost with the different revision of the fw. What was added/removed in each revision? Is the HW exactly the same in all revisions?

I guess its all somewhere in the documentation, but a quick look only gave me partial answers. Never mind, I'm very happy with it, and fact I ordered one from eBay and spent no time in building it myself is even better as I don't have the time right now :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 21, 2013, 05:33:04 am
I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?

You'll find a modified firmware for the Arduino at http://www.pighixxx.com/lavori/ardutester/ (http://www.pighixxx.com/lavori/ardutester/) (includes also a shield).
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 21, 2013, 05:45:07 am
I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?

You'll find a modified firmware for the Arduino at http://www.pighixxx.com/lavori/ardutester/ (http://www.pighixxx.com/lavori/ardutester/) (includes also a shield).
So, best to buy one of those off of ebay then?  Seems less costly but lacks freedom too I think.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 21, 2013, 06:06:14 am
I also got a little lost with the different revision of the fw. What was added/removed in each revision? Is the HW exactly the same in all revisions?

The firmware got additional features (can't remember them all :-) and tons of improvements. We keep everything compatible with the basic design, i.e. all hardware extensions are optional. If you got a very old hardware (Markus F.'s original design) you might need to apply some changes.
Title: Re: $20 LCR ESR Transistor checker project
Post by: toli on September 21, 2013, 06:12:12 am
The need to go and check is exactly why I don't do that, who's got the time?!  :(

Anyway, I'm happy with my unit. fw 1.05 might be a bit old, but it does what I need it to do. Resistors and capacitors are measured quite well with results no too far from my U1253A (actually very close to identical). Diodes Vf also about the same as I got at 6mA measurement in a test rig I once built (it had a temp chamber for temp-co measurement, and 6mA was used as this was the expected in circuit operation). I've measured some JFET's, BJT's, MOSFET's, everything seems to be good. Inductors are the only thing I can't confirm as I don't have an inductance meter (and the old time-constant measurement with the scope is too time consuming at the moment), but the values seem to be close to what's printed on the part so I guess its good as well.

I really only need it for ESR (to know if a cap is good or bad,  the exact value is of no interest to me), for inductance (again, precision isn't very important for my current needs), and for transistor matching - it can do all this so its well worth the price.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 21, 2013, 06:26:31 am
So, best to buy one of those off of ebay then?  Seems less costly but lacks freedom too I think.

The Transistor Tester isn't a development platform, it's a tool designed for a specific purpose. The Arduino lacks the complete power management which the Transistor Tester got (optimized for battery usage).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 21, 2013, 06:39:06 am
I really only need it for ESR (to know if a cap is good or bad,  the exact value is of no interest to me), for inductance (again, precision isn't very important for my current needs), and for transistor matching - it can do all this so its well worth the price.

1.07k got an improved ESR measurement and 1.08k considers the leakage current of a BJT for hFE and fixes a problem with Germanium BJTs.
Title: Re: $20 LCR ESR Transistor checker project
Post by: toli on September 21, 2013, 06:40:40 am
Damn! Now I should probably install 1.08k :)

Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on September 26, 2013, 05:38:55 pm
The Arduino lacks the complete power management which the Transistor Tester got (optimized for battery usage).

I'd say 'partly'. You can still put a simple switch between the battery and the arduino.

Self-Power-Off won't work this way, but the sleepmodes can still be used. So it's more a question of convenience than a real problem.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 26, 2013, 10:07:29 pm
The Arduino lacks the complete power management which the Transistor Tester got (optimized for battery usage).

I'd say 'partly'. You can still put a simple switch between the battery and the arduino.

Self-Power-Off won't work this way, but the sleepmodes can still be used. So it's more a question of convenience than a real problem.

It's not impossible :-) Please see http://www.pighixxx.com/lavori/ardutester/ (http://www.pighixxx.com/lavori/ardutester/) for an Arduino version. But there are several differences due to the different hardware designs, starting with the voltage regulator (MCP1702 has a typical voltage tolerance of 0.4% at room temperature). And the dedicated hardware is less expensive than an Arduino Uno.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 30, 2013, 12:30:56 pm
The Arduino lacks the complete power management which the Transistor Tester got (optimized for battery usage).

I'd say 'partly'. You can still put a simple switch between the battery and the arduino.

Self-Power-Off won't work this way, but the sleepmodes can still be used. So it's more a question of convenience than a real problem.

It's not impossible :-) Please see http://www.pighixxx.com/lavori/ardutester/ (http://www.pighixxx.com/lavori/ardutester/) for an Arduino version. But there are several differences due to the different hardware designs, starting with the voltage regulator (MCP1702 has a typical voltage tolerance of 0.4% at room temperature). And the dedicated hardware is less expensive than an Arduino Uno.
SainSmart Mega2560 R3 ATmega2560-16AU + ATMEGA16U2 + USB Cable For Arduino 2013 http://www.ebay.com/itm/271187169712?ss (http://www.ebay.com/itm/271187169712?ss)
$17.99 delivered and while it does not have a screen I was wondering if that would work as good and at least I could update its firmware very easily but the ready made ones do not have that capability that I could see.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 30, 2013, 07:22:10 pm
I sent this one guy a message asking what version was his running and he sent me back
Quote
Dear friend,

Really so sorry. I do not know what the problem is. I hope you can understand
He doesn't even know what a version is be it either hardware or software and other ones did show a version number of 2.xx on the main board but they were hard to read at the angle of the picture.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bilko on September 30, 2013, 07:58:55 pm
I really only need it for ESR (to know if a cap is good or bad,  the exact value is of no interest to me), for inductance (again, precision isn't very important for my current needs), and for transistor matching - it can do all this so its well worth the price.

1.07k got an improved ESR measurement and 1.08k considers the leakage current of a BJT for hFE and fixes a problem with Germanium BJTs.

I couldn't see 1.08k, has this been posted somewhere else ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 30, 2013, 10:51:03 pm
I couldn't see 1.08k, has this been posted somewhere else ?

1.08k is the current version and the current version is located at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) :-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 30, 2013, 11:06:53 pm
SainSmart Mega2560 R3 ATmega2560-16AU + ATMEGA16U2 + USB Cable For Arduino 2013 http://www.ebay.com/itm/271187169712?ss (http://www.ebay.com/itm/271187169712?ss)
$17.99 delivered and while it does not have a screen I was wondering if that would work as good and at least I could update its firmware very easily but the ready made ones do not have that capability that I could see.

I've found following tester clones including the LCD module:
- www.ebay.com/itm/131000917393?ss (http://www.ebay.com/itm/131000917393?ss) $18.55 + $ 0.99 shipping
- www.ebay.com/itm/271267317113?ss (http://www.ebay.com/itm/271267317113?ss) $12.89 + free shipping (no pads for ISP)

For most clones you just need to solder in a pin header for the ISP.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on September 30, 2013, 11:23:27 pm
SainSmart Mega2560 R3 ATmega2560-16AU + ATMEGA16U2 + USB Cable For Arduino 2013 http://www.ebay.com/itm/271187169712?ss (http://www.ebay.com/itm/271187169712?ss)
$17.99 delivered and while it does not have a screen I was wondering if that would work as good and at least I could update its firmware very easily but the ready made ones do not have that capability that I could see.

I've found following tester clones including the LCD module:
- www.ebay.com/itm/131000917393?ss (http://www.ebay.com/itm/131000917393?ss) $18.55 + $ 0.99 shipping
- www.ebay.com/itm/271267317113?ss (http://www.ebay.com/itm/271267317113?ss) $12.89 + free shipping (no pads for ISP)

For most clones you just need to solder in a pin header for the ISP.
What is an ISP? I know Internet Service Provider but that isn't something you can solder on a PCB.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 12:02:09 am
What is an ISP? I know Internet Service Provider but that isn't something you can solder on a PCB.
In System Programming, aka ISP, is one of the various hardware/software layers protocols for the programming of the ATMEL AVR line of microcontrollers, among the Bootloader programming, JTAG programming, HVPP (High Voltage Parallel Programming), HVSP (High Voltage Serial Programming), etc., all of which protocols are extensively documented in every AVR datasheets.

So, yes, it is perfectly feasible to solder an ISP header on a PCB. For example, here (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg263699/#msg263699) you can see J3, which is the Bootloader (with the RxD/TxD/GND lines) / Power (with the GND/Vdd lines) Header.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: bilko on October 01, 2013, 12:11:09 am
I couldn't see 1.08k, has this been posted somewhere else ?

1.08k is the current version and the current version is located at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) :-)
Thanks for that :)
I suspected that, however I just wanted to check as I could not see any version info in the trunk, the readme files is for version 1.06k?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 12:22:50 am
What is an ISP? I know Internet Service Provider but that isn't something you can solder on a PCB.
In System Programming, aka ISP, is one of the various hardware/software layers protocols for the programming of the ATMEL AVR line of microcontrollers, among the Bootloader programming, JTAG programming, HVPP (High Voltage Parallel Programming), HVSP (High Voltage Serial Programming), etc., all of which protocols are extensively documented in every AVR datasheets.

So, yes, it is perfectly feasible to solder an ISP header on a PCB. For example, here (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg263699/#msg263699) you can see J3, which is the Bootloader (with the RxD/TxD/GND lines) / Power (with the GND/Vdd lines) Header.


-George
Which is the ISP header?  I don't own an Arduino but I want one of these that are the most up to date but the sellers are worthless as they have zero knowledge.  It is One Hung Low at its best.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 12:36:20 am
I have never used the Arduino platform, so I could not answer your specific question. Neither can I speak for the various e-bay implementations; as you said it yourself, these e-bay people are sellers and they probably know nothing more that the price of their merchandise and their commission!

Now, in the example I have linked to in my previous message, I am using the Bootloader for programming, so there is no ISP header in the proposed PCB.

The ATMEL AVR ISP Header is a 6-pin link between the programmer and the target chip. This is the ATMEL AVR910 In-System Programming (http://www.atmel.com/images/doc0943.pdf) application note, describing a low cost AVR ISP programmer that uses the hardware SPI module the target chips have embedded for that purpose.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 01, 2013, 03:11:56 am
the readme files is for version 1.06k?

You'll find the current complete documentation (ttester.pdf) at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) (unfortunately you have to download the whole directory).
Title: Re: $20 LCR ESR Transistor checker project
Post by: bilko on October 01, 2013, 03:56:46 am
the readme files is for version 1.06k?

You'll find the current complete documentation (ttester.pdf) at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) (unfortunately you have to download the whole directory).

Thanks, that's great !
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 06:30:12 am
The guy wrote me back and his response about having the revision number was "Because we are not suppliers, hope you can understand".

Utterly hopeless.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 01, 2013, 06:45:26 am
The guy wrote me back and his response about having the revision number was "Because we are not suppliers, hope you can understand".

Utterly hopeless.

Don't worry! Solder in an ISP pin header and get an ISP programmer 8)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 07:41:46 am
The guy wrote me back and his response about having the revision number was "Because we are not suppliers, hope you can understand".

Utterly hopeless.

Don't worry! Solder in an ISP pin header and get an ISP programmer 8)
Which one of these http://tinyurl.com/mt3ao3t (http://tinyurl.com/mt3ao3t)  and where do I get a header from?  Might just get that one that has it already but that is a HUGE price difference imo between the two I was linked.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 07:47:52 am
What is an ISP? I know Internet Service Provider but that isn't something you can solder on a PCB.
In System Programming, aka ISP, is one of the various hardware/software layers protocols for the programming of the ATMEL AVR line of microcontrollers, among the Bootloader programming, JTAG programming, HVPP (High Voltage Parallel Programming), HVSP (High Voltage Serial Programming), etc., all of which protocols are extensively documented in every AVR datasheets.

So, yes, it is perfectly feasible to solder an ISP header on a PCB. For example, here (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg263699/#msg263699) you can see J3, which is the Bootloader (with the RxD/TxD/GND lines) / Power (with the GND/Vdd lines) Header.


-George
Which is the ISP header?  I don't own an Arduino but I want one of these that are the most up to date but the sellers are worthless as they have zero knowledge.  It is One Hung Low at its best.
www.ebay.com/itm/131000917393?ss (http://www.ebay.com/itm/131000917393?ss)
I take it that the last picture of the three at the left hand side those 10 holes is for a non existent, but easily added, header?

10 - 10 pin (2x5) headers for $1.85 http://tinyurl.com/kyk7kwk (http://tinyurl.com/kyk7kwk) delivered.

One thing I am noticing is that the LCD shield will never fit once the header is soldered in.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 08:20:48 am
Yes, it seems that it must be a socket for the 10-pin AVR ISP header.

Be careful with the ISP polarity though!
This is the pinout for the standard 6-pin and 10-pin AVR ISP headers:

(http://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Isp_headers.svg/220px-Isp_headers.svg.png)


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 08:23:26 am
Yes, it seems that it must be a socket for the 10-pin AVR ISP header.

Be careful with the ISP polarity though!
This is the pinout for the standard 6-pin and 10-pin AVR ISP headers:

(http://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Isp_headers.svg/220px-Isp_headers.svg.png)


-George
It looks like a 10 (2x5) header but I see no indication of which is pin 1 on that board.  As I said above I am a bit doubtful that the LCD shield will fit once an ISP header is added as the header is taller, I think, than is the LCD header it looks like.

After looking at the board and those pinouts of the ISP headers it appears that the header will face down in the picture as the bottom two holes the first hole to the left of the picture appears to be going to Vcc.

It looks like the RST pin is not connected.(http://ecx.images-amazon.com/images/I/51UcGCMY8sL.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 09:05:46 am
Quote
After looking at the board and those pinouts of the ISP headers it appears that the header will face down in the picture as the bottom two holes the first hole to the left of the picture appears to be going to Vcc.
This is probably right.

Quote
It looks like the RST pin is not connected.
Neither the four ground pins do! That is because this is a dual layer PCB, with the 'missing' traces existing at the other, opposite layer.

Regarding the LCD PCB, I am afraid that you are right: The ISP header pins are of the same height as the LCD header pins, and the ISP pins might hit (and short) the LCD resistors. Of course, you could trim the ISP pins height (push them gently, no more than a couple of millimetres, down through their plastic base assembly, and after soldering the header cut their excessive portions) and insulate the LCD PCB area that faces the ISP header.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: senso on October 01, 2013, 09:25:31 am
Or solder female headers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 09:48:13 am
Or a 5*2 pin 90° Degree header (http://www.google.com/search?um=1&newwindow=1&hl=en&tbm=isch&q=90%C2%B0+Degree+pin+header).


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 12:01:47 pm
Or a 5*2 pin 90° Degree header (http://www.google.com/search?um=1&newwindow=1&hl=en&tbm=isch&q=90%C2%B0+Degree+pin+header).


-George
Yes, that is exactly what I was thinking but couldn't find any on Ebay so my search will continue. http://www.ebay.com/itm/Dual-Rows-2-54mm-Pitch-10Pins-90-Degree-Angle-IDC-Pin-Headers-5-Pcs-/321218266576?pt=LH_DefaultDomain_0&hash=item4aca19c5d0 (http://www.ebay.com/itm/Dual-Rows-2-54mm-Pitch-10Pins-90-Degree-Angle-IDC-Pin-Headers-5-Pcs-/321218266576?pt=LH_DefaultDomain_0&hash=item4aca19c5d0)

Now, once I have that soldered in then I get an AVR (I guess the ones I showed are alright?) I just grab a sketch and upload it to it?
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 01:01:01 pm
Yes, you will need an AVR ISP programmer to upload the new firmware, which is a *.HEX file.

BUT, things are a little more complicated than that because the latest TransistorTester revisions have extended functionality and require the mega328 AVR microcontroller, which has 32 kB of FLASH memory. Most (if not all) of the chinese TransistorTester knock-offs have the cheaper and smaller mega168 that has 16 kB of FLASH memory only or, even worse, the even cheaper mega88 with 8 kB of memory or the older mega8. The latest firmware will only fit in 32 kB memory, if you want it to have full functionality; or else, you will have to recompile the project with some functions disabled (read the project files, I do not remember specific details) in order for the firmware to fit in FLASH memory sizes of less than 32 kB.

So, with the ISP programmer, you will firstly need to check which microcontroller is on board (since most of these knock-offs usually have their chip identification marks erased). If the programmer identifies the microcontroller to be a mega328, you will just have to load it with the latest firmware and you are done. If the chip is identified as a mega168/mega88/mega8, you will also need to change it with a mega328.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 01:20:31 pm
Yes, you will need an AVR ISP programmer to upload the new firmware, which is a *.HEX file.

BUT, things are a little more complicated than that because the latest TransistorTester revisions have extended functionality and require the mega328 AVR microcontroller, which has 32 kB of FLASH memory. Most (if not all) of the chinese TransistorTester knock-offs have the cheaper and smaller mega168 that has 16 kB of FLASH memory only or, even worse, the even cheaper mega88 with 8 kB of memory or the older mega8. The latest firmware will only fit in 32 kB memory, if you want it to have full functionality; or else, you will have to recompile the project with some functions disabled (read the project files, I do not remember specific details) in order for the firmware to fit in FLASH memory sizes of less than 32 kB.

So, with the ISP programmer, you will firstly need to check which microcontroller is on board (since most of these knock-offs usually have their chip identification marks erased). If the programmer identifies the microcontroller to be a mega328, you will just have to load it with the latest firmware and you are done. If the chip is identified as a mega168/mega88/mega8, you will also need to change it with a mega328.


-George
The sellers are just too stupid to help and I know I don't do SMT so now I just need to find someone with some self respect and decency and BRAINS who tell you what is on it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 03:15:35 pm
Well, you can let the sellers remain ignorant or non-helping, and use your eyes, knowledge and good judgment instead!

After a brief search I found several e-bay Testers with a PDIP chip on board, which is most easy to be changed if it is not an m328.

What to look for in the pictures of the Testers that you will find:
- There should be a crystal on board, for the time-depended measurements accuracy.
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.
- This is not critical but there should be a golden-plated socket for the chip, for better contact with the chip pins. If there is a cheap socket you can either leave it as is or change it with a better one.
- There should be an ISP header or socket. If there is not, an ISP header can easily be fitted in an unpopulated PCB area with a hot-glue gun, and be connected through cables directly soldered to the four ISP lines of the chip socket pins and to the GND and Vcc lines.
- Make sure that the seller will ship to you *exactly* what you have ordered.

This is not a rule but, a better looking and more pleasing to the eyes PCB layout and construction is usually made by a better designer.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 03:40:48 pm
Well, you can let the sellers remain ignorant or non-helping, and use your eyes, knowledge and good judgment instead!

After a brief search I found several e-bay Testers with a PDIP chip on board, which is most easy to be changed if it is not an m328.

What to look for in the pictures of the Testers that you will find:
- There should be a crystal on board, for the time-depended measurements accuracy.
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.
- This is not critical but there should be a golden-plated socket for the chip, for better contact with the chip pins. If there is a cheap socket you can either leave it as is or change it with a better one.
- There should be an ISP header or socket. If there is not, an ISP header can easily be fitted in an unpopulated PCB area with a hot-glue gun, and be connected through cables directly soldered to the four ISP lines of the chip socket pins and to the GND and Vcc lines.
- Make sure that the seller will ship to you *exactly* what you have ordered.

This is not a rule but, a better looking and more pleasing to the eyes PCB layout and construction is usually made by a better designer.


-George
Good things to look for but I am finding most of these sales are from the same handful of sellers that are selling a ton of them all at once so it looks like there is more than there really is.  What I do is not even look at the seller's name and scan down to the pics and descriptions and within 10 secs I can tell it is the same as a previous one I looked at.

You know I am beginning to wonder how many Chinese sellers Ebay really has as this is not the first product that seems like a ton of sellers with all sorts of different prices and even with some make offers (they never work for me) but they are all from the same handful of sellers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 01, 2013, 04:56:30 pm
1. Looks like one of the nicer ones.  Be interesting to see that board revision number.
http://www.ebay.com/itm/151124228042 (http://www.ebay.com/itm/151124228042)

2. Similar but blue screen
http://www.ebay.com/itm/181225081033 (http://www.ebay.com/itm/181225081033)

3. Zif socketed one
http://www.ebay.com/itm/231056057317 (http://www.ebay.com/itm/231056057317)

4. Looks like a later board revision here pity no gutshot
http://www.ebay.com/itm/121184647718 (http://www.ebay.com/itm/121184647718)

5. Battery powered, USB
http://www.ebay.com/itm/390589763450 (http://www.ebay.com/itm/390589763450)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 05:06:02 pm
Notice all of those green boards are from the same people and are V2.2/2.3 but that red board is a bit intriguing though one of them (I forgot which one) had what I thought very lousy results as they showed what the value was and what it read.  Close but 10% close I think it was which is pretty bad (33uH read .03mH).
Title: Re: $20 LCR ESR Transistor checker project
Post by: Dark Prognosis on October 01, 2013, 05:52:03 pm
Or a 5*2 pin 90° Degree header (http://www.google.com/search?um=1&newwindow=1&hl=en&tbm=isch&q=90%C2%B0+Degree+pin+header).


-George
I did a little more digging via the spec sheet as I was noticing something odd and I was correct.  The height is 9.1mm of a standard 10 (5x2) IDC connector and the height of the same connector at a 90 degree angle is 9.0mm.  So, the bloody thing is as deep as it is tall. :/
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 06:31:35 pm
Looks like one of the nicer ones.
I could not recommend something for which I do not have the precise specifications. This is what I can see and deduce from the pictures, with the devices numbered in the order they are presented:

- Numbers 3 and 4 seem to be more robust because they have their LCD PCB secured on the mainboard with bolts and spacers.
- Numbers 1, 2, 5 and probably 4 come with unknown chip (probably an m168) in TQFP package, and with ISP socket.
- Numbers 1 and 5 do not seem to have a crystal time-base, which is required for the time-depended measurements accuracy.
- Number 5 with the LiPo battery has an on-board DC-DC converter, that might increase electrical noise.
- Number 4 is called 'M8 transistor tester' (because of the mega8 it possibly has on board?) Is the chip in PDIP or in TQFP package? Does it have a crystal time-base?
- Number 3 has a mega328 in PDIP socketed on board and runs a firmware that seems to be more recent than the other ones. The m328 can be removed from the socket and be updated with an AVR ISP and a breadboard.

[...] So, the bloody thing is as deep as it is tall.
So, trimming the pins and insulating the LCD PCB might work.
But, what the reprogramming is good for if the chip is not an m328?

EDIT: By the way, I should warn you to be careful with the AVR Fuses because a wrong setting can brick the chip and its revival can be from difficult (by the injection of an external clock) to painfull (by desoldering and HVPP with a special HV programmer, like the ATAVRDRAGON).


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: darrylp on October 01, 2013, 07:20:35 pm
Here is my socket, no problems with clearance.

(http://img.tapatalk.com/d/13/10/01/pazuje8u.jpg)

(http://img.tapatalk.com/d/13/10/01/hutubaze.jpg)


--
 Darryl

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 01, 2013, 10:35:29 pm
- They should have 1% tolerant resistors. There are boards with 5% resistors; this is not good for accuracy but the critical resistors can easily be changed with 1% ones.

The 680 and 470k Ohms resistors for the test pins should have a 0.1% tolerance. Or you could select matched ones and update the default values in config.h.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 01, 2013, 10:58:38 pm
We are in total agreement, dear Markus.

But, I was talking about Through-Hole resistors. It is almost next to impossible to find through-hole resistors of a better than 1.0% tolerance in the retail market (at least, over here, in Greece). On the other hand, SMT resistor chips of 0.1% (or 0.05% or even 0.01%) tolerance is not only feasible to find but it is also accessible and obtainable at a reasonable price (in Digi-Key/Mouser/etc.).


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 01, 2013, 11:52:27 pm
But, I was talking about Through-Hole resistors. It is almost next to impossible to find through-hole resistors of a better than 1.0% tolerance in the retail market (at least, over here, in Greece). On the other hand, SMT resistor chips of 0.1% (or 0.05% or even 0.01%) tolerance is not only feasible to find but it is also accessible and obtainable at a reasonable price (in Digi-Key/Mouser/etc.).

Reichelt sells 0.1% through-hole resistors (Yageo) for € 0.16 each in case if someone has problems with finding any and lives in the EU. Otherwise you could create through-hole resistors by adding some wire to the SMT resistors :-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 02, 2013, 12:33:03 am
Reichelt: 680 Ohm (http://www.reichelt.com/Metal-0-1-100-Ohm-910-Ohm/MPR-680/3/index.html?&ACTION=3&LA=2&ARTICLE=13051&GROUPID=3103&artnr=MPR+680)/470 kOhm (http://www.reichelt.com/Metal-0-1-100-k-Ohm-1-00-M-Ohm/MPR-470K/3/index.html?&ACTION=3&LA=2&ARTICLE=12984&GROUPID=3105&artnr=MPR+470K)! This is interesting, thank you!
I did not know that, neither did I do any search in the wider EU market for such components, since I have learned how much it hurts to be purchasing very low quantities from the known component warehouses. Now I know better, thanks to you!

Well, what I did with what I was able to find locally, was to get 10 x 1% resistors of each (critical) value and to use the three of each value that I could match with the ohmmeter as close as possible to each other, updating at the same time the project configuration file resistor values with the actually measured ones. The result was not bad, giving me almost 0.1% match between the measurement readings of the same component that I tested using all the three combinations of the test-point pairs (TP1 to TP2, TP2 to TP3 and TP3 to TP1).


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: TonyGreene on October 07, 2013, 12:37:22 pm
I bought a couple of these units off of Ebay - SamLove from China.  These units use the ATMEGA328P-PU in the long DIP form.  They do not have the 2.5V voltage reference on Pin 27, but they do have the 8 Mhz crystal and the bypass caps.

I did a test, right out of the box, and here is the results, with no calibration;

47pF 5% Mica         55pF            52pF
150pF 5% Mica         162pF            161pF
300pF 10% Mica         323pF            322pF
470pF 10% Mica         470pF            459pF
560pF 5% Mica         574pF            571pF
3000pf 2% Mica         3062pF         3040pF
4300pF 1% Mica         4392pF         4369pF
8200pf 1% Mica         8394pF         8347pF
11000pf 5% Mica         10.67nF         10.62nF
17000pF 2% Mica         17.27nF         17.17nF
.00604uF 3%            6060pF         6025pF
.00301uF 3%            3151pF         3136pF
.0243uF 3%            25.09nF         24.62nF
.0478uF 3%            48.31nF         47.44nF
.075uF 1%            75.98nF         75.5nF
.0768uF 1%            78.14nF         77.70nF
.183uF 2%            185.1nF 1.6o         182.2nF 1.2o
1.0uF 10%            1112nF .42o         1106nF .42o
1uF Tant            1051nF 4.3o .5%      1038nF 5.7o .6%
2uF Mylar            2216nF .25o         2203nF .24o
3uF Mylar            3143nF .22o         3124nF .21o
4uF Mylar            4151nF .22o         4127nF .21o
10uF Tant            diode 3.57V 11.5uF      diode 3.92V 11.2uF
1uF Mil Glass            990.1nF .91o .1%      979.3nF .89o .1%
100uF Electro            100.2uF .52o .4%      97.43uF .51o .5%
234uf 10% NP Aluminum Electro   230.9uF .23ohm 1.0%   223.7uF .21o 1.2%
470uF Electro            544.ouF .24o .5%      529.8uF .34o .7%
2000uF Electro         2154uF .2o .6%      2096uF .18o .6%
3300uF            3318uF .19o 1.5%      3249uF .21o 1.3%
8000uF Electro         8999uF .22o .6%      8779uF .20o .6%
10,000uF Electro         11.67mF .20o 1.6%      11.38mF .16o 1.6%

10uH               .5o .01mH         .4o .01mH
100uH               1.5o   .09mH         1.6o .09mH
2.5mH               20.0o   2.64mH      19.7o 2.61mH
30mH               3.1o 29.8mH         3.2o 30.1mH
44mH               55.7o 40.8mH         56.7o 40.5mH
50mH               46.7o 50.8mH         47.5o 50.8mH
120mH            158.8o 122mH      159.6o 123mH
250mH            32.8o 248mH         33.5o 247mH
720mH            44.3o 703mH         45.0o 701mH
2.3H               62.3o 7.46H         63.5o 7.75H

zero ohm .1% decade         .28o            .27o
.5 ohm decade         .66o            .79o
1 ohm decade            1.28o            1.31o
5 ohm decade            5.34o            5.51o
10 ohm decade         10.5o            10.7o
50 ohm decade         50.8o            51.7o
100 ohm decade         101.2o            103.1o
500 ohm decade         498.8o            499.2o
1K decade            1003o            1003o
5K decade            4957o            4888o
10K decade            9955o            9786o
40K decade            40.57K         41.30K

10K .1$ MF            9786o            9962o
162K .1% MF            161.8K         162.0K
300K .1% MF            300.2K         300.3K
499K .1% MF            499.2K         499.6K

100 ohm .05% WW         101.1o            102.9o
1K .01% WW            1003o            1003o
10K .01% WW         9955o            9788o
100K .01% WW         101.2K         103.0K
1M .01% WW            1002K            1002K
9M 1% WW            9215K            9032K

RS2761067 SCR 200V 6A      NPN transistor....
2N3440            B99 595mV         B100 663mV
2N3906            B190 674mV         B186 748mV
2N5415            B72 660mV         B70 659mV
IFR820 FET            N E MOS C958pf V+3.31V   c941pF 3.33V
MPF102 FET            N JFET 2.7mA gs 1.87   2.7mA gs1.89

1N4146            709mV 10pF         787mV 9pF
1N5400            604mV 84pF         642mV 82pF
1N6263            573mV 8pF         586mV 8pF
MBR10H100CT         363mV 363mV      369mV 369mV



Title: Re: $20 LCR ESR Transistor checker project
Post by: TonyGreene on October 07, 2013, 12:38:13 pm
Another picture close up

These units are nice for us older folks, who can't see like we use to, it will make sure the parts are in the right ballpark before stuffing our boards.

I do plan to add the 2.5 volt reference and put the units in a case.

I think, but not sure that the software in these units are either 1.07 or 1.08.  The seller never could answer the question.  I would be nice to put the version in the bootup screen.

(added; as suggested below, I did the cal and its loaded with V1.07)

Title: Re: $20 LCR ESR Transistor checker project
Post by: gtroc71 on October 07, 2013, 01:05:52 pm
Hey Tony, my tester displays the version at the end of the calibration process.
Don't know if that is just the version I have (105) but I assume it works with all  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 07, 2013, 11:48:21 pm
I did a test, right out of the box, and here is the results, with no calibration;

I strongly recommend to run the self-adjustment. It measures the resistance and capacitance of the probes (incl. the PCB), internal IO port resistance, offsets of the bandgap reference and analog comparator and so on. Those values/offsets are stored in the EEPROM and will be taken into account for all new measurements which will be more precise. Without the self-adjustment some default values are used and they might not match your tester very well.

Please run the self-adjustment, re-run your tests and compare the results. And you'll will see :-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: rastro on October 08, 2013, 10:07:34 am
Another picture close up

I do plan to add the 2.5 volt reference and put the units in a case.


Tony, I probably missed something what is the 2.5 volt reference you're referring to.  Is it a modification instead of internal 328 reference?
 
Title: Re: $20 LCR ESR Transistor checker project
Post by: TonyGreene on October 08, 2013, 01:07:23 pm
The 2.5V reference is discussed in chapter 2.1 and 2.4 of the V1.08 software, and maybe the same in previous versions.

Chapter 2.1 tells that an external voltage reference connected at pin PC4 can be used to check and calibrate the VCC voltage, but is not required for the basic operation of the Transistor/LCR tester.

Chapter 2.4 tells that sometimes with no connection to the pin, it may display unknown VCC voltage.  If this happens they recommend using a pullup resistor from the pin to VCC.  The pullup resistor keeps the processor from displaying the regulator output voltage.

The unit I received had no connection to pin 27.  I connected a 2.41K 0.5% resistor from the output of the +5 regulator to the cathode of the LM336Z-2.5 reference.  The anode of the reference is connected to ground.  Make a connection from the cathode of the reference to pin 27 of the ATmega328 and the unit will read the +5 volt regulator voltage.  And note this connection only works if you have the ATmega328 chip in the photo's I posted.  The connection is different depending on your ATmega328 chip package.

You don't need this, but its handy, you can run your battery all the way down until its starts affecting the +5 volt reference output.
Title: $20 LCR ESR Transistor checker project
Post by: Napalm2002 on October 09, 2013, 03:55:31 am
Bought one. Really like it and is definitely worth the few bucks that it costs.
Title: $20 LCR ESR Transistor checker project
Post by: Napalm2002 on October 09, 2013, 03:59:34 am
I was kicking around putting mine in an enclosure and putting leads on it. You did a nice job. Gonna have to get out the dremel tool and solder some stuff now
Title: Re: $20 LCR ESR Transistor checker project
Post by: TonyGreene on October 10, 2013, 11:22:34 am
Here is a test of one of my units, I call it serial number 1.  The unit is cased and self-calibrated.

Test start 10/9/2013 17:41 71.5F    12V Battery
Test End 10/9/2013 19:12  72.0F

LM395 Matched Pair Transistor   Side A       B=1.03K Uf=619mV   
Unit 1                               Side B      B=1.03K Uf=614mV

LM395                                    Side A      B=860  Uf=614mV
Unit 2                               Side B      B=870  Uf=609mV

2N3904            NPN      B=168  Uf=716mV
Tung-Sol ET-1         PNP      B=89  Uf=117mV
2N2222            NPN      B=170  Uf=665mV
2N2907A            PNP      B=161  Uf=628mV
2N3440            NPN      B=101  Uf=576mv
2N5415            PNP      B=62  Uf=664mV
2N3054            NPN      B=38  Uf=584mV
2N3772            RESISTOR   1.29O
2SD91               NPN      B=89  Uf=516mV

MPF102            N-JFET   I=2.1mA Vgs=1.50
IFR820              N-E-MOS     C=829pF   Vt=3.32V
IFR510            N-E-MOS   C=437pF  Vt=3.14V

1N6263            DIODE   Uf=585mV  C=0pF
1N4148            DIODE   Uf=710mV  C=0pF
1N4001            DIODE   Uf=664mV  C=13pF
NTE5812            DIODE   Uf=590mV  C=163pF
1N5404            DIODE   Uf=584mV  C=49pF
1N3002            DIODE   Uf=642mV  C=408pF
1N1183A            DIODE   Uf=512mV  C=0pf
MBR10H100CT  Dual Diode   2*DIODE   UF=368mV  370mV

LM336Z-2.5V         DIODE   Uf=2.03V  C=0pF
LM4041BZ1.2V         2*DIODE   Uf=1.23V  796mV

Green LED            DIODE   Uf=1.96V  C=4pF
Yellow LED            DIODE   Uf=1.85V  C=4pF
Red LED            DIODE   Uf=1.60V  C=18pF
Red LED            DIODE   Uf=2.35V  C=49pF

IS420 SCR            NPN      B=29 UF=497mV

1,000,000 .01% WW         Resistor   1002K
100,000 .01% WW         Resistor   99.45K
10,000 .01% WW         Resistor   10.08K
1,000 .01% WW         Resistor   1003
100 .05% WW         Resistor   99.8
752.768 .02%    WW         Resistor   753.7
again                     753.7
again                     753.7
again                     753.7
again                     753.7
1 .5% WW                  1.67
10 .5% WW                  10.4
Shorted                  .55
9,100,000 1% WW               9346K
27,000,000 1% WW               26.87M

10pF               Unknown
22pF               Unknown
32pF Mica 5%         Capacitor   32pF
47pF Mica 5%               48pF
100pF Mica 5%               105pF
120pF Mica                  118pF
150pF Mica 5%               151pF
180pf Mica 10%               189pF
301pF Mica                  310pF
360pF Mica 5%               364pF
470pF Mica                  467pF
560pF Mica 5%               556pf
3000pf Mica 2%               3024pF
8200pf Mica 1%               8128pF
11000pf Mica 5%               10.45nF
15000pF Mica 5%               14.39nF
17000pF Mica 2%               16.91nF
33000pF Mica 5%               33.35nF
2.0uF Mylar 12.5%               2128nF  ESR=.66o
4.0uF Mylar 2%               4054nF  ESR=.63o Vloss=.1%
234uf Alum Electro NP 10%            235.1uF  ESR=.61o  Vloss=1%
470uF Alum Electro               495.7uF  ESR=.39o  Vloss=1.2%
1000uf Alum Electro               922.2uF ESR=.65o Vloss=.5%
3300uf Alum Electro               3364uF ESR=.61o  Vloss=1.2%
8000uF Alum Elctro               8999uF  ESR=.56o  Vloss=1.3%
10,000uF Alum Electro            11.81mF  ESR.59o  Vloss=1.6%
1uF Tant                  1020nF  ESR9.6o  Vloss=.3%

10uH                     .7o  L=.01mH
100uH                     1.6o L=.10mH
2.5mH                     19.2o  L=2.52mH
44mH 3%                  54.8o  L=40.0mH
50mH audio                  44.8o  L=49.9mH
30mH telephone               3.3o  L=28.4mH
120mH military               166.3o L=121mH
250mH Telephone               32.5o  L=244mH
720mH                  43.9o  L=689mH
8.3H 61o                  61.5o  L=8.50H

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 10, 2013, 10:10:49 pm
IS420 SCR            NPN      B=29 UF=497mV

Optical coupled TRIACs aren't supported yet :-)

Quote
Shorted                  .55

That's a little bit strange because the self-adjustment measures the resistance of the probes and the tester takes that into account when measuring resistors. Are you using probe leads? Have you done the self-adjustment with the probe leads attached?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 22, 2013, 07:59:55 am
Firmware News

Karl-Heinz finished version 1.08k (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/)) with following highlights:
- support of DOG-M LCD modules with ST7036 controller
- measurement of leakage current for diodes and BJTs (used for hFE)
- 3 new UI languages
- several minor improvements

And I just released 1.10m (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/)):
- 2.5V voltage reference (hardware option)
- protection relay for discharging caps (hardware option)
- Zener voltage measurement >4V (DC-DC boost converter hardware option)
- 16MHz MCU clock
Title: Re: $20 LCR ESR Transistor checker project
Post by: true on October 22, 2013, 02:24:43 pm
Is there a page on differences between versions anywhere? Wiki? Something like that?

Should I make one? (not something I'd enjoy doing but it's info I would like to know anyway)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Flump on October 22, 2013, 06:36:19 pm
Can someone link to the best one of these to get please ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 23, 2013, 12:02:19 am
Is there a page on differences between versions anywhere? Wiki? Something like that?

There's no side-by-side comparison but most major differences are mentioned in the readme file of the m-version. A short ad hoc list for the m-version:
- no ESR (yet) and Vloss (caps)
- just two languages included
- no support for software UART (serial output)
- no support for alternative LCD module pins (stripboard version)
- just ATmega168 and 328
- UI with selectable hold mode (wait for key press) and menu
- PWM tool (select from several predefined frequencies and change the PWM ratio in 5% steps)
- several measurements differ in some details
- completely different logic for diode detection
- low resistance measurement (kind of :-)
- Zener tool (4-30/40V) is selected via menu
- IGBT detection (if 5V are sufficient)
- readable source code with tons of comments

Quote
Should I make one? (not something I'd enjoy doing but it's info I would like to know anyway)

We would keep you busy :-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 23, 2013, 12:14:11 am
Can someone link to the best one of these to get please ?

The best one is the one you build yourself :-) Actually you could choose any clone but make sure that it has got an ATmega328. The 168 doesn't got enough flash to support all features. And the clones without ISP pin header or pads could be less convenient to update.
Title: Re: $20 LCR ESR Transistor checker project
Post by: A Hellene on October 23, 2013, 03:27:23 am
Can someone link to the best one of these to get please ?
Here you are: This (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg299822/#msg299822) is what to look for and what to avoid, regarding a clone, and this (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg299866/#msg299866) is a deductive visual inspection round-up of five clones suggested by another fellow EEVBlogger; and this (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg263699/#msg263699) is what, for example, you can build.


-George
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 26, 2013, 08:39:22 pm
I picked up a few of these.
Hopefully I can also get those free solder splashes on the LCD thrown in (just kidding).

I have a few questions to you guys who have been through this already:
1. Was there a consensus on the ISP header such as the one Darrylp mounted?
2. Since this may have a ATmega168. Is it possible to retrofit an ATmega328P, ATmega328 or socket in the same package?
3. How can I tell them apart? Are they essentially the same beast or need further mods?
4. Wheres a good resource for info on AVR ISP programming?
5. Anyone got a good place to purchase headers, chips and programming related parts from?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 26, 2013, 11:47:22 pm
I have a few questions to you guys who have been through this already:
1. Was there a consensus on the ISP header such as the one Darrylp mounted?
2. Since this may have a ATmega168. Is it possible to retrofit an ATmega328P, ATmega328 or socket in the same package?
3. How can I tell them apart? Are they essentially the same beast or need further mods?
4. Wheres a good resource for info on AVR ISP programming?
5. Anyone got a good place to purchase headers, chips and programming related parts from?

1. Use what fits :-)
2. Yes, same package, same pinout.
3. If you're talking about the ATmegas, just compile and flash the firmware for the 328 and enjoy the additional featues. No hardware mods are required. You can distinguish the types by the chip's signature (using an ISP programmer) if the markings are sanded off.
4. Look at http://www.atmel.com/ (http://www.atmel.com/) for datasheets and application notes (AVR910).
5. Please set your country in your profile.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Frenchie on October 27, 2013, 02:28:45 am
I've laid out a SMD board with the intention of soldering it directly onto the back of an LCD with a pin header. I figure the board layout might be useful to someone else, so the Gerbers are attached and the board is shared at OSHPark (http://oshpark.com/shared_projects/ir4NKmKE (http://oshpark.com/shared_projects/ir4NKmKE)).

(http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=64843)

I'm currently waiting on the 0603 0.1% resistors to arrive with my next digikey order. I've tested with 5% resistors and everything works okay (of course not as accurately as it would otherwise be). Shown below is a breadboard test, in the final configuration I intend to back to back the board with the display (ie top side facing out) and solder them together with a pin header. Plugging both into a breadboard lets me get at the through hole components if I need to.

(http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/?action=dlattach;attach=64846)

Changes:

A quick word of caution, this is my RevC board, I renumbered my schematic to match Karl-Heinz Kübbeler's annotation and took the opportunity to make a  few very minor position & routing changes. Everything passes ERC/DRC so there should be no issues with this revised layout but I've not built it up to check. PM me if you instead want gerbers for the RevB which I know works. Murphy got me with RevA and I swapped one of the transistor's pins
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on October 27, 2013, 03:18:16 am
I saw another one of these on Ebay that had some sort of rudimentary function generator. And now I can't find it. 
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 27, 2013, 07:16:54 am
I saw another one of these on Ebay that had some sort of rudimentary function generator. And now I can't find it.

http://www.ebay.com/itm/161135107947 (http://www.ebay.com/itm/161135107947)

http://www.ebay.com/itm/321157000855 (http://www.ebay.com/itm/321157000855)

http://www.ebay.com/itm/150959457334 (http://www.ebay.com/itm/150959457334)


Nice work Frenchie on your PCB.  Did you make that yourself or?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on October 27, 2013, 10:27:06 am
I saw another one of these on Ebay that had some sort of rudimentary function generator. And now I can't find it.

http://www.ebay.com/itm/161135107947 (http://www.ebay.com/itm/161135107947)

http://www.ebay.com/itm/321157000855 (http://www.ebay.com/itm/321157000855)

http://www.ebay.com/itm/150959457334 (http://www.ebay.com/itm/150959457334)


Nice work Frenchie on your PCB.  Did you make that yourself or?

No, but I did see those as well. The one I saw showed them testing caps in the pictures, and also had a mp3-style oscilloscope connected to it in one of the pictures showing a wave form. But it did not have any BNCs. The LCD showed the frequency and voltage of the waveform it was outputting.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on October 29, 2013, 08:51:39 pm
Hey I finally found it again. Looks like it does have a BNC on the side in one of the pictures.

http://www.ebay.com/itm/Digital-Tester-Resistance-Capacitance-Frequency-Meter-Oscilloscope-Generator-50-/290998783979?pt=LH_DefaultDomain_0&hash=item43c0e10feb (http://www.ebay.com/itm/Digital-Tester-Resistance-Capacitance-Frequency-Meter-Oscilloscope-Generator-50-/290998783979?pt=LH_DefaultDomain_0&hash=item43c0e10feb)

Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 30, 2013, 07:47:54 am
I was thinking something along the lines of this.
I like the ZIF socket idea as you can just drop a component in or short test wires.
I would case mount it or put on a separate PCB to reduce opening and closing stresses. You can also change it later with no hassle.
9v battery compartment with door and external socket.

(http://i42.tinypic.com/2eulyqg.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 30, 2013, 09:11:53 am
I was thinking something along the lines of this.
I like the ZIF socket idea as you can just drop a component in or short test wires.
I would case mount it or put on a separate PCB to reduce opening and closing stresses. You can also change it later with no hassle.
9v battery compartment with door and external socket.

Another nice idea! Someone has built a version with all hardware options (2.5V reference, relay and boost converter) and put the ZIF socket and contact pads on a small doughter board.
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on October 30, 2013, 07:17:41 pm
Another nice idea! Someone has built a version with all hardware options (2.5V reference, relay and boost converter) and put the ZIF socket and contact pads on a small doughter board.

I think this someone is me, see https://github.com/maugsburger/avr-component-tester
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 30, 2013, 07:56:58 pm
I think this someone is me, see https://github.com/maugsburger/avr-component-tester

Got any photos of it complete?
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on October 30, 2013, 08:14:30 pm
Got any photos of it complete?

How many do you want? :D

http://www.mikrocontroller.net/attachment/191030/ttpl.jpg (http://www.mikrocontroller.net/attachment/191030/ttpl.jpg)
http://www.mikrocontroller.net/attachment/195731/Transistortester_AVR_C_defekt.jpg (http://www.mikrocontroller.net/attachment/195731/Transistortester_AVR_C_defekt.jpg)
http://www.mikrocontroller.net/attachment/193735/transtest.jpg (http://www.mikrocontroller.net/attachment/193735/transtest.jpg)
http://www.mikrocontroller.net/attachment/193128/ttester.jpg (http://www.mikrocontroller.net/attachment/193128/ttester.jpg)
http://www.mikrocontroller.net/attachment/192882/20131003_054944.jpg (http://www.mikrocontroller.net/attachment/192882/20131003_054944.jpg)
http://www.mikrocontroller.net/attachment/191023/tt2.jpg (http://www.mikrocontroller.net/attachment/191023/tt2.jpg)
http://www.mikrocontroller.net/attachment/189066/tt.jpg (http://www.mikrocontroller.net/attachment/189066/tt.jpg)
http://www.mikrocontroller.net/attachment/192834/IMG_20131002_161938.jpg (http://www.mikrocontroller.net/attachment/192834/IMG_20131002_161938.jpg)

Just seeing that I don't have the mentioned ZIF daugher board, but it should be possible to add one without problems, just expand the SMD daughter board to the left and add a ZIF socket there.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on October 30, 2013, 08:44:52 pm
I didn't know cat droppings came in 0.025uF ratings.  :-DD. I don't think that I've seen a brown capacitor before with a round end.

But I do like the board and also how you used a bare LCD.
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on October 30, 2013, 11:02:03 pm
Most of the pictures are taken by other users at mikrocontroller.net, I just did a batch order of these PCBs.

I didn't know cat droppings came in 0.025uF ratings.  :-DD. I don't think that I've seen a brown capacitor before with a round end.

It's from an old tube radio and quite dead (see vloss), therefore the capacity measurement failed and shows a much too high capacity.

But I do like the board and also how you used a bare LCD.

In fact this is not a bare LCD, but a dogm http://www.lcd-module.de/pdf/doma/dog-m.pdf (http://www.lcd-module.de/pdf/doma/dog-m.pdf)

Karl-Heinz finished version 1.08k (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/)) with following highlights:
- support of DOG-M LCD modules with ST7036 controller
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 31, 2013, 01:08:19 am
Just seeing that I don't have the mentioned ZIF daugher board, but it should be possible to add one without problems, just expand the SMD daughter board to the left and add a ZIF socket there.

IIRC the PCB I mentioned is from someone in the Ukraine, but yours is also nice! It even includes the PWM driver for the backlight ;-)

PS: A suggestion for a bench DIY version can be found at http://www.mikrocontroller.net/svnbrowser/transistortester/Hardware/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Hardware/Markus/).
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on November 04, 2013, 07:37:50 pm
Looks like someone was on to us for carefully scrutinizing chosen parts.

http://www.ebay.com/itm/NEW-Transistor-Tester-Diode-Triode-Capacitance-ESR-resistance-Meter-MOS-PNP-NPN-/221280589574?pt=LH_DefaultDomain_0&hash=item338559d706 (http://www.ebay.com/itm/NEW-Transistor-Tester-Diode-Triode-Capacitance-ESR-resistance-Meter-MOS-PNP-NPN-/221280589574?pt=LH_DefaultDomain_0&hash=item338559d706)

 :-BROKE
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 05, 2013, 01:08:05 am
Looks like someone was on to us for carefully scrutinizing chosen parts.

http://www.ebay.com/itm/NEW-Transistor-Tester-Diode-Triode-Capacitance-ESR-resistance-Meter-MOS-PNP-NPN-/221280589574?pt=LH_DefaultDomain_0&hash=item338559d706 (http://www.ebay.com/itm/NEW-Transistor-Tester-Diode-Triode-Capacitance-ESR-resistance-Meter-MOS-PNP-NPN-/221280589574?pt=LH_DefaultDomain_0&hash=item338559d706)

I like the design with the banana connectors (2mm?) and the ZIF adapter! But, as always, there's no documentation. Has anyone, who bought one of tester clones, ever received a manual or a link to the project webpage? 
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on November 08, 2013, 12:01:13 pm
The one I just brought for $25 is a blue back-lite version 2.4 board dated 2013/07/01 with ATmega168V 10AU
Draws 26mA at idle and 1.3uA settling down to 0.7uA when auto off.

I would not recommend it yet, requires further testing. 
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on November 10, 2013, 11:16:52 am
Just found my first bad cap with my ESR meter. A compact fluorescent lamp failed and I could hear a cap complaining.  After butchering the case got 3045nF with ESR of 4.8 Ohms on the 3uF 400v electrolytic (Aishi).  A 5% 1 Ohm load resistor was also reading 1.2 Ohms.
Title: Re: $20 LCR ESR Transistor checker project
Post by: cib3k on November 11, 2013, 08:59:56 am
Hi guys, what do you think about this:
http://www.ebay.co.uk/itm/DC12-Transistor-Tester-resistance-Meter-MOS-PNP-NPN-Diode-Triode-Capacitance-ESR-/290944824363 (http://www.ebay.co.uk/itm/DC12-Transistor-Tester-resistance-Meter-MOS-PNP-NPN-Diode-Triode-Capacitance-ESR-/290944824363?pt=LH_DefaultDomain_0&hash=item43bda9b42b)

It seems to already have an ATmega328, 0.1% resistors, 8MHz crystal and software version 1.07(k).
What's unusual is the built-in 9v battery and a DC power jack for 7.5-12v.
I'm not sure what this means: "Fuse, from low to high: F7DCF9".

The overview seems translated with Google Translate from this chinese page (http://item.taobao.com/item.htm?spm=a1z10.1.w4004-737437924.2.rNCbAy&id=17620914059). The pictures are standard pictures that also appear on other ebay auctions and seem obsolete compared to the stated capabilities of the tester. There's also a manual for a digital controller (REX-C100) that doesn't seem to have anything to do with the tester.

At the moment it would be difficult for me to just build a tester by myself - for various reasons. So I need to buy one, but I'm torn between this one and the one that Tony bought (http://www.ebay.co.uk/itm/Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-R-C-L-M328-/121183715380?pt=LH_DefaultDomain_0&hash=item1c371cc034). The latter also has ATmega328/8MHz crystal/software 1.07, but no 0.1% resistors and no built-in battery. I'm not sure if the 0.1% resistors make much difference, and I'm worried that the built-in battery/DC power jack might add some unnecessary circuitry that might increase electrical noise. What do you think?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 12, 2013, 12:50:42 am
Hi guys, what do you think about this:
http://www.ebay.co.uk/itm/DC12-Transistor-Tester-resistance-Meter-MOS-PNP-NPN-Diode-Triode-Capacitance-ESR-/290944824363 (http://www.ebay.co.uk/itm/DC12-Transistor-Tester-resistance-Meter-MOS-PNP-NPN-Diode-Triode-Capacitance-ESR-/290944824363?pt=LH_DefaultDomain_0&hash=item43bda9b42b)

I like the design with the banana connectors and the ZIF adapter.

Quote
It seems to already have an ATmega328, 0.1% resistors, 8MHz crystal and software version 1.07(k).
What's unusual is the built-in 9v battery and a DC power jack for 7.5-12v.
I'm not sure what this means: "Fuse, from low to high: F7DCF9".

The current k-version is 1.08k (1.09 is under development) and "F7DCF9" describes the fuse settings, which seem to be slighly off. The recommended fuse settings for a 328 with 8MHz crystal are hfuse 0xd9, efuse 0xfc and lfuse 0xf7. Someone mentioned that the boxed tester clone lacks an ISP header.

Quote
At the moment it would be difficult for me to just build a tester by myself - for various reasons. So I need to buy one, but I'm torn between this one and the one that Tony bought (http://www.ebay.co.uk/itm/Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-R-C-L-M328-/121183715380?pt=LH_DefaultDomain_0&hash=item1c371cc034). The latter also has ATmega328/8MHz crystal/software 1.07, but no 0.1% resistors and no built-in battery. I'm not sure if the 0.1% resistors make much difference, and I'm worried that the built-in battery/DC power jack might add some unnecessary circuitry that might increase electrical noise. What do you think?

I'd buy the boxed one. It's got a nice box with nice banana connectors (2mm?) and the 0.1% resistors. The bare one lacks an ISP header, maybe the boxed one too. 1% resistors work also fine if they are matched and you've built a custom firmware with the resistor values updated in config.h. Additional power circuitry isn't a problem, there's a version powered by coin cells via a boost converter.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on November 12, 2013, 01:26:09 pm
I have a 475K 630V polyester capacitor that's reading 47.28nF shouldn't it be 4700nF (4.7uF)?  Any ideas?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 12, 2013, 11:26:46 pm
I have a 475K 630V polyester capacitor that's reading 47.28nF shouldn't it be 4700nF (4.7uF)?  Any ideas?

Do you got similar problems with other caps too or just with that one?
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on November 13, 2013, 02:48:17 am
Those versions don't have ISP headers as the Processor is in a Socket DIP package and not SMD like other versions with the 128. Just take the chip out and reprogram it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on November 13, 2013, 09:55:54 am
Do you got similar problems with other caps too or just with that one?

Wondering why it would be out by almost exactly a factor of 100x.  Just this one so far I'll test some more, might be faulty and a coincidence.
Title: Re: $20 LCR ESR Transistor checker project
Post by: sync on November 13, 2013, 10:04:33 am
How big is it? A 4.7uF 630V film cap is huge. About 3-4cm.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on November 13, 2013, 02:21:41 pm
It's small 4x5x2mm it says 475K 630V on it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 13, 2013, 11:57:51 pm
It's small 4x5x2mm it says 475K 630V on it.

Or maybe ".475K" ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: sync on November 14, 2013, 01:02:00 am
It's small 4x5x2mm it says 475K 630V on it.
It's too small for a 4.7uF 630V film cap. The transistor tester is probably right with 47nF. I have no idea why it's marked 475K.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on November 14, 2013, 07:08:21 am
Maybe a 475k ohm resistor with close wrapped wires with a break in them causing a capacitance? :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: cib3k on December 02, 2013, 08:05:03 am
I bought the one from here (http://www.ebay.co.uk/itm/DC12-Transistor-Tester-resistance-Meter-MOS-PNP-NPN-Diode-Triode-Capacitance-ESR-/290944824363?pt=LH_DefaultDomain_0&hash=item43bda9b42b).

Here's how it looks inside:

  (http://img237.imagevenue.com/loc538/th_925389645_11_122_538lo.jpg) (http://img237.imagevenue.com/img.php?image=925389645_11_122_538lo.jpg) (http://img283.imagevenue.com/loc549/th_925391323_22_122_549lo.jpg) (http://img283.imagevenue.com/img.php?image=925391323_22_122_549lo.jpg)
     

I've labeled some of the components, in the pictures.

The values of the resistors, in KOhms, are the following:
R1: 0.680, R2: 470, R3: 0.680, R4: 470, R5: 0.680, R6: 470, R7: 10, R8: 32, R9: 3.3, R10: 27, R11: 100, R12: 10, R13: 3.3, R14: 0.56

R1-R6 are 0.1%, R7-R14 are 1%.

The ESR values of the Rubycon electrolitics (16V, 10uF) are 4.3 and 4.7 Ohms. They're high, but could be normal, according to some ESR charts. I couldn't find any official Rubycon documentation with ESR values.

The version of the board is 2.10 from 2013.06.20. Which seems rather odd, since 2.10 is an old version. I think I've seen a board labeled v2.10 with a 2012 date on it. There are also boards labeled v2.2, v2.4 and v3.0. So did they use an old hardware layout and slapped a 2013 date on it? I'll have to look more into it.

Anyway, it lacks an ISP header (not a problem) and the 2.5 volt reference. Anything else you notice?

I haven't properly tested yet, I'm a beginner and I don't have many components lying around.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JoeO on December 02, 2013, 08:22:17 am
Thanks for the nice write up and pictures.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 02, 2013, 11:56:40 pm
The ESR values of the Rubycon electrolitics (16V, 10uF) are 4.3 and 4.7 Ohms. They're high, but could be normal, according to some ESR charts. I couldn't find any official Rubycon documentation with ESR values.

Don't worry about them! Standard electrolytics are fine too.

Quote
Anyway, it lacks an ISP header (not a problem) and the 2.5 volt reference. Anything else you notice?

As long as you got an accurate voltage regulator the 2.5V reference doesn't give any benefits. It's more useful for a 7805 or 78L05. The PCB looks fine

Quote
I haven't properly tested yet, I'm a beginner and I don't have many components lying around.

Happy dumpster diving :-) E-junk is a good source for salvaging parts.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Kavaelect on December 12, 2013, 10:25:34 am
Hi guys. Bought one to these testers and only did a few component tests when it started to display the word  "Cell!" every time now.

Tried replacing battery, shorting all three test points to enter self test mode but nothing I do has made a difference.
Would love some help to resolve the issue.

Searched the internet for info but can't seem to find anything helpful yet.

BTW....have already bought a new one on ebay and still waiting for its arrival.

I am desperately keen to find a fault in my NAD M15 surround sound decoder.

Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 13, 2013, 02:15:07 am
Hi guys. Bought one to these testers and only did a few component tests when it started to display the word  "Cell!" every time now.

The tester tries to discharge what's connected to the probe pins before starting the tests. The default limit is about 3mV. Any higher voltage will cause the warning "Cell!". Have you checked some parts in circuit or a charged cap? If the tester worked fine before I'd assume that one of the MCU inputs for the probe pins might be toasted.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on December 17, 2013, 09:12:06 am
I made the Markus Frejek's AVR component tester, too.
Component tester with ATmega32 (http://www.youtube.com/watch?v=Qgc11si4obQ#)
http://www.mikrocontroller.net/articles/AVR-Transistortester (http://www.mikrocontroller.net/articles/AVR-Transistortester)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 18, 2013, 03:14:16 am
I made the Markus Frejek's AVR component tester, too.
http://www.mikrocontroller.net/articles/AVR-Transistortester (http://www.mikrocontroller.net/articles/AVR-Transistortester)

The original project is a tad outdated :-) You'll find the successor at http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester) offering much more features.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on December 18, 2013, 12:26:35 pm
Yes, but that did not work with my ATmega32.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Stonent on December 18, 2013, 10:18:40 pm
Quote
A connected capacitor can be measured in the range 35pF to 100MF with a resolution of up to 1 pF

Cool 100MegFarad. Will come in handy testing the decoupling caps at Comanche Peak. :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 19, 2013, 12:46:58 am
Quote
A connected capacitor can be measured in the range 35pF to 100MF with a resolution of up to 1 pF

Cool 100MegFarad. Will come in handy testing the decoupling caps at Comanche Peak. :)

:-) The upper limit is 100mF. The highest value I've tested so far is 22mF and the m-firmware goes down to 1pF if the input capacitance including probe leads exeeds 5pF (should be always the case) and the self-adjustment is done.
Title: Re: $20 LCR ESR Transistor checker project
Post by: roli_bark on December 29, 2013, 12:52:25 am
Will this "cheapo" ISP programmer be capable of programming the ATMega168P & ATMega328/P MCs ?

http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b (http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b)

It is listed as capable for the ATMega168 (non-P).
Title: Re: $20 LCR ESR Transistor checker project
Post by: jav on December 29, 2013, 02:09:39 am
Will this "cheapo" ISP programmer be capable of programming the ATMega168P & ATMega328/P MCs ?

http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b (http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b)

It is listed as capable for the ATMega168 (non-P).
Yes. Works fine. I have one of those and it's an USBasp  (http://www.fischl.de/usbasp/)clone. Mine came with an old firmware (2007), but as I ordered two, I used one to update the other.
Title: Re: $20 LCR ESR Transistor checker project
Post by: roli_bark on December 29, 2013, 03:31:30 am
Will this "cheapo" ISP programmer be capable of programming the ATMega168P & ATMega328/P MCs ?

http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b (http://www.ebay.com/itm/USB-ISP-Programmer-For-ATMEL-AVR-ATMega-ATTiny-51-Development-Board-New-/390641137707?pt=AU_B_I_Electrical_Test_Equipment&hash=item5af406b82b)

It is listed as capable for the ATMega168 (non-P).
Yes. Works fine. I have one of those and it's an USBasp  (http://www.fischl.de/usbasp/)clone. Mine came with an old firmware (2007), but as I ordered two, I used one to update the other.
Thanks.

Another question - On my SMD TransistorTester unit I'm trying to replace the ATMega168P (TQFP-32) to its drop-in replacement - the ATMega328P. Found (in Ali-Express) the ATMega328P-AU (10 Pcs for $15). Is the *-AU part OK ?

http://www.aliexpress.com/cp/compare-atmega328.html (http://www.aliexpress.com/cp/compare-atmega328.html)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 29, 2013, 07:26:35 am
Another question - On my SMD TransistorTester unit I'm trying to replace the ATMega168P (TQFP-32) to its drop-in replacement - the ATMega328P. Found (in Ali-Express) the ATMega328P-AU (10 Pcs for $15). Is the *-AU part OK ?

Should be fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: roli_bark on December 29, 2013, 08:52:49 am
10x !
Title: Re: $20 LCR ESR Transistor checker project
Post by: Benik3 on December 30, 2013, 11:31:40 am
There is a new firmware 1.10 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 08, 2014, 05:34:41 pm
ive purchased one of these on ebay and want to add m328 but have trouble finding latest hex. the mikro site is a hodge podge of confusing tex and hex files with line numbers and dont resemble any file type that avrdude recognizes. can someone tell me how to get a normal hex file there or link to another location? im mostly interested in inductance and milliohms, your help here would be greatly appreciated.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 09, 2014, 01:04:47 am
ive purchased one of these on ebay and want to add m328 but have trouble finding latest hex. the mikro site is a hodge podge of confusing tex and hex files with line numbers and dont resemble any file type that avrdude recognizes. can someone tell me how to get a normal hex file there or link to another location? im mostly interested in inductance and milliohms, your help here would be greatly appreciated.

Unfortunately the website doesn't support direct download of individual files. If your tester matches the standard design please go to  http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) and click "Download GNU tarball" for the tar.gz archive of the selected directory.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 09, 2014, 08:53:54 am
thank you. that is what i needed to know. it wasnt obvious to me what tarball meant.  i hope the cheap version i got on ebay ($9 bid) will allow me to do inductance and low ohms measurements i need. specially nice are the smd pads on that board.

my plan is, once its tested with 9v battery, will try to convert to 5v dc benchtop supply. hopefully just tying the battery check adc input high will disable any low voltage warning. thanks again for helping.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 10, 2014, 04:46:14 am
my plan is, once its tested with 9v battery, will try to convert to 5v dc benchtop supply. hopefully just tying the battery check adc input high will disable any low voltage warning. thanks again for helping.

You're welcome! If you're going for a direct 5V power supply I recommend to consider to add a 2.5V voltage reference. The low voltage warning/power-off can be disabled in the firmware (adjust values in config.h and recompile the source). Or a 7.5-12V supply would also be fine (based on the LDO regulator).
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 10, 2014, 06:25:35 am
i guess you want 2.5v ref because dc supply is noisy and not stable? specially usb cable from pc in my case. i do have lm336 if that seems to be a problem. high accuracy is not important to me but i would like to measure lower inductance and lower capacitance. i guess soldering a 27pf and subtracting would work for caps but what about lower inductance?

would 20mhz xtl instead of 8mhz improve ability to measure lower inductance?

can you describe the alorithm used for measuring inductance?

minimum hardware is two 680r and two 470k?

compiling is not convenient atm but i am set up for atmel asm and would like to experiment.

edit: nevermind... i found all info needed on inductance algorithm in section 5.4 of document "ttester_eng106k.pdf". thanks for an excellent design.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 11, 2014, 12:20:47 am
i guess you want 2.5v ref because dc supply is noisy and not stable? specially usb cable from pc in my case. i do have lm336 if that seems to be a problem. high accuracy is not important to me but i would like to measure lower inductance and lower capacitance. i guess soldering a 27pf and subtracting would work for caps but what about lower inductance?

The reason is the accuracy of the supply voltage. With a MCP1702 as LDO regulator you get 5V +/- 0.4%. Your PSU might deliver 4.7V or 5.3V and the voltage reference helps to determine the offset of the supply voltage. The tester will then compensate that for the measurements. A LM4040 would be a nice voltage reference. The LM366 is a hex sense amp ;-) The k-firmware supports capacitance measurements starting at about 30-35pF and the m-firmware at about 5pF. For measuring low inductance you'll need a proper LCR meter.

Quote
would 20mhz xtl instead of 8mhz improve ability to measure lower inductance?

The maximum clock rate currently supported by the firmware is 16MHz. The higher clock rate increases the timer resolution but that doesn't help much with low inductances (just a little bit). To measure lower inductances a higher test current would be needed. The inductance measurement is actually a nice by-product because the circuit wasn't designed for that. Other measurement methods are more suitable for supporting a larger range of values.

Quote
minimum hardware is two 680r and two 470k?

Three each. At the moment Karl-Heinz is testing also lower resistor values to gain higher test currents which improve some measurements.


Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 11, 2014, 01:00:32 am
Do anyone have any link to one of these that have the 328 microcontroller?, and possibly not one that is sanded down, but maybe all still are ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 11, 2014, 01:12:38 am
The LM366 is a hex sense amp ;-)

you misread. its lm336 which is 2.5v reference. ive been using them for years. not particualrly accurate but thats not important atm. i do have a couple 4040 but they are expensive and i got hundreds of lm336 in the junk box. in fact because accuracy is not needed at this stage i will probably not use any reference. im just thinking of throwing something quick together while waiting for the ebay one to arrive.

The maximum clock rate currently supported by the firmware is 16MHz.

right. my intent was to experiment with a basic asm version but now i see that inductance feature will never get down to the nanohenry range so will skip that idea. ill maybe build an oscillator type but even that may not be practical for the 433mhz and 2.4ghz indictors im dealing with. idk.

Three each.

if i only wire up 2 ea will it still perform as a two terminal tester? resistors, diodes, caps, coils? or does it check for all 6? right now im trying to throw together some minimum hardware till the one with full circuit and  0.1% resistors arrives.

i have one last question. does the hex file you gave me support serial? its mentioned in the diagram. i really want to build a usb/ftdi powered version like in the to-do list of that pdf. it would avoid the lcd and complicated power ckt. im hoping one of these can be built with 4-5 wires and couple components instead of dozens. ie minutes to build instead of hours/days. the fancy unit may not arrive for weeks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 11, 2014, 01:19:53 am
Do anyone have any link to one of these that have the 328 microcontroller?, and possibly not one that is sanded down, but maybe all still are ?

a quick search on ebay for "transistor tester" will come up with hundreds of links. many clearly show mega328. generally it looks like the $16-$20 ones are m328. the $8-$12 ones may be m8 or m328. seller says the one i got for $9 is m328 but ive learned not to believe a word. ive got large supply of m328 anyway so its not important in my case.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 11, 2014, 01:48:07 am
ok, I thought most of the used the 168, but it's just a chipswap if so happens, then it should be fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 11, 2014, 02:06:42 am
i think you are right, a lot of the middle priced ones seem to be m168. im not sure theres any practical difference at this stage of firmware except m8 definitely dont work with latest version. according to sellers the surface mount units all use the bigger chips but i would avoid them in case of bricking. the one i bought has no isp pads so thats another reason for socket. most ebay ads have photos showing the board so that helps.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 11, 2014, 02:30:38 am
Earlier in this thread I think someone published links to ones that was sure to be the newer one with the 328, but they are old links, so i was hoping that someone had some that was checked recently.
I see there are three of four types:
1) one with ZIF socket, and avr in dip: http://www.ebay.com/itm/271366797178 (http://www.ebay.com/itm/271366797178)

2) one that is boxed: http://www.ebay.com/itm/181109931348 (http://www.ebay.com/itm/181109931348)

3)  this one seems to have an 8L http://www.ebay.com/itm/271367115286 (http://www.ebay.com/itm/271367115286)

4) smd version, 168: http://www.ebay.com/itm/181161606431 (http://www.ebay.com/itm/181161606431)

And probably lots of other variations too..
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 11, 2014, 06:07:46 am
the 8$ one in your 3rd link is exactly what ive got coming. he swears its m328 but thats doubtful. he also said it was backlit but that is probably not true either. personally i dont care either way because i got tubes of m328 and backlit displays are cheap.

what i would really like to do is, while waiting, build a stripped down version with nothing more than four 5% resistors with power and txd going to a pc serial adapter. im wondering if that will work with the hex file posted above. it would also be nice if internal pull-ups were active so i dont have to wire external ones.

edit: i connected only 5v and pc4 and every time i reset get the following characters at 19200bps:

12V
 0V 1.32V

or

13v
5.02 VBF C

or

16v
F C

probably what it thinks is battery and some "ghost" component or self test warning. lots of garbage characters too. so thats a good sign. pretty good for NO external components at all. very encouraging so next im going to hook up some resistors and a cap across tp1-2 then see what comes out.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 11, 2014, 09:01:33 am
Based on description, it also seems like this is using same code?

but, support for big screen, that is something the chinese have added?

http://www.ebay.com/itm/181164691633 (http://www.ebay.com/itm/181164691633)

Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 12, 2014, 12:13:25 am
yes, i saw those. also the ones with signal generator built in. $50 is too much though imo.

so i wired the six resistors, tied pc4 & pc5 hi, and pullup on the button. it seems to be working after a fashion but not quite behaving as described in ttester_eng106k.pdf. on reset or button push with .1uf inserted i sometimes get a message "not calibrated" followed by confusing instructions to short terminals and/or plug in 100nf cap.  a couple times i got "100nf" reading but only one or two times at the beginning and not since. usually just a few cryptic letters.

this never happens when ports are shorted together as described in manual. sometimes i do get "0ohms 0ohms" which makes sense but, again, not reliable. no hint of self-test or calibration.

it might be wiring error or bad contacts or who knows what else. it does look like there are issues with the serial routines. lots of blank spaces and odd characters. im using a crystal and spacing is very consistent so unlikely a baud problem. maybe set for some oddball terminal protocol. it would be nice if it just printed a line or two with crlf in industry standard vt100/hyperterminal format.

i wont be able to play with code til vacation is over in couple weeks and it will be interesting to see how the ebay unit behaves when that arrives.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 12, 2014, 02:16:38 am
you misread. its lm336 which is 2.5v reference.

I see.

Quote
if i only wire up 2 ea will it still perform as a two terminal tester? resistors, diodes, caps, coils? or does it check for all 6? right now im trying to throw together some minimum hardware till the one with full circuit and  0.1% resistors arrives.

For self-adjustment all three are needed. And I think it might break some tests.

Quote
i have one last question. does the hex file you gave me support serial? its mentioned in the diagram. i really want to build a usb/ftdi powered version like in the to-do list of that pdf. it would avoid the lcd and complicated power ckt. im hoping one of these can be built with 4-5 wires and couple components instead of dozens. ie minutes to build instead of hours/days. the fancy unit may not arrive for weeks.

Please see the Makefile:
CFLAGS += -DWITH_UART

The software UART is enabled for that firmware image.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 12, 2014, 03:53:08 am
yes, since that post i wired the six resistors, tied pc4 & pc5 hi, and pullup on the button. it seems to be working after a fashion but not quite behaving as described in ttester_eng106k.pdf. in fact i bult two units like that. whats strange is different m328 work differently.

is it necessary to program the eeprom file?

i also see lots of signals that are not serial appearing on pc3. it is consistent though so dont look like noise. is this for standard vt100/hyperterminal type terminal? is there an example of serial output available anywhere?
Title: Re: $20 LCR ESR Transistor checker project
Post by: kubi48 on January 12, 2014, 10:33:10 am
You have always to program the flash memory with the .hex file and the EEprom with the .eep file for correct operation.
The serial output should be nearly the same as displayed on the LCD.
It is output with 9600 baud (1 Stop bit) with a 5V level.
The capacitor symbol is shown as -||- and the resistor symbol as -RR- .
The diode is shown as  ->|-  or  -|<-  .
The omega sign is replaced by Ohm and the µ sign is replaced by u .


 
Title: Re: $20 LCR ESR Transistor checker project
Post by: han on January 12, 2014, 11:16:23 am
i build with atmega 328, relay protection, USB supply,and internal voltage reference

i find the accuracy is depend on stability of the USB supply voltage (different USB power source different result)

i plan to use DC-DC converter from digikey.

whats the beter solution: ?

1. use 5V to 5V DC-DC converter
2. Use 5V to 9V DC-DC converter + 7805


 is there anyone that using dc-dc converter to supply the device?
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 12, 2014, 11:30:30 am
You have always to program the flash memory with the .hex file and the EEprom with the .eep file for correct operation.

thank you for that info. that may explain why same type chips operate differently. i will burn the ee file too next time. this is odd considering flashing new chips that have blank ee will not work.

im disappointed serial output is so complicated and dont work with standard terminal.

i will try to fix both problems when vacation is over and i can play with code and recompile.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Macbeth on January 12, 2014, 11:59:01 am
Quote
2) one that is boxed: http://www.ebay.com/itm/181109931348 (http://www.ebay.com/itm/181109931348)

I've got a couple of these. The display is backlit, and the AVR is a 168 (in a socket) and comes with 1.07k firmware. The ZIF is a nice touch!
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 13, 2014, 02:24:42 am
whats the beter solution: ?

1. use 5V to 5V DC-DC converter
2. Use 5V to 9V DC-DC converter + 7805

7805 or 78L05 aren't recommended. Please use a MCP1702 or something similar. Also add a proper ripple filter to the DC-DC converter.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 13, 2014, 02:32:26 am
thank you for that info. that may explain why same type chips operate differently. i will burn the ee file too next time. this is odd considering flashing new chips that have blank ee will not work.

Several strings, display characters, tables and adjustment data are stored in the EEPROM. No wonder you get strange display outputs ;-)

Quote
im disappointed serial output is so complicated and dont work with standard terminal.

There's an arduino version (http://www.pighixxx.com/lavori/ardutester/ (http://www.pighixxx.com/lavori/ardutester/)) supporting serial output and including a nice GUI tool.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 13, 2014, 05:02:13 am
i may try that ardunio version someday but im not a big fan of the environment. i prefer winavr by itself because its more compact, flexible, and powerful. uses 1/10th of pc resources too. admittedly ardunio is more popular with better support for beginners but not for me.

anyway thanks to that last hint from you and kubi eveythings working great now. obviously all the extra characters and signals were simply 0xff bytes from blank eeprom.  i have two of these working now at less than $2 in parts including avr. accuracy and stability are excellent.

this is an incredible project and already dozens of local fellow students and friends are as excited as me. thanks markus for a wonderful design and generous help.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 13, 2014, 10:50:14 pm
this is an incredible project and already dozens of local fellow students and friends are as excited as me. thanks markus for a wonderful design and generous help.

Markus Frejek designed the tester. Karl-Heinz (kubi) has carried on with the developement and I (another Markus ;-) have joined in with an alternative firmware. And we're happy to hear that you like the project.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 13, 2014, 11:28:57 pm
aha... i didnt know kubi was karl. what a team. thanks to both of you for bringing me up to speed on importance of ee in that build. im guessing putting those strings in ee is to save flash for the 8k version?

ive already sorted out half the "mystery" components in my junk box. i see what my final requirements are now and adjusting the makefile should do it. a stripped down version for mega8 with no powerdown seems to be the best fit for a group of local engineering students that im setting this up for. unfortunately i wont have access to my main computer for a couple weeks.

do you know if there is a hex file for mega8 anywhere on the net? also can you tell me what a "tex" file is? im not linux and a lot of this is new to me.

edit: i know what "tex' is now. nothing to do with hex or largest state in usa. i was using wrong search terms before.

i could still use a link to hex file for mega8. nothing useful on google so far. if you or anybody could help it would be appreciated.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 14, 2014, 12:14:16 am
this?
svn://mikrocontroller.net/transistortester/Software/trunk/mega8

Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 14, 2014, 01:01:58 am
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega8/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega8/)

thanks. sorry but im not good with these code suppositories. with your hint and a little link fixup im there.

this is just the build i need because others im involved with already have m8 breakout boards and only need the 6 resistors and a button. when im back to my big pc i will play with the makefile to enable pullups so i dont have to put one on the sw or tie bat and ref hi. also disable timeout because these are powered off serial/usb dongle. maybe investigate strings in flash instead of ee option too if theres room.

anyway none of these are important atm. i put the button on reset instead of pd7 which works great. heres a couple screen shots. within a fraction of a percent of precision meter readings. and as seen some of my "mystery" to-92 are pnp and others nfet.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 14, 2014, 06:32:44 am
I've ordered one of these (http://www.ebay.com/itm/New-Transistor-Tester-Capacitor-ESR-Inductance-Resistor-LCR-Meter-NPN-PNP-MOSFET-/251334183807?pt=LH_DefaultDomain_0&hash=item3a84af4b7f) which is a little expensive but I like the zif connector approach.

I think this is going to use the atmega 328 but I may want to change resistors to better tolerances and/or improve the voltage reference.

Anyone already done this?
Title: Re: $20 LCR ESR Transistor checker project
Post by: attila123 on January 14, 2014, 08:03:51 am
Hi guys!

What are the opinions about this ESR meter? I would need it to repairing LCD monitors, power supplies, etc, so in-circuit testing would be useful.

http://www.ebay.com/itm/Inductor-capacitor-Tester-Milliohm-Meter-ESR-Meter-LC-Meter-/130888138780?pt=LH_DefaultDomain_0&hash=item1e798a801c (http://www.ebay.com/itm/Inductor-capacitor-Tester-Milliohm-Meter-ESR-Meter-LC-Meter-/130888138780?pt=LH_DefaultDomain_0&hash=item1e798a801c)

Thank you!
Title: Re: $20 LCR ESR Transistor checker project
Post by: cellularmitosis on January 14, 2014, 09:59:14 am
Gandalf, I just got that exact unit in, and then found this thread.  I'd be happy to join in your efforts towards improving this little unit!
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 14, 2014, 11:10:33 pm
Atilla
These are all variations on a theme but I would beware of cheap Chinese copies.

Cellular
I'm mainly a hardware designer but can also do software - 60/40 is the split.  I like the utility of the meter just for having around my workshop evne if I do nothing to modify it.

I am interested in coming up with a revised set of hardware and letting someone else tweak the software - is that someone you I wonder?  Do you have any AVR studio skills?

Did you get schematics for yours or will we have to reverse engineer it - or more likely find out how close a clone it is of the original design?

I've read the whole thread and here's a summary (from memory) of things that can be improved:

1. The 2.5 volt reference voltage
2. Use 0.1% resistors where they matter
3. Put some thought into how best to lay out the component connection pads
4. Add an auto-discharge system (relay?) to discharge capacitors before testing

Stretch ideas:
a. Redesign the board to fit in a standard case
b. Add a frequency counter or does it already do this? - I have several iterations of a counter project that I did a while back using a PIC
c. Add a signal generator of some kind

Feel free anyone to chip in on this.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 15, 2014, 12:26:02 am
aha... i didnt know kubi was karl. what a team. thanks to both of you for bringing me up to speed on importance of ee in that build. im guessing putting those strings in ee is to save flash for the 8k version?

Exactly! Every byte counts ;-)

BTW, the 8k version has only a limited set of features and the 16k version has some limitations too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 15, 2014, 01:04:22 am
I've read the whole thread and here's a summary (from memory) of things that can be improved:

1. The 2.5 volt reference voltage
2. Use 0.1% resistors where they matter
3. Put some thought into how best to lay out the component connection pads

Stretch ideas:
a. Redesign the board to fit in a standard case
b. Add a frequency counter - I have several iterations of a project that I did a while back using a PIC
c. Add a signal generator of some kind

The voltage reference helps if you got a poor voltage regulator. With a MCP1702 there's no need for it. Just the probe resistors should be 0.1% types. There are lots of PCB layouts in the support forum. Haven't looked into the possibility of a simple frequency counter yet (if it might be feasable with the standard pin assignment). The m-firmware includes a PWM tool (frequency is selectable from a menu and the ratio is adjustable in steps of 5%). For more information please see Karl-Heinz' excellent documentation (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/)).
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 15, 2014, 01:24:09 am
Madires
Thanks for the advice.  your link takes me to a page that appear to have pdf documents available but I can't seem to download or view them, do I need some special software?

When I eventually get the files, is there a source code file that I can compile in AVR studio or do I need another tool? 

Is the source in C or assembly or mixed?

Thanks in advance.
Title: Re: $20 LCR ESR Transistor checker project
Post by: cowana on January 15, 2014, 01:30:19 am
To download those files, hit the "Download GNU tarball" link below the file names.

Andy
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 15, 2014, 01:48:38 am
When I eventually get the files, is there a source code file that I can compile in AVR studio or do I need another tool? 

The current version is always available at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) and should compile in AVR studio.

Quote
Is the source in C or assembly or mixed?

Mostly C, but a few pieces are in asm.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 15, 2014, 06:19:22 am
Thanks, got the files downloaded and into AVR Studio 6.  It seems to compile OK for the 328 version.

Don't have the kit from China, probably won't for 10 days or more.
Title: Re: $20 LCR ESR Transistor checker project
Post by: netdiver on January 15, 2014, 09:12:34 am
Dear All,
first of all I would like to thank Markus and Karl-Heinz for being here and supporting. This project is really great! Thanks also to Markus Frejek who started this incredible little swisstool.

I'm totally new to the world of microcontrollers and I'm here after googling a bit about the Transistor Tester I bought on the bay.
After reading some times this thread, I decided that I should upgrade my new tester. Here it is:
(http://eev.eevblog.com/forum/index.php?action=dlattach;topic=14399.0;attach=76707;image)
I removed the zener D1 and soldered an ISP header (10 pin) to program it.
Being a complete newbie, I downloaded WinAVR and followed the direction given in the english documentation, and tried right away to put the 1.10k version on it, as it has only a Atmega168. I compiled the Makefile in the "default" directory, as it was designed for the 168.
But programming gave an error. After a little investigation, I found out that maybe the latest version does not fit anymore on a atmega168, as it is a bit larger than internal flash.
I succeded in installing 1.09k (i tried only the k versions, as the m version is only suitable for an atmega 328).
Is it true that from 1.10k on, Atmega168 will be insufficient to hold the newest versions of the firmware?

Another question: which flags on the Makefile of the default directory are suitable for this chinese clone? For this first flash, I left everything untouched, but I can't understand completely the meaning of the flags and put them in relation to the hardware.

I will try to solder the 100nF bypass caps where Karl-Heinz did, but... hey I need something very small to solder over these small atmega pins!

Thanks in advance.
Best Regards from Lorenzo
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 15, 2014, 09:31:43 am
size is 17669 (0x4505) which is 1285 too much for m168. del a few features in the makefile and it will fit m168 or even m8.

i have a small problem myself. how do you run calibrate? whats really frustrating is it has been run twice before but im not sure how. shorting probes and hitting the button causes "not calibrated" message and instructions but then stops at  the site address. hitting the button during or after just starts that again.

the maunal and message says short probes and hit button and confirm within 2s but this dont work. what am i doing wrong?
Title: Re: $20 LCR ESR Transistor checker project
Post by: netdiver on January 15, 2014, 09:55:10 am
Thanks very much paulie for your quick reply!
I commented out in the makefile the CFLAGS += -DWITH_UART an that did the trick! Now the code is at 99.3% and fits into the atmega 168!

As for your problem, I don't have this behaviour. Shorting the three test points together and pressing the test button I can see on the display "Selftest mode ?" If I press the test button again, the selftest / calibration starts. At a point it says "Isolate probe!": pulling out the short from the test points the calibration goes on, then the software asks for a capacitor greater than 100 nF and the selftest ends shortly after.

Thanks again for solving my issue!
Best regards
Lorenzo a.k.a. netdiver
Title: Re: $20 LCR ESR Transistor checker project
Post by: netdiver on January 15, 2014, 10:25:48 am
A little step further... It's all in the documentation! So sorry for asking without having read thoroughly the docs.
I just noticed that to enable the extended test T1 to T7 it is necessary to disable one of the hFE measurement circuits.
I remove comment from NO_COMMON_COLLECTOR_HFE and now I have the T1 to T7 tests in the selftest mode, but I had to downgrade to 1.09k, as with 1.10k I'm not able to enable those extended tests without going over capacity of ATmega168.

Best regards.
netdiver
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 15, 2014, 10:46:36 am
hmmmm... strange thing is it worked at one time. i cant compile atm but use the 1.10 hex file below that markus sent me.

when i reset or hit button i get "testing 1-rr-2-rr-3 00ohm 00ohm" and that damn warning. its very accurate and stable in test mode but cant get it to calibrate again. the only thing different is tying the zener pin high but that shouldnt matter.

Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on January 15, 2014, 11:45:33 am
problem solved.... reflashing all 3 chip made no difference but new eeprom upload fixed it. idk why that would make a difference but calibration is working ok now. looks like something was corrupted in the eeprom. maybe time to look at that bod fuse setting. i was at least able to suppress the warning in all of them by copying the ee data from the original but the defect got copied too. sorry for wasting everybodies time, all working great again.

i gotta say its astonishing how accurate this is. even without calibration they had less than 1% deviation but after less than 0.1% compared against thousand dollar precision meter. amazing, and all with less than a dollars worth of hardware. thanks again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 16, 2014, 12:08:19 am
Netdiver
To put caps on the power pins, you can scrape at the copper ground fill to expose bare copper, prep it with flux, and then put solder on it (you'll need a strong iron to heat the ground plane).  Then you can put one end of the cap on the Atmega pin and the other to the newly-created ground pad.

Can anyone point me to the absolute latest schematic for this project?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 16, 2014, 12:58:04 am
Hi Lorenzo!

I removed the zener D1 and soldered an ISP header (10 pin) to program it.

That's the recommended procedure for the Chinese clones. Either remove the zener or replace it with a proper voltage reference.

Quote
I succeded in installing 1.09k (i tried only the k versions, as the m version is only suitable for an atmega 328).
Is it true that from 1.10k on, Atmega168 will be insufficient to hold the newest versions of the firmware?

The m-firmware supports the ATmega168 also. By setting the MCU to ATmega168 in the Makefile some features are disabled and the compiled firmware image will be small enough for 16kB flash and the smaller EEPROM. The k-firmware supports ATmegas down to 8kB flash with a limited set of features (read the documentation and edit the Makefile). If you like to have all available features you'll need an ATmega328.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 16, 2014, 01:05:13 am
Can anyone point me to the absolute latest schematic for this project?

The latest one is available at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) (click "Download GNU tarball" at the bottom).
Title: Re: $20 LCR ESR Transistor checker project
Post by: netdiver on January 17, 2014, 01:29:08 am
The m-firmware supports the ATmega168 also. By setting the MCU to ATmega168 in the Makefile some features are disabled and the compiled firmware image will be small enough for 16kB flash and the smaller EEPROM. The k-firmware supports ATmegas down to 8kB flash with a limited set of features (read the documentation and edit the Makefile). If you like to have all available features you'll need an ATmega328.

Thanks a lot Markus, so I can upload your firmware too!
Unfortunately my version has the SMD ATmega and my equipment lacks of SMD tools, so I'll stick with this version, until I find someone to sell it to!!

Thank you again for all your effort given in developing this project.

Lorenzo
Title: Re: $20 LCR ESR Transistor checker project
Post by: SteveM on January 21, 2014, 04:27:00 pm
Hi, I am new to this forum but I did read this entire thread and I have learned a lot about this little device.  I noticed on ebay that the Chinese have put this tester into a new package with the brand name YIWANJIA.  There are three buttons to the right of the center off/on/test buttons, but they are labeled in Chinese and there is no English manual for this tester.  Does anyone know what those three new buttons do?
Title: Re: $20 LCR ESR Transistor checker project
Post by: SteveM on January 21, 2014, 07:59:03 pm
Here are a couple of pictures to my post above to save the trouble of looking it up on ebay.  The specs seem to indicate it is the same circuit as the $20 LCR ESR transistor checker, but with updated software.


Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 21, 2014, 08:01:13 pm
according to other pictures, one button is power, and other is test, as seen here: http://www.ebay.com/itm/181164691633 (http://www.ebay.com/itm/181164691633)
Title: Re: $20 LCR ESR Transistor checker project
Post by: SteveM on January 21, 2014, 08:52:16 pm
That ebay seller messed up when attempting to label that picture.  The center button is actually two buttons.  The top half is on/test and the bottom half is off.  The three buttons to the right are something completely new.
Title: Re: $20 LCR ESR Transistor checker project
Post by: iloveelectronics on January 21, 2014, 09:51:07 pm
They must be re-using a case with completely different purpose...

The sockets and buttons are labelled as "send message", "volume/lookup", "menu/confirm", "dial", "shortcut" etc. And the device is labelled "Chinese SMS Sender" or something. Completely unrelated to ESR  :-//
Title: Re: $20 LCR ESR Transistor checker project
Post by: Rerouter on January 21, 2014, 09:55:40 pm
Time to put my foot in with this project

Just bought one of these, (hope i picked correctly)
http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 21, 2014, 09:56:27 pm
That ebay seller messed up when attempting to label that picture.  The center button is actually two buttons.  The top half is on/test and the bottom half is off.  The three buttons to the right are something completely new.

I thought those two buttons in the center would be for some paging in the display..
but the standard firmware is not supporting that type of screen ?, much bigger symbols, and also chinese text inside.
Title: Re: $20 LCR ESR Transistor checker project
Post by: SteveM on January 21, 2014, 10:12:56 pm
Thank you all for the replies and thank you iloveelectronics for the translation.  That is very puzzling.  I would think it wouldn't take much to manufacture their own plastic box and label it correctly.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 23, 2014, 12:41:23 am
Just bought one of these, (hope i picked correctly)
http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

It's one of the standard clones with an ATmega328. Might need an ISP header for firmware updates.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 23, 2014, 12:48:59 am
It's one of the standard clones with an ATmega328. Might need an ISP header for firmware updates.

Have you seen those with the bigger screen, is that something that is supported in the firmware now?, or is that an custom chinese hack?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 23, 2014, 12:58:02 am
I thought those two buttons in the center would be for some paging in the display..
but the standard firmware is not supporting that type of screen ?, much bigger symbols, and also chinese text inside.

It has to be a custom modification to support that LCD and include the extra symbols. Unfortunately the vendor doesn't seem to care about the project's Open Source Hardware nature.

BTW: A small Russian company will offer a transistortester clone with a nice enclosure (with pads for SMD, contacts for through-hole stuff and test clips) soon.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 23, 2014, 01:09:43 am
Thank you all for the replies and thank you iloveelectronics for the translation.  That is very puzzling.  I would think it wouldn't take much to manufacture their own plastic box and label it correctly.

Could be less expensive than manufacturing new boxes. We don't know how much the vendor pays for those boxes and LCDs. But I don't recommend to buy any of those testers because they obviously don't run the "official" firmware. So you would be stuck with the firmware version installed.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on January 23, 2014, 01:24:48 am
I thought those two buttons in the center would be for some paging in the display..
but the standard firmware is not supporting that type of screen ?, much bigger symbols, and also chinese text inside.

It has to be a custom modification to support that LCD and include the extra symbols. Unfortunately the vendor doesn't seem to care about the project's Open Source Hardware nature.

BTW: A small Russian company will offer a transistortester clone with a nice enclosure (with pads for SMD, contacts for through-hole stuff and test clips) soon.

Cool, will that one also include programming headers/port etc?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 23, 2014, 01:48:31 am
BTW: A small Russian company will offer a transistortester clone with a nice enclosure (with pads for SMD, contacts for through-hole stuff and test clips) soon.

Cool, will that one also include programming headers/port etc?

If I got that right it has a 10 pin ISP header (unpopulated).
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on January 28, 2014, 04:44:00 pm
How long before it is being sold? Where will it be sold and for how much? What will it be able to do and how well? I need an esr meter.
 Thanks for any reply.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 29, 2014, 08:17:05 am
How long before it is being sold? Where will it be sold and for how much? What will it be able to do and how well? I need an esr meter.

Got no idea about the date or price but they already offer ESR meters (http://www.radiodevices.ru/ (http://www.radiodevices.ru/)).
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on January 29, 2014, 04:05:28 pm
OK Thanks for responding.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gandalf_Sr on January 31, 2014, 11:09:44 pm
Mine has arrived.  Not done much with it yet but it works and appears reasonably accurate.

One aspect that's not as good as I thought is the ZIF socket.  It says 3M on it although it's probably a cheap Chinese copy; the issue is that it's about 5 mm from the top of the socket to where the actual connections start so testing a through-hole component that's been removed from a PCB would be almost impossible.  If I do a redesign, I'll go with the machined 0.1 pitch sockets + the SMT pads.
Title: Re: $20 LCR ESR Transistor checker project
Post by: J-D-H on February 19, 2014, 06:29:16 am
I bought one of these tester via eBay, but the LCD display does not seem to have back-lighting.  The tester's main PC board is labeled "Ver 2.4 2013/07/01"; the PC board holding the LCD display is labeled "Zijing Electronics".  Pads 15 and 16 on the display PC board are unused (no pins attached), but these two solder pads do have traces connected to them (hard to trace the connections -- no schematic, solder mask, etc.).  Does anyone know whether back-lighting on this tester's LCD module can be enabled?  If so, how?  Also, would the 25-50mA or so for the back-light LEDs be too much for the 5V regulator?  Any help would be appreciated!

John
Title: Re: $20 LCR ESR Transistor checker project
Post by: Rerouter on February 19, 2014, 06:49:17 am
JHD, look between the LCD and its board, if there is a gap it has no back-light installed, if it has something white and about 1mm thick in the way it is installed but not powered,

now if its a generic LCD there is generally a set of jumpers on the back and pads for a dropping resistor to power the back-light off the VCC rail
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 19, 2014, 07:07:26 am
I bought one of these tester via eBay, but the LCD display does not seem to have back-lighting.  The tester's main PC board is labeled "Ver 2.4 2013/07/01"; the PC board holding the LCD display is labeled "Zijing Electronics".  Pads 15 and 16 on the display PC board are unused (no pins attached), but these two solder pads do have traces connected to them (hard to trace the connections -- no schematic, solder mask, etc.).  Does anyone know whether back-lighting on this tester's LCD module can be enabled?  If so, how?  Also, would the 25-50mA or so for the back-light LEDs be too much for the 5V regulator?  Any help would be appreciated!

The first thing is to check if the LCD module has a backlight. Apply some mA to pads 15 and 16 and see if something happens. Use a PSU or a battery with a resistor to limit the current. The voltage regulator doesn't matter much. If it's able to provide enough current to power the backlight also you could simply add a resistor in series with the backlight. If not, build a small PWM backlight control with a current limiter, power the PWM by the 5V regulator and power the backlight by the battery directly (via a MOSFET with the current limiter). Or use some special LED driver (DC-DC converter, regulated by current).
Title: Re: $20 LCR ESR Transistor checker project
Post by: J-D-H on February 19, 2014, 08:42:11 am
JHD, look between the LCD and its board, if there is a gap it has no back-light installed, if it has something white and about 1mm thick in the way it is installed but not powered,

now if its a generic LCD there is generally a set of jumpers on the back and pads for a dropping resistor to power the back-light off the VCC rail

Thanks for the quick and clear info!  I hoped the display might be internally edge lit, but if the BL function is always done with discrete LED(s), I'm out of luck -- mine has none visible.  I'm thinking of trying to tack a lead to the 5v switched voltage someplace and then using this to power a couple of flat style LEDs wedged under the LCD (shaving the LED thickness as needed).  Having a BL when the circuit is working sounds like a nice idea.  However given the fairly small A-hr capacity of 9V batteries, it might be best to just forget the whole idea.....
Title: Re: $20 LCR ESR Transistor checker project
Post by: J-D-H on February 19, 2014, 09:06:48 am
The first thing is to check if the LCD module has a backlight. Apply some mA to pads 15 and 16 and see if something happens. Use a PSU or a battery with a resistor to limit the current. The voltage regulator doesn't matter much. If it's able to provide enough current to power the backlight also you could simply add a resistor in series with the backlight. If not, build a small PWM backlight control with a current limiter, power the PWM by the 5V regulator and power the backlight by the battery directly (via a MOSFET with the current limiter). Or use some special LED driver (DC-DC converter, regulated by current).

Thanks for your ideas!  If I understand correctly that back lighting of these LCD display modules is usually done via discrete LEDs, I see none behind mine.  I'll think about the idea of adding this function (as you suggested).  My first thought is to just use two LEDs in series via a simple dropping resistor to Vcc -- time for some experiments to see whether this sort of BL looks acceptable or not.....
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on February 19, 2014, 11:07:23 am
i can tell you none of the low cost ebay units have backlight. aside from cost issues the 9v battery life would be severely impacted. since i converted mine to 5vdc this was not an issue so swapping with a backlit unit was practical. trying to upgrade a non-lit one is not possible. theres more involved than just popping leds behind it. and why bother with lit units available for 2 bucks (shipped):

http://www.ebay.com/itm/LCD-Display-Character-Module-LCM-16x2-HD4478Controller-Blue-Blacklight-1602-TR-/181271994104?pt=LH_DefaultDomain_0&hash=item2a34a71ef8 (http://www.ebay.com/itm/LCD-Display-Character-Module-LCM-16x2-HD4478Controller-Blue-Blacklight-1602-TR-/181271994104?pt=LH_DefaultDomain_0&hash=item2a34a71ef8)

ill also mention asking the seller for details is another exercise in futility. mine swore it was backlit and used m328 not m8. both turned out not to be true. however for $10 i wasnt about to open a case. i will say the m8 version dont hold a candle up to the m328 hex file that markus posted here. no inductance, no calibration, etc and unbelievable spelling errors. since i built diy versions with serial io for less than a buck that work better i regret ordering that ebay one. live and learn.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Rerouter on February 19, 2014, 12:31:53 pm
a few pages back i posted a link to the one i purchased and it came with a back-light and the 328 mega in it, just missing an isp header,
Title: Re: $20 LCR ESR Transistor checker project
Post by: J-D-H on February 20, 2014, 03:20:44 am
i can tell you none of the low cost ebay units have backlight. aside from cost issues the 9v battery life would be severely impacted. since i converted mine to 5vdc this was not an issue so swapping with a backlit unit was practical. trying to upgrade a non-lit one is not possible. theres more involved than just popping leds behind it. and why bother with lit units available for 2 bucks (shipped):

http://www.ebay.com/itm/LCD-Display-Character-Module-LCM-16x2-HD4478Controller-Blue-Blacklight-1602-TR-/181271994104?pt=LH_DefaultDomain_0&hash=item2a34a71ef8 (http://www.ebay.com/itm/LCD-Display-Character-Module-LCM-16x2-HD4478Controller-Blue-Blacklight-1602-TR-/181271994104?pt=LH_DefaultDomain_0&hash=item2a34a71ef8)

ill also mention asking the seller for details is another exercise in futility. mine swore it was backlit and used m328 not m8. both turned out not to be true. however for $10 i wasnt about to open a case. i will say the m8 version dont hold a candle up to the m328 hex file that markus posted here. no inductance, no calibration, etc and unbelievable spelling errors. since i built diy versions with serial io for less than a buck that work better i regret ordering that ebay one. live and learn.

On adding back lighting, a simple test with a light source held near the edge of the LCD module seems to indicate that adding a couple of small LEDs might do the trick.  But a new LCD module complete with BL would be easier -- thanks for the link!  Maybe I'll get one of these, but first I'm going to think over the topic of battery drain.  That, and make some measurements to see whether my tester board's pins 15 and 16 are actually connected to anything.  BTW, I did think about contacting the seller and asking about the BL, but guessing the result, I didn't try <g>.
Title: Re: $20 LCR ESR Transistor checker project
Post by: J-D-H on February 20, 2014, 03:32:03 am
a few pages back i posted a link to the one i purchased and it came with a back-light and the 328 mega in it, just missing an isp header,

I'll look back and try to find the link.  Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on February 20, 2014, 06:02:42 am
a few pages back i posted a link to the one i purchased and it came with a back-light and the 328 mega in it, just missing an isp header,

yes, the more costly ones do come with m328 and backlight as mentioned in the listings for those. unfortunately low cost units like mine ($10 bo, $15 bin) cut corners in both categories.  what annoyed me was the seller did not tell the truth about that. pretty good deal though considering and only took me a couple minutes to upgrade mcu and display.

and its true you can put leds behind a non lit unit but there are factors like diffuser and different polarizing screen that degrade visibility so much its not worth it. i should also mention that the yellow/green backlight appears much brighter than the blue ones. at least to my eyes.
Title: Re: $20 LCR ESR Transistor checker project
Post by: linuxguru on February 22, 2014, 07:41:16 am

yes, the more costly ones do come with m328 and backlight as mentioned in the listings for those. unfortunately low cost units like mine ($10 bo, $15 bin) cut corners in both categories. ... i should also mention that the yellow/green backlight appears much brighter than the blue ones. at least to my eyes.

The units with the M328, yellow/green backlight, and ZIF socket can be found at $20..$25, Buy-It-Now. They also have more capable firmware, including DF/Vloss measurement of capacitors, Depletion-Mode JFET measurements, etc.

The stock units with yellow backlight run the backlight and the red LED at very high currents - I changed two resistors on the board to cut the current by a factor of 10 or 20, and it's still bright enough for normal daytime use. Battery life improves enormously after this mod.

Edit: IIRC, I changed R9 and R14 to 10k to reduce the current drawn by the backlight and the red LED. Pic of modified unit shown (with the LCD panel detached to show the board). The two capacitors have been left untouched - mine came with Rubycon YXA at both locations.



Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on February 22, 2014, 09:41:15 am
Just bought this:
Title: Re: $20 LCR ESR Transistor checker project
Post by: Macbeth on February 22, 2014, 11:03:10 am
Just bought this:
Could you have made a more smaller useless picture?

What is it? I would love to see, but... pixels...
Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on February 22, 2014, 11:21:33 am
Just bought this:
Could you have made a more smaller useless picture?

What is it? I would love to see, but... pixels...

Let me dig a bigger one from the store.  My toy has not arrived.  The pitches of  3 bottom connector are just nice for the bigger MOSFET.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on February 22, 2014, 12:23:49 pm
Looks like its this one http://www.ebay.com/itm/271367349891 (http://www.ebay.com/itm/271367349891)
Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on February 22, 2014, 12:53:38 pm
Looks like its this one http://www.ebay.com/itm/271367349891 (http://www.ebay.com/itm/271367349891)

Yes, same item.  I found some more interesting stuff from this store.
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on February 22, 2014, 04:25:19 pm
I was looking at that same one yesterday: Rechargeable Battery, test Zeners with up to 50V but why use the 168 and not the 328?
I don't think the shorting cap relay is implemented. It would be nice to see the PCB. What is the meaning of that 9V battery next to the unit?
Please post pictures once you get it.
Nice case :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 23, 2014, 12:18:40 am
The units with the M328, yellow/green backlight, and ZIF socket can be found at $20..$25, Buy-It-Now. They also have more capable firmware, including DF/Vloss measurement of capacitors, Depletion-Mode JFET measurements, etc.

Don't worry about the firmware! Get the latest and greatest at http://www.mikrocontroller.net/svnbrowser/transistortester/Software (http://www.mikrocontroller.net/svnbrowser/transistortester/Software) ;-)
I commend to buy only clones with ATmega328 since new features and most improvements require >16kB flash. If you got an older/cheaper one with an ATmega168 it makes sense to replace it with an ATmega328.
Title: Re: $20 LCR ESR Transistor checker project
Post by: obd.tech on February 23, 2014, 05:56:42 am
i'm new to this gadget and forum http://www.eevblog.com/forum/Smileys/default/smiley.gif, (http://www.eevblog.com/forum/Smileys/default/smiley.gif,) is the newest firmware 1.09? i looked at the link above and got a little confused :-)
whats the 'Programm fuer Optionen WITH_SELFTEST und AUTO_CAL ueberarbeitet' all about?
Thanks
p.s. how do you put a smiley in the post text?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 23, 2014, 07:02:24 am
i'm new to this gadget and forum is the newest firmware 1.09? i looked at the link above and got a little confused :-)
whats the 'Programm fuer Optionen WITH_SELFTEST und AUTO_CAL ueberarbeitet' all about?

The latest version (1.10k) is always in "trunk" and my alternative firmware (1.10m) in "markus". To download the directory click "Download GNU tarball".

Quote
p.s. how do you put a smiley in the post text?

This way: :) Just above the editor window you should see all emoticons. Click the one you like to add and it will be added at the cursor's position.
Title: Re: $20 LCR ESR Transistor checker project
Post by: obd.tech on February 23, 2014, 11:41:55 am
 Thanks for your help , i look forward to playing with my new toy and the things i hope to test & fix with the help and knowledge from this forum . Keep up the good work guy's http://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif (http://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)

mmm......smileys don't work for me.....i clicked but nothing.....i can only drag one down.....then it comes out wrong :-(
What am i doing wrong?
Title: Re: $20 LCR ESR Transistor checker project
Post by: sleemanj on February 23, 2014, 12:18:59 pm

It has to be a custom modification to support that LCD and include the extra symbols. Unfortunately the vendor doesn't seem to care about the project's Open Source Hardware nature.

FWIW, this appears to be the people who "developed" the large repurposed LCD version, fish8840 on Taobao.
http://item.taobao.com/item.htm?spm=a230r.1.14.35.QG5YBf&id=36323329572 (http://item.taobao.com/item.htm?spm=a230r.1.14.35.QG5YBf&id=36323329572)
Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on February 28, 2014, 08:14:14 pm
I was looking at that same one yesterday: Rechargeable Battery, test Zeners with up to 50V but why use the 168 and not the 328?
I don't think the shorting cap relay is implemented. It would be nice to see the PCB. What is the meaning of that 9V battery next to the unit?
Please post pictures once you get it.
Nice case :)

Fresh, not yet power up.  It is 328 uC.  But on the Taobao Chinese site, they said that it could range from 168 to 328.  As I mentioned on another post, those selling on ebay are normally trader and they could be carrying the old version.

Title: Re: $20 LCR ESR Transistor checker project
Post by: Jerby on March 03, 2014, 04:40:42 am
I build this tester and it works great. But it would be nice to have it on a PCB. Does anyone know if there are PCB's available, or batches to come?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Skimask on March 03, 2014, 04:45:39 am
It's ~$20 on eBay.
Is your time worth that little?
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on March 03, 2014, 05:08:24 am
I build this tester and it works great. But it would be nice to have it on a PCB. Does anyone know if there are PCB's available, or batches to come?

I created one (SMD), can be ordered eg via oshpark. https://github.com/maugsburger/avr-component-tester
Title: Re: $20 LCR ESR Transistor checker project
Post by: rr100 on March 05, 2014, 12:45:47 am
Got the one from post #277, seems to do what it says on the tin, backlight display&all, micro on DIP socket. "not on" current really low like 0.02 microamps (but that's my last digit on my multimeter so don't trust it much except as ... really low). I don't think backlight will be much of a problem to the battery as it shuts down itself rather quickly (but still not annoyingly quick).
Title: Re: $20 LCR ESR Transistor checker project
Post by: guido on March 05, 2014, 09:22:38 am
have the same one and made the following changes:

  - two SMD 47nF caps added to AVCC, DVCC to gnd (on the pins). Original cap removed
  - MC1403 2.5V reference added to pin27 (happened to have that one in the parts bin)
  - ic socket replaced with a good one
  - latest sw version

to do
 - change measurement resistors to 0.1% types (680/470k).
Title: Re: $20 LCR ESR Transistor checker project
Post by: rr100 on March 11, 2014, 10:26:57 pm
Did not manage to break the ZIF socket yet (I don't think is particularly bad, probably it might break if you put something thicker and you try to close it but works.

On what I can double check it seems to get 2 significant digits (note: that's not the same as 1%!), all in all quite satisfied.
I think it wouldn't be hard to include some marginal input protection and the requiered analog stage to make it measure something like 0-100V at least and maybe one shunt just to have everything completed as a small multimeter (it can be made much compact if needed, mine is all through hole).

I would really use such a toy, sometimes you just need a multimeter but is not critical enough and is not ofthen enough and I can't justify the weight of a full unit (even a small one). I got to a point where I was checking batteries with a bus pirate (which I had with me because I needed now and then for the serial capabilities). This has everything it needs, including a display!
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 12, 2014, 01:21:48 am
On what I can double check it seems to get 2 significant digits (note: that's not the same as 1%!), all in all quite satisfied.
I think it wouldn't be hard to include some marginal input protection and the requiered analog stage to make it measure something like 0-100V at least and maybe one shunt just to have everything completed as a small multimeter (it can be made much compact if needed, mine is all through hole).

That's something we should consider for a future Tester+. The nice thing about the current design is that it is very simple and easy to build. The other important point is the firmware compatibility. The k-version supports several modifications meanwhile and it's quite hard to check all variations for each code change. Supporting several different hardware versions makes the firmware development much more complicated.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 12, 2014, 01:38:02 am
The new m-version 1.11m is released (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/)). What's new?
- several minor improvements
- BJTs with base emitter resistor
- BJTs with freewheeling diode on the same substrate
- detection of (un)symmetrical drain and source for depletion mode FETs
- detection of body diode for depletion mode FETs
- improved pinout detection for Triacs (G, MT1 & MT2)
Title: Re: $20 LCR ESR Transistor checker project
Post by: SeanB on March 12, 2014, 02:05:26 am
Got mine this week, and it is good enough to use for checking semiconductors, mid range capacitors and resistors. Going to keep it in my tool box for general quick testing.
Title: Re: $20 LCR ESR Transistor checker project
Post by: rr100 on March 12, 2014, 02:41:18 am
Just bought one of these, (hope i picked correctly)
http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com.au/itm/200960094152?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

It's one of the standard clones with an ATmega328. Might need an ISP header for firmware updates.

Will probably upgrade the firmware every now and then, any advantage in adding the ISP header versus taking the micro out (is on a socket)?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 12, 2014, 02:54:10 am
Will probably upgrade the firmware every now and then, any advantage in adding the ISP header versus taking the micro out (is on a socket)?

Less mechanical stress. Choose whatever suits you better.
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on March 17, 2014, 03:45:39 am
Does anyone know where an English version of the 'changelog.txt' file located here?
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/)

Just picked up a newer version of the tester off ebay and am looking for firmware options.  I've attached a copy of the file for easier access.


Update:
I put the file through Google Translate and came up with this (I've cleaned it up a little).  Can you take a peek and give feedback?  Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 28, 2014, 05:11:45 am
Does anyone know where an English version of the 'changelog.txt' file located here?

AFAIK Karl-Heinz doesn't provide an English version yet. The CHANGES file for the m-firmware is in English anyway ;-)

Quote
I put the file through Google Translate and came up with this (I've cleaned it up a little).  Can you take a peek and give feedback?  Thanks!

I think I'll suggest to Karl-Heinz to maintain an English version too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 28, 2014, 05:19:53 am
Some news about current firmware changes. The trunk version of the k-firmware supports:
- in-circuit capacitance and ESR measurements
- frequency measurement (hardware option)
- squarewave signal generator
- PWM generator

The new m-firmware currently under development will include ESR and in-circuit ESR measurements.
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on March 28, 2014, 06:10:31 am
Thanks for the info and update (as always)!

Did you have a chance to look over the translation?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 28, 2014, 08:58:31 am
Did you have a chance to look over the translation?

Yep. Please don't be disappointed, it still needs some work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on March 28, 2014, 09:26:42 am
Yep. Please don't be disappointed, it still needs some work.

On, not at all!  The only disappointment I have is in the lack of feedback.  Please feel free to offer suggestions/translations.  I'm looking forward to it!
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 28, 2014, 08:57:07 pm
On, not at all!  The only disappointment I have is in the lack of feedback.  Please feel free to offer suggestions/translations.  I'm looking forward to it!

I'll send you a private mail.
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on March 29, 2014, 03:19:27 am
Got it, thanks!  I'll re-up a new version of the file once I have a chance to chew-over all your edits.  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 01, 2014, 02:11:46 am
Some news about current firmware changes. The trunk version of the k-firmware supports:
- in-circuit capacitance and ESR measurements
- frequency measurement (hardware option)
- squarewave signal generator
- PWM generator

The new m-firmware currently under development will include ESR and in-circuit ESR measurements.

is there a hex file version available? english description of the freq counter anywhere?

nothing obvious at mikrocontroller.net site. i dont speak german and like many diy hobbyists not good with code suppositories.  i know links have been posted before but this thread is really big now and nothing in post #1 so if anyone has any handy it would save a half hour of searching. thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 01, 2014, 09:50:12 am
Source and some HEX files for common setups are available at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) (click "Download GNU tarball"). Docs are at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) (just ttester.pdf , but unfortunately you have to download the whole directory).
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 01, 2014, 11:00:47 am
thank you, i dont know why i have such trouble getting back to that link. its in my favorites but i have so many.... anyway i got "mega328" which i assume is most common. and this time i know what tarball is and that ee image is required. one question... i dont read german so what does "2uf-50mf" mean?

lol. just kidding! thanks again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: quantumvolt on April 06, 2014, 03:37:55 pm
I have seen this project for a long time, but until recently it never occured to me to look closer at it. But a few weeks ago I bought one of the eBay-clones. It turns out to be an almost unbelievable good instrument considering its simplicity and low cost.

I have - for a long time - been buying many different lots of the Russian 0.5% capacitors from eBay. As an example:

One of the lots I bought is (now) 18 pieces 0.0333 uF +- 0.5% - that is 33.3 nF nominal value. First I sorted them with a 6.5 digit DMM measuring the AC voltage across them when in series with a precision low tempco resistor and exposed to a sinus signal. Then I grouped them (by the last digit xx.xY nF) by using a DMM with capacitance meter. They all fell in bins from 33.26 to 33.45. This is spread of a bit less than 0.6%. I picked out the median bin (the spread of values was like a very flat bell curve - so I guessed that the mean and median value would be quite equal).

I then tested the 3 capacitors with median value in the tester. They all read 33.38 nF (which is appr. +0.24% relative nominal value 33.30 nF). This is probably too high value for the 3 center units in a lot of 18 units with +-0.5% tolerance.

Then I tested parallel and series combinations (all measurements repeated several times) and got very surprised:

All 3 units measure 33.38 nF

3 combinations of 2 units in parallel: 66.76-77
1 combination of 3 units in parallel: 100.2

3 combinations of 2 units in series: 16.69
1 combination of 3 units in series: 11.12-13

3 combinations of 1unit in parallel with [2 units in series]: 50.07
3 combinations of 1 unit in series with [2 units in parallel]: 22.25

All measurements agrees to within one count on the last digit with the formulas for capacitor combinations (around 0.1% or better linearity). There is no detectable offset in this tester/meter since this would have been disclosed for pure parallel (and series) combinations. There probably is a small gain error around +0.25% (appr. 33.38 divided by 33.30) - assuming that the median bin in close to nominal value 0.0333 uF. I have no way to check this unless I send the capacitors to someone with a meter that is 0.1% or better.

I thought I should fix up the meter (reference / pull up for "Vcc= ...", regulator, precision resistors, decoupling, tin the 3 measurement port traces etc.), but I won't touch it until I get the second one I have ordered now. That way I will know if I have been lucky or if I am tricking myself (no way ...)

Anyway - I have checked some 50 capacitors and inductors with tolerance 1% or less, and just in a few cases has the reading been out of spec'ed error.

An amazingly good little gadget.



Title: Re: $20 LCR ESR Transistor checker project
Post by: obd.tech on April 07, 2014, 10:50:39 am
Hi, newbies help please   ::)
How do i find out what firmware my new tool has (bought the one in the plastic case with the 328 chip) Is there a trick to finding a menu on the display for any different options? A simple new user guide would be good  :)
What are the recommended 'mods' apart from the resistor change to dim the lighting/power save?
keep up the good work  :clap: on this handy gadget (i just need to learn, how to use it now  :-\ )
Thanks to all  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 08, 2014, 12:00:53 am
How do i find out what firmware my new tool has (bought the one in the plastic case with the 328 chip) Is there a trick to finding a menu on the display for any different options? A simple new user guide would be good  :)
What are the recommended 'mods' apart from the resistor change to dim the lighting/power save?

Based on the firmware version the version is displayed when powering up, down, or in the selftest mode. The older k-versions don't have a menu at all, but the latest k-version offers a menu for some extras (long key press). Please download the documentation of the last release at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/) (click "Download GNU tarball"). You'll find all mods in the documentation.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on April 08, 2014, 12:10:18 am
I downloaded that file now, and it's version 1.08k?, a file I downloaded somewhere in januar is version 1.10k?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 08, 2014, 12:37:53 am
I downloaded that file now, and it's version 1.08k?, a file I downloaded somewhere in januar is version 1.10k?

1.10k is the version currently under development (source at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) und doc at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/)).

BTW: 1.12m (m-firmware) was released a few days ago. New features are ESR and ESR-in-circuit.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on April 08, 2014, 11:21:07 am
Sorry But I am lost! Which one have all of you found is the best backlit one, and what do you have to do to make it  better? Is it set up to download the new file or do you just find the points and do it? Any videos of the process on this item.
Thanks for any help.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 08, 2014, 10:32:19 pm
Sorry But I am lost! Which one have all of you found is the best backlit one, and what do you have to do to make it  better? Is it set up to download the new file or do you just find the points and do it? Any videos of the process on this item.

Of course it's the one I've built myself :-) It has got a PWM and a current limiter for the backlight (see the SVN for the schematic). Karl-Heinz' documentation has a section about the ebay clones, known hardware issues and how to fix them. Other possibilities for improvements are the hardware options like protection relay or high voltage Zener. The current method for updating firmware is ISP. So you will need an ISP programer (required anyway if you're playing with Atmel MCUs  ;-). BTW, you can use an Arduino as programer too. There aren't any how-to videos specificly for the TransistorTester, but if you search for "atmega ISP" you'll find tons of tutorials.
Title: Re: $20 LCR ESR Transistor checker project
Post by: fluxcapacitor on April 08, 2014, 11:05:46 pm
I downloaded that file now, and it's version 1.08k?, a file I downloaded somewhere in januar is version 1.10k?

1.10k is the version currently under development (source at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) und doc at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/)).

BTW: 1.12m (m-firmware) was released a few days ago. New features are ESR and ESR-in-circuit.

Great work madires, and karl-heinz. I`m interested in the in-circuit testing ,can anyone recommend which one to buy.Will any with the 328 do .
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 08, 2014, 11:24:57 pm
Great work madires, and karl-heinz. I`m interested in the in-circuit testing ,can anyone recommend which one to buy.Will any with the 328 do .

Thanks! Yes, any clone with an ATmega328 and a text based LCD will work fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on April 09, 2014, 11:21:40 am
Thanks Madires for responding. I will look at ebay and see if I can figure out which one to buy.
Thanks again.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 09, 2014, 06:15:13 pm
My first post and hello to all. I have all the parts needed to make this ttester and i have a couple of questions:
1. is this the correct fuses for atmega328-pu with external 8 mhz crystal ( hfuse 0xd9, efuse 0xfc, lfuse 0xf7) (lockbit- 0xfc)
2. there is an svn link for m328, can i use that?
3. im going to use avrdudess gui for avrdude, are there any issues with it, like it wont work or something.?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 09, 2014, 07:24:32 pm
My first post and hello to all. I have all the parts needed to make this ttester and i have a couple of questions:
1. is this the correct fuses for atmega328-pu with external 8 mhz crystal ( hfuse 0xd9, efuse 0xfc, lfuse 0xf7) (lockbit- 0xfc)
Yes!

Quote
2. there is an svn link for m328, can i use that?
That's http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) (click "Download GNU tarball"). The hex file is for the flash and the eep file for the EEPROM. If you add any hardware option please download the source code (trunk = current version under development), edit the Makefile and compile the firmware yourself.

Quote
3. im going to use avrdudess gui for avrdude, are there any issues with it, like it wont work or something.?
Haven't tried avrdudess myself but I assume that it will do the job.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 09, 2014, 07:35:03 pm
hey thanks madires for replying. im gonna try it out now. thanks again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 11, 2014, 09:39:11 pm
first thing first ok, im a newbie so please bear with me.

1. ive got an atmega328-pu with arduino bootloader.
2. im using avrdude with avrdudess as gui.

when i connected the chip with 8mhz crystal, avrdude cant' talk to the chip. but when i swapped it out with a 16mhz its recognized. i know that the bootloader is set with 16mhz, but how can i program it with 8 mhz as the code requires an 8 mhz crystal? any guidance is appreciated.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 11, 2014, 10:35:57 pm
1. ive got an atmega328-pu with arduino bootloader.
2. im using avrdude with avrdudess as gui.

when i connected the chip with 8mhz crystal, avrdude cant' talk to the chip. but when i swapped it out with a 16mhz its recognized. i know that the bootloader is set with 16mhz, but how can i program it with 8 mhz as the code requires an 8 mhz crystal? any guidance is appreciated.

Have you connected the ATmega to your PC via a serial interface directly or are you using an ISP programmer?
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 11, 2014, 10:48:39 pm
thanks for responding madires.

 im using usbasp as an isp programmer.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 11, 2014, 10:59:19 pm
thanks for responding madires.

 im using usbasp as an isp programmer.

Actually the crystal frequency and the bootloader shouldn't matter because the programmer will set the ATmega to ISP-mode. Have you connected a pull-up resistor to the reset pin? Please post the fuse bits if you're able to read them.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 11, 2014, 11:19:02 pm
yes a 10k resistor is connected at pin 1 of the atmega328.
here's a screenshot of the gui:

(http://i59.tinypic.com/26284tf.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 12, 2014, 12:06:10 am
yes a 10k resistor is connected at pin 1 of the atmega328.
here's a screenshot of the gui:

I can't see any obvious  issue. You could try changing the bit clock for the 8MHz crystal.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 12, 2014, 08:09:11 am
how do i go about changing the clock bit?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 12, 2014, 10:21:56 pm
how do i go about changing the clock bit?

The bit clock is the speed the programmer talks to the ATmega. Please see avrdudess in the progammer section, port, baud rate and then bit clock (-B). BTW, -B is the commandline option used for avrdude. You could try to lower the speed. The recommendation is that the ISP clock should not exceed 1/4 of the CPU clock.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 13, 2014, 09:32:53 pm
Hey thanks madires for the guidance. I've managed to build the tester and its awesome.  Its 1.10 version. The different function is cool, again thanks a lot.
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on April 14, 2014, 03:04:09 am
I see that 1.10k has been moved (added) to the 'Tags' folder:
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/?sortby=date (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/?sortby=date)

I'm assuming that this means 1.10k is 'done' and he's now working on 1.11k?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 14, 2014, 06:02:08 am
I'm assuming that this means 1.10k is 'done' and he's now working on 1.11k?

That's right!
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on April 14, 2014, 06:25:53 am
This is EXCITING!!!  ... or is it!?   Sooo mysterious!  :D
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on April 18, 2014, 03:35:21 am
On ebay it seems that there are three other variations that have been developed of this:
http://www.ebay.com/itm/171285924831 (http://www.ebay.com/itm/171285924831)

http://www.ebay.com/itm/181164691633 (http://www.ebay.com/itm/181164691633)

http://www.ebay.com/itm/201074091766 (http://www.ebay.com/itm/201074091766)

According to the description, it seems like it have to be the same, and same firmware, but with some modifications, too bad, as it doesnt seem like there are any upgrade options, or no firmware source available, because the hardware starts to look very interresting.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on April 18, 2014, 03:49:33 am
They look nice, but in fact they do not tell you more.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on April 18, 2014, 03:54:17 am
I prefer this old design with HD44780 compatible LCD, because they are cheap, easy to buy, and they will be probably always available.
Title: Re: $20 LCR ESR Transistor checker project
Post by: g***! on April 18, 2014, 05:13:39 am
I have the version, in the second picture in post 361....It arrived today. Its all SMD with an M328P and an unpopulated space for a 10 pin programming header.
Along the top edge of the board is another unpopulated space for a 16 pin header....interesting!
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 18, 2014, 05:40:46 am
I have the version, in the second picture in post 361....It arrived today. Its all SMD with an M328P and an unpopulated space for a 10 pin programming header.
Along the top edge of the board is another unpopulated space for a 16 pin header....interesting!

The 16 pin header might be for a HD44780 display. I don't recommend to buy the Transistor Testers with the graphics display because they require a modified firmware, i.e. you can't use the latest release from the official repo. You'll be reliant on someone in China updating the firmware and I doubt that the source is available publicly.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on April 18, 2014, 06:08:39 am
The 16 pin header might be for a HD44780 display. I don't recommend to buy the Transistor Testers with the graphics display because they require a modified firmware, i.e. you can't use the latest release from the official repo. You'll be reliant on someone in China updating the firmware and I doubt that the source is available publicly.

Good point
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on April 18, 2014, 06:27:34 am
Quote
Good point

The code is fairly well packaged (all in lcd-routines.c/.h). So if you ever need to port it to a different display, you just need to implement your own lcd-routines.c/.h and recompile.

I did it with a nokia 7110 display - which looks to be similar to the graphics lcds shown earlier.
Title: Re: $20 LCR ESR Transistor checker project
Post by: at2marty on April 18, 2014, 06:58:53 am
I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 18, 2014, 11:29:51 am
i've changed my firmware to version 1.7k coz i have no use of the other function just yet. but good to know that its there if ever you need them. BTW, anyone have a link to the writeup of these tester, all versions i mean? I only found two of these which are versions 96k and 107k.
Title: Re: $20 LCR ESR Transistor checker project
Post by: free_electron on April 18, 2014, 03:30:19 pm
I was looking at these today. Found em on ebay and discovered they were based of the microcontroller.net project and also documented on eevblog.

I want to make a nice board for these, includong the booster for the zeners, the shorting relays to protect the inputs and the other options not commonly found in the wingpangpong versions.

The board must fit a nice handheld box with proper battery holders. I will use either 4 aa cells or go with a rechargeable lithium battery (usb) in which case i awant to add a usb uart.

Now, i do like the graphical display... Anyone has the code for that ? If not i will use the dogm series displays.

I am going to make a connector plate so ican push sot23, sot89 sot 232 and many other smd packages on it to find out what they are.

I will release artwork as public domain and have a bunch of em made by itead so they are cheap.

Anyone interested in the bare boards. For the cost of an envelope and international stamp....
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 18, 2014, 03:50:44 pm
I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 18, 2014, 03:58:16 pm
i've changed my firmware to version 1.7k coz i have no use of the other function just yet. but good to know that its there if ever you need them. BTW, anyone have a link to the writeup of these tester, all versions i mean? I only found two of these which are versions 96k and 107k.

You'll find the docs for the old firmware versions at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/old/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/old/english/) and the old firmwares at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/tags/). The current version under development is in the trunk directory and the m-firmware at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/). To download directories please click "Download GNU tarball" at the bottom.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 18, 2014, 04:03:29 pm
I will release artwork as public domain and have a bunch of em made by itead so they are cheap.

If you like we could put it into the official repo (there's a hardware section already).
Title: Re: $20 LCR ESR Transistor checker project
Post by: SeanB on April 18, 2014, 06:41:15 pm
I will nibble for a few boards, then build them up for the local HAM club. that should keep them busy ( and me as well) for a week or three building them. Will pull out the odd displays I have to use there as well.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on April 18, 2014, 07:50:05 pm
an interesting twist would be to make an arduino-shield that has all the hardware other than the mcu.
Title: Re: $20 LCR ESR Transistor checker project
Post by: at2marty on April 18, 2014, 08:15:28 pm
I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.

That's good to hear.  I would be more-than-willing to contribute in any way that I can.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on April 18, 2014, 08:17:01 pm
an interesting twist would be to make an arduino-shield that has all the hardware other than the mcu.

Cannot find more about this project, seems like website is down:
http://www.eevblog.com/forum/testgear/ (http://www.eevblog.com/forum/testgear/)$20-esr-lcr-transistor-npn-pnp-mosfet-meter/msg234473/#msg234473

Title: Re: $20 LCR ESR Transistor checker project
Post by: Flump on April 18, 2014, 08:32:35 pm
I really want to get an esr meter that can test in circuit
and also a transistor tester/semiconductor tester

but there is so many versions of these now i dont know what to get lol
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 18, 2014, 10:23:39 pm
I really want to get an esr meter that can test in circuit
and also a transistor tester/semiconductor tester

The ESR in-circuit measurement was added in the firmware versions 1.10k and 1.12m . We (Karl-Heinz and myself) encourage everyone to give us feedback about the in-circuit ESR feature.

Quote
but there is so many versions of these now i dont know what to get lol

It's like standing in front of the shelves full of detergents in the super market :-) You can DIY or buy a clone. My recommendations are ATmega328 and a classic text based LCD module. Some clones come with a nice box but most lack the hardware options.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Flump on April 19, 2014, 07:02:47 am
Thanks for the advice madires :)

I would like to buy one I am not good enough with electronics yet to make one

which would you say was the best out of the all in one ebay modules ?
i have a limit of about £30
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 19, 2014, 07:46:30 am
which would you say was the best out of the all in one ebay modules ?
i have a limit of about £30

There isn't any particular clone which is the best. Select the one which suits you most (test pads / textool socket / probe leads or whatever you prefer). Another thing to watch out for is the ISP header (unpopulated in most cases) for flashing new firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Towger on April 19, 2014, 06:21:56 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....
Yes, I am interested. I have been following this thread for ages now. The additional input protection along with the new support for in circuit ESR testing would make one very useful.
Are you going to design it through hole and/or SMT?
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on April 19, 2014, 07:45:26 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....

I'm intrested, too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BravoV on April 19, 2014, 07:47:21 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....

Vincent, I'm in, thanks !  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on April 19, 2014, 08:00:24 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....
Would be very interrested!
Will it use the 328 or an bigger mcu?, ref this:

I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.

Title: Re: $20 LCR ESR Transistor checker project
Post by: apelly on April 19, 2014, 08:07:52 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....
Yes please! I was going to make one myself, but that will take ages considering the rate at which I'm currently getting things done.
Title: Re: $20 LCR ESR Transistor checker project
Post by: KD0CAC John on April 19, 2014, 11:45:13 pm
I having wanting to build one of these also , but kinda waiting for one design settles , with some of the newer ideas coming on now , I just need to start ;)
So if you have room , put me on the list also ?
Thanks
John
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on April 21, 2014, 12:33:43 am
I want to make a nice board for these.
Anyone interested in the bare boards. For the cost of an envelope and international stamp....
Count me in for a couple.

From what I have seen a larger memory, decent resistors, programming header, crystal, battery, external power, backlighting and zif socket are all highly desirable features. As Madires mentioned going with a non standard display can add complexity for no benefit.
I highly recommend going with the display I have pictured, not only are they cheap, easy to source and replace but they look great.

I think the zif socket outside the enclosure works well also like a eprom programmer. Then insert a small pcb into the zif socket for smd devices, or wires for probes etc. Here is my idea I was thinking of, being that you can easily detach the display and it doesn't interfere with the main board.
I was going to make a modular sub board with the zif socket but later decided mounting everything from the zif is better.

(http://i62.tinypic.com/2wfi88i.jpg)

(http://i42.tinypic.com/2eulyqg.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 21, 2014, 01:27:32 am
From what I have seen a larger memory, decent resistors, programming header, crystal, battery, external power, backlighting and zif socket are all highly desirable features.

And a bunch of options:
- PWM backlight (just hardware)
- 2.5V voltage reference (if not using a MCP1702 or something similar as voltage regulator)
- protection relay (for discharging caps)
- high voltage Zeners (up to 50V DC, boost converter, requires 2 dedicated test pins)
- frequency counter (extra input)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Fluxed Matter on April 21, 2014, 03:50:35 pm

Anyone interested in the bare boards. For the cost of an envelope and international stamp....

How about local pickup? Or just drop it in the mail.


Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: jackryan315 on April 21, 2014, 08:45:57 pm


Anyone interested in the bare boards. For the cost of an envelope and international stamp....

count me in for a board or two.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on April 22, 2014, 11:47:15 am
What is the cost of a board and shipping to San Bernardino. What would you think the total cost of a completed board would be? When would this happen and when would you have a picture of a completed board?
Thanks
Title: Re: $20 LCR ESR Transistor checker project
Post by: Fluxed Matter on April 22, 2014, 01:50:22 pm
I think we should create a new thread about fe's new board so as not to derail this one.


Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: true on April 23, 2014, 12:33:47 pm
Anyone interested in the bare boards. For the cost of an envelope and international stamp....
I'm just a state over :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 23, 2014, 07:40:49 pm
Please use private mail for your "me too"!
Title: Re: $20 LCR ESR Transistor checker project
Post by: vindoline on April 26, 2014, 02:00:04 am
Hi Madires,

I've finally gotten around to finishing up my version of this great "transistor tester" project. I've flashed your latest firmware (1.12m) and the hardware/software seem to be working fine! The only components that I feel I can measure with any real accuracy/precision are resistors. I used a series of 1% metal film resistors from 1R to 1M, measured them with 2 different Fluke DMM's and then the new "transistor tester" The unit is remarkably accurate and agrees with the Flukes between 10R and 1M. Below 10 ohms the unit reads 5-10% high.

My question is about the inductance measurement. For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor. For higher value inductors, the measured value reads low (compared to the "nominal value" of the parts). I don't have another LCR meter to verify the actual inductance with, so the readings may actually be just fine. In any event, could you comment on the general measurement range and accuracy of the inductance measurement? Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 26, 2014, 02:15:22 am
i am still amazed at the capabilities of this project. it is by far my most useful piece of test equipment. working with geiger counter designs it has proven a huge time saver checking hv transistors, hv caps, and inductors to see if they are still alive (usually NOT! lol).

even my cheap $1 harbor freight dvms do pretty good with semiconductors so one thing i would love to improve is ability to measure lower value inductance and caps. even if it involves some minor hardware changes. i plan to dig into that pdf to get more up to speed on the theory but could also use some hints as to current ranges and how to improve lower value measurements.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on April 26, 2014, 03:15:29 am
Quote
For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor.

An inductor with infinite inductance is a resistor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 26, 2014, 03:45:43 am
I used a series of 1% metal film resistors from 1R to 1M, measured them with 2 different Fluke DMM's and then the new "transistor tester" The unit is remarkably accurate and agrees with the Flukes between 10R and 1M. Below 10 ohms the unit reads 5-10% high.

That make sense since an additional measurement method is used for resistors less than 10 Ohms. Does anyone else also got those high values for resistors < 10 Ohms? I'm testing the firmware with 3-4 different testers to detect any issues, but sometimes there are still some surprises.

Quote
My question is about the inductance measurement. For values of about 100 uH and below, the unit identifies the part as a low value resistor, not inductor. For higher value inductors, the measured value reads low (compared to the "nominal value" of the parts). I don't have another LCR meter to verify the actual inductance with, so the readings may actually be just fine. In any event, could you comment on the general measurement range and accuracy of the inductance measurement? Thanks!

The inductance measurement is quite limited by the maximum test current and the method used. It even runs the ATmega out-of-spec for some µs for low inductances. The supported range is roughly 100µH up to 1H and the resistance has to be less than 2kOhms. With a clock rate of 16MHz you'll get a small improvement (factor 2). Therefore the inductance measurement is just for checking the order of magnitude and not for measuring the exact value. Any LCR meter will give you more precise results.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 26, 2014, 03:58:20 am
even my cheap $1 harbor freight dvms do pretty good with semiconductors so one thing i would love to improve is ability to measure lower value inductance and caps. even if it involves some minor hardware changes. i plan to dig into that pdf to get more up to speed on the theory but could also use some hints as to current ranges and how to improve lower value measurements.

The k-firmware goes down to 30pF and the m-firmware down to 5pF. With the current hardware design and the implied measurement methods low value measurements aren't really feasable. The oscillator method (frequency counter) or the AC generator method (U and I) are suited much better for that purpose. That's something for a Tester+ ;-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: vindoline on April 26, 2014, 04:37:41 am
Madires, Thank you very much for the reply! It looks like my inductor measurement are right in spec then! The capacitor measurements I've made seem pretty accurate, certainly in the ballpark for the nominal value. The next thing I'll try are some transistors, FETs, etc.
Title: Re: $20 LCR ESR Transistor checker project
Post by: quantumvolt on April 26, 2014, 05:25:47 am
An inductor with infinite inductance is a resistor.

Since you have (absolute values) V/I = 2*PI*f*L wouldn't you say that - for frequency f greater than zero - an infinite L is an infinite effective impedance V/I - that is to say an open circuit (albeit with a 90 deg phase shift). For steady state DC, any inductor - infinitesimal or infinite - would (as I read it) behave as a zero effective impedance - a short.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 26, 2014, 09:06:07 am
The k-firmware goes down to 30pF and the m-firmware down to 5pF. With the current hardware design and the implied measurement methods low value measurements aren't really feasable. The oscillator method (frequency counter) or the AC generator method (U and I) are suited much better for that purpose. That's something for a Tester+ ;-)

yes, ive had good luck with "subtract 30pf" method but also working with uhf etc circuits it would be nice to get down in the range of 1 or 2 pf. the mid price meters do that w/o too much trouble so i guess low value inductors are the most desirable feature for me atm. since theres frequency counter function then maybe a simple inverter with switchable caps would do the trick. then its only a matter of some simple conversions. looks like its time to dig into the source.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on April 26, 2014, 10:01:40 am
Quote
For steady state DC, any inductor - infinitesimal or infinite - would (as I read it) behave as a zero effective impedance - a short.

And what's left is the serial resistance of an inductor.

So an inductor with infinite inductance will block any ac signal and let pass it the dc portion of the incoming signal.

Like a capacitor, in the opposite way.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on April 27, 2014, 03:54:06 am
I got one of these board from eBay for $20. It's amazingly useful--I primarily use it to identify transistors and verify the pinout.  I've run some tests on it for various values resistors, capacitors, inductors and voltage drop across some diodes. Attached are the results compared to a Fluke 187 multimeter, Brymen BM869 multimeter, and DE5000 LCR meter. The highlighted green columns are the "reference" columns that other values are being compared to.

* My board is marked as v 2.4 and is stock / as delivered with the Atmega168. It is running the 1.05k software.
* Transistortester resistance readings are within about 1% from 100 ohms - 1 Mohm. Low values have higher error. It doesn't look like it reads < .7 Ohms.
* Capacitance readings were generally close to the multimeter readings, but the DE5000 generally read much lower than the other meters
* Inductance couldn't be measured for the .8 - 1.6 uH inductors --it shows .7 Ohm resistance. Values for 10-
* Diode voltage drops read higher than the multimeters, but the Transistortester was able to produce a value while the multimeters could not

Testing notes:
* Capacitor readings were done at 1kHz on the DE5000 up to 100 uF and 100Hz for 2200 and 6800 uf Capacitors
* Red Led had a measured drop of 1.77V with 1mA, 2V with 20mA
* White led had a measured drop of 2.69V with 1mA and 3.27V with 20mA

I plan on updating the firmware when I get a programmer and possibly doing some of the hardware mods as previously suggested.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 27, 2014, 04:13:42 am
* My board is marked as v 2.4 and is stock / as delivered. It is running the 1.05k software.
* Transistortester resistance readings are within about 1% from 100 ohms - 1 Mohm. Low values have higher error. It doesn't look like it reads < .7 Ohms.

Please update to 1.10k (1.05k is about 15 months old). That version measures low value resistors down to 0.01 Ohms.
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on April 27, 2014, 12:24:44 pm
I have revision 2.2 of that board and comes with the 8MHz crystal. Too bad they removed it from newer revisions. Mine is bricked after I tried to update the firmware.  I tried using the MiniPro TL866A and the USBAsp but fails. I don't know if the processor is cooked or something with the fuses. I have some Atmega328P-AU to replace the Atmega168. My USBAsp has the warning: cannot set sck period. please check for usbasp firmware update problem so I'm trying to breadboard another USBAsp to program the original one. I feel that for every problem I fix I get two new ones :(
Title: Re: $20 LCR ESR Transistor checker project
Post by: gtroc71 on April 27, 2014, 01:00:41 pm
I have revision 2.2 of that board and comes with the 8MHz crystal. Too bad they removed it from newer revisions. Mine is bricked after I tried to update the firmware.  I tried using the MiniPro TL866A and the USBAsp but fails. I don't know if the processor is cooked or something with the fuses. I have some Atmega328P-AU to replace the Atmega168. My USBAsp has the warning: cannot set sck period. please check for usbasp firmware update problem so I'm trying to breadboard another USBAsp to program the original one. I feel that for every problem I fix I get two new ones :(


Hey mate I had the same sck period problem but the info at http://www.rogerclark.net/?p=702 (http://www.rogerclark.net/?p=702) worked for me if you have an arduino handy.
Best of luck!
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on April 27, 2014, 04:38:09 pm
No Arduino here, that's why I have to create a basic Arduino or a basic USBAsp to fix mine.
http://www.fischl.de/usbasp/ (http://www.fischl.de/usbasp/)
http://blog.apexelectrix.com/how-to-update-usbasp-firmwares/ (http://blog.apexelectrix.com/how-to-update-usbasp-firmwares/)
I have seen the solutions using the Arduino.
Now is breadboard time.
Thank you :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 27, 2014, 10:29:02 pm
that warning should be ignored. it has no effect on operation. its amazing how many have bricked their boards AND usbasp programmer thinking they had to update firmware. "if it aint broke dont fix it", even if you think it is because of that stupid message.
Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on April 27, 2014, 11:01:22 pm
* My board is marked as v 2.4 and is stock / as delivered. It is running the 1.05k software.
* Transistortester resistance readings are within about 1% from 100 ohms - 1 Mohm. Low values have higher error. It doesn't look like it reads < .7 Ohms.

Please update to 1.10k (1.05k is about 15 months old). That version measures low value resistors down to 0.01 Ohms.

Is there a place to submit features request?  I have a french made transistor tester, but the software has not been updated.  They do have a function to test opto-coupler.   On powerup, it shall detect if the opto-adapter is attached and so shall "mode" opto coupler testing.  Giving the CTR value accordingly.  Also is it possile to test MOSFET or IGBT driver chip, and those that are opto-isolated driver?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 28, 2014, 02:51:49 am
Is there a place to submit features request?  I have a french made transistor tester, but the software has not been updated.  They do have a function to test opto-coupler.   On powerup, it shall detect if the opto-adapter is attached and so shall "mode" opto coupler testing.  Giving the CTR value accordingly.  Also is it possile to test MOSFET or IGBT driver chip, and those that are opto-isolated driver?

We're limited to three probe leads and a maximum voltage of 5V. For the autodetection of an opto-coupler we would need 4 probes. The MOSFET/IGBT drivers create voltages around 10V which are too high for the ATmega. At the moment I don't see any way to add the features above. If you got an idea please let me know.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on April 28, 2014, 03:18:54 am
I put my AVR tester into a metal housing and I am getting wrong measured values of capacitors. What to do with that? Maybe a plastic housing would be better?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 28, 2014, 03:41:49 am
I put my AVR tester into a metal housing and I am getting wrong measured values of capacitors. What to do with that? Maybe a plastic housing would be better?

Just for values in the pF range or also for µF? How much are the values off? Have you connected the metal case to the tester's ground or is the tester completely isolated?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on April 28, 2014, 04:12:36 am
Just for values in the pF range or also for µF? How much are the values off?
I am getting some 50µF to 300µF readouts with test wires not connected to anything or sometimes when connected to a 300nF capacitor.
Have you connected the metal case to the tester's ground or is the tester completely isolated?
Yes, the metal case is connected to the tester's ground.
Well, this is strange. The fault appears only when simple non-switched PSU is used. When I use an industrial switched PSU, the problem never appears.
Semiconductor measurement is always correct.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 28, 2014, 04:49:55 am
Yes, the metal case is connected to the tester's ground.
Well, this is strange. The fault appears only when simple non-switched PSU is used. When I use an industrial switched PSU, the problem never appears.

Could you please remove the connection between the metal case and ground and check again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on April 28, 2014, 04:53:11 am
I will try it later...
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on April 30, 2014, 12:08:40 am
Hi guys,

I'm currently looking at : http://pages.ebay.com/link/?nav=item.view&id=171313859915 (http://pages.ebay.com/link/?nav=item.view&id=171313859915)
Is it any good and is the software upgradeable?
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 30, 2014, 12:37:24 am
as mentioned the ones with graphic lcd will never be up to date with latest firmware. and dont really show more info. i also have a feeling it will be more than $11 before bidding ends. there are many out there easily impressed by bling.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on April 30, 2014, 01:43:21 am
as mentioned the ones with graphic lcd will never be up to date with latest firmware. and dont really show more info. i also have a feeling it will be more than $11 before bidding ends. there are many out there easily impressed by bling.
Thanks your reply. Maybe it's better to wait for free-electron's board (whenever that may appear?) or look for an atmega328 with a character display as has been stated earlier in this thread.
Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: paulie on April 30, 2014, 04:30:09 am
personally i think its wise to stick with something compatible with original hardware. extra stuff dont hurt but its nice to take advantage of any innovatios cooked up by m and k. ie the recently added frequency counter which has just proven invaluable to me for measuring ultra low value caps and inductors (i did have to add an mb506 and 4040).

and if you are diy type dont forget you can throw together a quickie for less than $1 in parts:

Title: Re: $20 LCR ESR Transistor checker project
Post by: ecat on April 30, 2014, 09:33:37 pm
Moving away from the $1 range, I have a couple of MCP3424s (4 ch, 18bit ADCs + Vref) sitting here looking for a home. Do you think there would there be any benefit swapping one in place of the internal ADCs and changing the code to accommodate of course  :)

MCP3424 http://ww1.microchip.com/downloads/en/DeviceDoc/22088b.pdf (http://ww1.microchip.com/downloads/en/DeviceDoc/22088b.pdf)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 30, 2014, 10:48:54 pm
Moving away from the $1 range, I have a couple of MCP3424s (4 ch, 18bit ADCs + Vref) sitting here looking for a home. Do you think there would there be any benefit swapping one in place of the internal ADCs and changing the code to accommodate of course  :)

For some measurements an 18 bit resolution would be nice but the MCP3424 has some issues. It's really slow at 18 bits and can only use the internal 2.048V voltage reference. Therefore it would be only usable for high resolution measurments if the voltage is below 2V and if there are no timing constraints. The tester uses also the ATmega's analog comparator feature (taking the ADC pins as inputs for the comparator) and the ESR measurement performs exact timing of the internal ADC's S&H. You could add the external ADC in parallel and use it for more precise low voltage measurements, e.g. for resistors.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ecat on April 30, 2014, 11:01:38 pm
Moving away from the $1 range, I have a couple of MCP3424s (4 ch, 18bit ADCs + Vref) sitting here looking for a home. Do you think there would there be any benefit swapping one in place of the internal ADCs and changing the code to accommodate of course  :)

For some measurements an 18 bit resolution would be nice but the MCP3424 has some issues. It's really slow at 18 bits and can only use the internal 2.048V voltage reference. Therefore it would be only usable for high resolution measurments if the voltage is below 2V and if there are no timing constraints. The tester uses also the ATmega's analog comparator feature (taking the ADC pins as inputs for the comparator) and the ESR measurement performs exact timing of the internal ADC's S&H. You could add the external ADC in parallel and use it for more precise low voltage measurements, e.g. for resistors.

Thanks for the info. Sounds like more trouble than it's worth with the MCP3424.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on May 02, 2014, 12:19:11 am
Yes, the metal case is connected to the tester's ground.
Well, this is strange. The fault appears only when simple non-switched PSU is used. When I use an industrial switched PSU, the problem never appears.

Could you please remove the connection between the metal case and ground and check again.

So guys, there is no problem with the metal housing. The odd readouts are caused by some interference with the 230V power supply. The problem appears less if you use a switched power supply. The AVR tester's metal case should be connected to negative pole and you can put your hand on it to ground yourself, then it will be fine.


Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on May 05, 2014, 10:41:49 pm
What about free-electron's board as mentioned in this thread… Will it ever appear? If not I will go with one of the newer at328 boards from our chinese 'friends'.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on May 06, 2014, 04:30:00 am
What about free-electron's board as mentioned in this thread… Will it ever appear? If not I will go with one of the newer at328 boards from our chinese 'friends'.

Well most of us own at least one so I doubt anyone is in too much of a hurry.
But a nice upgradable board design that offers all the features would be nice.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on May 09, 2014, 09:48:37 pm
Could someone tell me what board this esr meter is based upon: http://m.youtube.com/watch?v=WjkYq4Auvk8 (http://m.youtube.com/watch?v=WjkYq4Auvk8) and where to look for the layout?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on May 10, 2014, 12:38:24 am
The Karl Heinz Kubbeler version is IMHO better.
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on May 10, 2014, 04:14:31 am
Intrax,
http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester)
It is in german, just let google translate it for you :)
All the information you need is there.
Title: Re: $20 LCR ESR Transistor checker project
Post by: simonmc on May 10, 2014, 07:49:36 pm
I received my version yesterday, i will post some pics but i will have to resize them.

 It has a 168 installed and is running v1.07 i believe. I have to say i'm very impressed and the unit will prove very useful to me. I did have some problems with my order, it seems the first one the seller sent, got lost and the seller posted out a second one to me. I don't know if the one that has just arrived is the first or second one though so i may end up with another one in the next couple of weeks!

I will replace the 168 with a 328 when i get the time and replace the reg and resistors with better items and add some better decoupling to the micro. The fitted zener seems to be a smt 4.3V one. Can anyone recommend a decent LDO with the same footprint as the mounted 7805?

The ZIF socket is not the best quality but it is usable and if it breaks i will replace with a 3M one. I de-soldered the LCD and added a socket so that it is removable. I also added some stand off's to act as feet. I still have to add the 6 pin ISP header.

As regards to the latest firmware, can you good people confirm i have the correct tool chain to compile and programme the device. I have Amtel studio 6.1 installed, extreme burner AVR, and will be ordering a couple of the cheap ebay USB ISP devices that are on ebay. Is this all i need?

EDIT:- Added pics
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on May 10, 2014, 08:26:04 pm
I will replace the 168 with a 328 when i get the time and replace the reg and resistors with better items and add some better decoupling to the micro. The fitted zener seems to be a smt 4.3V one. Can anyone recommend a decent LDO with the same footprint as the mounted 7805?

A zener? If a standard zener is connected to PC4 please remove it. And in case you like to have a voltage reference replace the zener with a LM285 or LM4040 2.5V. I'd recommend to use the MCP1702 as LDO, even with the different pinout. It works great and you don't need the external voltage reference.

Quote
As regards to the latest firmware, can you good people confirm i have the correct tool chain to compile and programme the device. I have Amtel studio 6.1 installed, extreme burner AVR, and will be ordering a couple of the cheap ebay USB ISP devices that are on ebay. Is this all i need?

Atmel Studio is fine. Can't say anything about extreme burner AVR since i'm using avrdude. And for the programmer I'd get something like the Diamex ALL-AVR which does ISP, PDI and TPI (USB is compatible with AVRISP-MkII).
Title: Re: $20 LCR ESR Transistor checker project
Post by: simonmc on May 10, 2014, 09:39:22 pm
Quote
A zener? If a standard zener is connected to PC4 please remove it. And in case you like to have a voltage reference replace the zener with a LM285 or LM4040 2.5V. I'd recommend to use the MCP1702 as LDO, even with the different pinout. It works great and you don't need the external voltage reference.

It looks like a zener judging by its code (431, mounted just above and to the right of the micro in the second pic i posted) and is connected to PC4. Should i remove that part even though i dont have a reference or ldo on hand till i get to work?? Does this zener actually decrease the accuracy of the cct or does it do nothing at all?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on May 10, 2014, 11:21:05 pm
It looks like a zener judging by its code (431, mounted just above and to the right of the micro in the second pic i posted) and is connected to PC4. Should i remove that part even though i dont have a reference or ldo on hand till i get to work?? Does this zener actually decrease the accuracy of the cct or does it do nothing at all?

Hmm, could be a TL431. Are two pins shorted (cathode and ref)? A TL431 should be fine too. Though, we don't know it's accuracy (AFAIK you can get 2%, 1% and 0.5% types). It's all about the ADC's voltage reference. Either you got an accurate and stable 5V regulator or a proper external voltage reference. In the first case the tester assumes that 5V are 5.000V. In the latter case the tester uses the external voltage reference to calculate the offset of the 5V rail. For a 7805/78L05 you'll need the external voltage reference because the 78 is not accurate enough. The MCP1702 LDO for example has an accuracy of 0.4%. An external voltage reference with a poor accuracy will make the tester less accurate.
Title: Re: $20 LCR ESR Transistor checker project
Post by: simonmc on May 11, 2014, 12:15:46 am
looking at the datasheet it could very well be a TL431. Yes the cathode and ref pins are shorted.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Aragorn on May 17, 2014, 10:05:52 am
Is there a file download section here for the tester Pcb layouts? I just built the tester, would like to cleanup the project. Is anyone selling blank pcbs?

Thanks,
-d
Title: Re: $20 LCR ESR Transistor checker project
Post by: casinada on May 17, 2014, 11:42:05 am
Aragonrn,
There are many different versions of the tester as is discussed here:
http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester)
All the information can be found there.
Assembled and ready to go testers can be found on ebayy for as little as $13
There is a member of the eevblog that might make a board soon.
If you have questions after reading all the info available here and the site mentioned above, please come back and ask. :)

Title: Re: $20 LCR ESR Transistor checker project
Post by: Aragorn on May 19, 2014, 11:19:59 pm
Thank you, just ordered 2 from China. Not exactly what I wanted, but for the price, I couldn't build one myself.

-d
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on May 28, 2014, 10:00:46 am
Well I bought this one 4 days ago from Hong Kong and it arrived today, that's a record for me as normally Asian E-bay shipping to me on West Coast USA is 10-12 days.

 It's got the 328P avr chip in a socket. No ISP connector. I put a couple of npn, pnp, caps and it identified them all. Then I dug out my 250 .01% reference resistor and it read it as 249.5 so I'm pretty impressed.

I added four 1/2" nylon standoffs so it would sit flat and wrapped the 9 volt battery in plastic tape and rubber banded it to the back of the PCB. Who needs a case, not me.  ;)

http://www.ebay.com/itm/291041497713?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/291041497713?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)
Title: Re: $20 LCR ESR Transistor checker project
Post by: AintBigAintClever on May 31, 2014, 08:40:33 pm
If you want the latest manuals go to http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/) and download the tarball (I've not found a way of viewing the PDFs within the browser, this seems to be the quickest way). German and Russian manuals are available if you go up to the parent folder.

Well worth it if you think this is just a component tester. Extra goodies are a few button presses away :)

Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on June 01, 2014, 06:27:29 am
Hi all,

Which version does the high 20,000uF capacitor readings as stated by the below ebay listing

http://www.ebay.co.uk/itm/New-Transistor-Tester-Capacitor-ESR-Inductance-Resistor-Meter-NPN-PNP-Mosfet-/251210970850?pt=LH_DefaultDomain_0&hash=item3a7d5736e2 (http://www.ebay.co.uk/itm/New-Transistor-Tester-Capacitor-ESR-Inductance-Resistor-Meter-NPN-PNP-Mosfet-/251210970850?pt=LH_DefaultDomain_0&hash=item3a7d5736e2)

Many thanks

 :)

Also, could this version be upgraded to the latest version just by upgrading the processor  :-+ :--

http://www.ebay.co.uk/itm/NEW-TRANSISTOR-TESTER-NPN-PNP-MOSFET-THYRISTOR-DIODE-RESISTOR-CAPACITOR-METER-/261192428249?pt=LH_DefaultDomain_0&hash=item3cd0482ad9 (http://www.ebay.co.uk/itm/NEW-TRANSISTOR-TESTER-NPN-PNP-MOSFET-THYRISTOR-DIODE-RESISTOR-CAPACITOR-METER-/261192428249?pt=LH_DefaultDomain_0&hash=item3cd0482ad9)

as it only costs 12 dollars and has a socketed processor


 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 01, 2014, 07:07:50 am
Which version does the high 20,000uF capacitor readings as stated by the below ebay listing

Basically all do (theoretically up to 100mF).

Quote
Also, could this version be upgraded to the latest version just by upgrading the processor  :-+ :--

Any clone can be updated to the latest firmware, but only the ATmega328 can run the firmware with all features enabled. The other ATmegas with less flash memory got a stripped down firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on June 01, 2014, 07:24:22 am
Hi,

Thanks, what gets me unsure sometimes is when China/Hong Kong put mF instead of uF  :-/O

The first ebay copies state upto 20,000uF and others, the latest version say 100mF ( mili or micro  |O )

So in the last link a posted, upping the atmega8 to a atmega328 will give it all for £7 uk pounds plus a 328  :-+ :--

 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 01, 2014, 07:32:07 am
If you want the latest manuals go to http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/) and download the tarball (I've not found a way of viewing the PDFs within the browser, this seems to be the quickest way). German and Russian manuals are available if you go up to the parent folder.

Well worth it if you think this is just a component tester. Extra goodies are a few button presses away :)

Is it possible someone could simple post the english PDF manual or a direct link to the same? I don't seen to have a tarball compatible program to process that.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on June 01, 2014, 07:46:07 am
Hi,

The file is 1.5Mb, the file you want is 1.3Mb, but the limitation here is 1Mb.

7zip will open the file for you but you need two steps


1/ right-click on the example.tar.gz file and choose 7-Zip --> Extract Here from the context menu.
   
2/  then take the resulting example.tar file and the right-click again and choose 7-Zip --> Extract Here from the context menu.

If you download 7zip, make sure you don't get the one with hidden junk.

 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 01, 2014, 07:54:35 am
How do you make sure you did not get the one with JUNK? ???
Title: Re: $20 LCR ESR Transistor checker project
Post by: Retep on June 01, 2014, 08:04:51 am
Also, could this version be upgraded to the latest version just by upgrading the processor  :-+ :--

http://www.ebay.co.uk/itm/NEW-TRANSISTOR-TESTER-NPN-PNP-MOSFET-THYRISTOR-DIODE-RESISTOR-CAPACITOR-METER-/261192428249?pt=LH_DefaultDomain_0&hash=item3cd0482ad9 (http://www.ebay.co.uk/itm/NEW-TRANSISTOR-TESTER-NPN-PNP-MOSFET-THYRISTOR-DIODE-RESISTOR-CAPACITOR-METER-/261192428249?pt=LH_DefaultDomain_0&hash=item3cd0482ad9)

as it only costs 12 dollars and has a socketed processor
Looking at the photo this one seems to have a ATMega8 processor. The ATMega8 processor doesn't have enough memory for all the features in the later software versions. Personally I would spend a few dollars more to get one with a (socketed) ATMega328 processor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 01, 2014, 08:23:44 am
How do you make sure you did not get the one with JUNK? ???

 Same question. And does no one have the english manual pdf hosted somewhere?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on June 01, 2014, 08:35:50 am
Hi,

I've looked around and there are no reports of bloatware included with the install.

I use Linux, otherwise i would have installed it to see  :-/O When i did use windows, i used 7zip.

As for the Atmega8, yes i knew that, that's why i wondered if just popping in a 328 would be all that was needed, i was also thinking of using one of those cheep Clones, the arduino pro mini, changing the xtal to 8Mhz and adding a lcd which i have a few of  :-//

 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on June 04, 2014, 02:51:29 am
Can any of these ones do 'in circuit' testing of (discharged) capacitors or is there an easy fix possible so that they can?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 04, 2014, 03:02:46 am
Yes, the latest firmware brings a special function in menu.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on June 04, 2014, 04:10:04 am
Yes, the latest firmware brings a special function in menu.
Probably only working on atmega328… any link to a suitable model on ebay?  Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 04, 2014, 04:14:59 am
Yes, the latest firmware brings a special function in menu.
Probably only working on atmega328… any link to a suitable model on ebay?  Thanks.

Yep! Take any clone with an ATmega328 and flash the latest firmware. Both firmware branches (k and m) support in circuit capacitance and ESR checks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on June 04, 2014, 04:19:48 am
Yes, the latest firmware brings a special function in menu.
Probably only working on atmega328… any link to a suitable model on ebay?  Thanks.

Yep! Take any clone with an ATmega328 and flash the latest firmware. Both firmware branches (k and m) support in circuit capacitance and ESR checks.
Any ? I do like the graphics display's… ;D
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 04, 2014, 06:27:50 am
I am looking to buy this one:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281314227233&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

I need esr and capacitance measurment really often and i dont have money for a standard meter.

Can that version be updated with latest firmware?
And can you link some versions of firmware?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 04, 2014, 06:31:11 am
Any ? I do like the graphics display's… ;D

The Wumpus will get you  ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on June 04, 2014, 06:34:09 am
I am looking to buy this one:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281314227233&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

I need esr and capacitance measurment really often and i dont have money for a standard meter.

Can that version be updated with latest firmware?
And can you link some versions of firmware?

I guess you should ask the seller for the firmware source before buying those versions.. and find out if the icsp port is available for firmware uploads. ( I have newer found better pictures of these, showing the backside etc)
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on June 04, 2014, 06:50:33 am
I am looking to buy this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281314227233
 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281314227233)
The description reminds me of the last one I bought. 

'Latest Firmware' they said.
'What version is that?', I asked.
'The latest!', they said.

Turns out their definition of latest is 1.07k.  =/
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 04, 2014, 06:59:28 am
That version is just an example,i sent a message to seller.
But most likely i will have to buy standard socketed 328 version with 16x02 lcd

Somebody got a recommendation?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 04, 2014, 07:36:37 am
I am looking to buy this one:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281314227233&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

I need esr and capacitance measurment really often and i dont have money for a standard meter.

Can that version be updated with latest firmware?

That clone uses a graphics LCD which requires some custom firmware modifications.

Quote
And can you link some versions of firmware?

The latest and greatest is available at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/) ('trunk' for the k-firmware and 'Markus' for the m-firmware).
Title: Re: $20 LCR ESR Transistor checker project
Post by: AintBigAintClever on June 04, 2014, 08:15:23 am
I bought http://www.ebay.com/itm/190949271460 (http://www.ebay.com/itm/190949271460) which came with 1.10k firmware and the extra menus.

Main IC is a socketed 328.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on June 04, 2014, 08:27:54 am
did you take some pictures of its inside?
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 04, 2014, 05:12:03 pm
I bought http://www.ebay.com/itm/190949271460 (http://www.ebay.com/itm/190949271460) which came with 1.10k firmware and the extra menus.

Main IC is a socketed 328.

And off course seller does not send it to Croatia
Title: Re: $20 LCR ESR Transistor checker project
Post by: AintBigAintClever on June 05, 2014, 08:36:30 am
Try this one, then. Looks identical, my guess is that the insides will be, too. Croatia not on the postal exclusions this time.
www.ebay.com/itm/181109931348 (http://www.ebay.com/itm/181109931348)

Pictures of the inside of mine attached.

Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on June 05, 2014, 05:39:14 pm
looks good.. Strange that nobody adds the programming headers :(
Title: Re: $20 LCR ESR Transistor checker project
Post by: AintBigAintClever on June 05, 2014, 08:41:45 pm
Keeps the cost down I suppose. Why spend a few pence on a header when you can just NOT do it instead? Besides, if the IC is socketed it can be removed for programming.
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on June 05, 2014, 08:44:19 pm
the header I can solder myself, but the pinout.. holes.. are those really expensive ? :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 05, 2014, 09:11:09 pm
Try this one, then. Looks identical, my guess is that the insides will be, too. Croatia not on the postal exclusions this time.
www.ebay.com/itm/181109931348 (http://www.ebay.com/itm/181109931348)

Pictures of the inside of mine attached.

The cap for buffering AREF is missing (C1 in your case). By adding a 1nF ceramic cap you could stabilize the reference voltage of the ADC.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on June 06, 2014, 03:09:55 am
the header I can solder myself, but the pinout.. holes.. are those really expensive ? :)
Any links to a version including header?  O0
I have not seen one,  which one is best for in circuit testing ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 06, 2014, 04:07:49 am
the header I can solder myself, but the pinout.. holes.. are those really expensive ? :)
Any links to a version including header?  O0
I have not seen one,  which one is best for in circuit testing ?

 One problem attempting to use any ICSP is that the chip has external components wired to pins (I don't yet have a schematic so others would have to check for you) so they may very well interfere with the external programmer operation.

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 06, 2014, 06:45:30 am
the header I can solder myself, but the pinout.. holes.. are those really expensive ? :)
Any links to a version including header?  O0
I have not seen one,  which one is best for in circuit testing ?

Most clones without an enclosure got the pads for the ISP header (hidden below the LCD module).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 06, 2014, 06:50:11 am
One problem attempting to use any ICSP is that the chip has external components wired to pins (I don't yet have a schematic so others would have to check for you) so they may very well interfere with the external programmer operation.

No worries, it's designed to work fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 07, 2014, 07:52:26 am
My component tester is almost finished so I made a video. The front panel is under construction.
Universal component avr tester with ATmega328 (http://www.youtube.com/watch?v=NCSb3vqkbqA#)
Well, there are many such videos on youtube. Nothing new really.
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 08, 2014, 02:05:30 am
At end i bought this one
http://www.ebay.com/itm/281206556098?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/281206556098?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

It has socketed DIP Atmega328 so even if it has old firmware revision i can flash it to latest with my arduino
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on June 08, 2014, 11:50:56 pm
At end i bought this one
http://www.ebay.com/itm/281206556098?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/281206556098?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)
That looks the same at the last one I got but is a different seller.  Ask them what version of firmware it comes with.  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 09, 2014, 12:32:59 am
I asked and seller has no idea,he just verified that it has socketed Atmega328,so i will be able to update it if it comes with old version
Title: Re: $20 LCR ESR Transistor checker project
Post by: eevbstedt on June 09, 2014, 02:03:20 am
I asked and seller has no idea ...
Thanks for doing that and the feedback.  At least that seller is honest!  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 09, 2014, 04:34:21 am
Will any of these take measurements in circuit? I have been trying to follow the thread but get lost with all the jumping around. Is it that none of these will until you update the firmware? There are some of the responses that say to add parts. I am sure that you can't add the same parts to everyone of these or do you? I wish there was a simple answer as to which one to buy, then update like this, and add these parts and you will have a all working in circuit tester. Sorry but I get where I think I understand and then someone comes up with something else and then I am lost. I am just a nube and need some help.
Thanks for any answers.
Don http://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif (http://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif)
Title: Re: $20 LCR ESR Transistor checker project
Post by: AintBigAintClever on June 09, 2014, 04:52:00 am
The trouble with in-circuit testing is that you're not just testing the component, you're testing the component in parallel with all the other gubbins that's connected across the same pins. Whatever result you get, I don't think you can trust it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 09, 2014, 05:47:57 am
I think that only thing that you can measure in circuit is ESR of caps,hope that I am not wrong
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 06:00:39 am
Will any of these take measurements in circuit?

The current firmware (from the project's web site) supports in-circuit capacitance and ESR measurements.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 09, 2014, 06:08:23 am
Thanks for the replies. Now, which one would be a good low price one that can use the latest updates and how about someone showing some ways to do the update for the rest of us that are not sure how to do it. In my case I have not updated firmware in a while on anything even though I have several different units to do the updates. As I remember, it gets confusing as you have to get the computer to talk and recognize the updater and then there are several different programs to use and they are all different. A simple YouTube video for updating these cards would be great. I don't have a lot of money to just waste buying different ones until I find one that works, so suggestions would be great!
Thanks again.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 06:11:15 am
The trouble with in-circuit testing is that you're not just testing the component, you're testing the component in parallel with all the other gubbins that's connected across the same pins. Whatever result you get, I don't think you can trust it.

Of course the circuit around the cap will influence the result, but it's sufficient to get a ballpark figure. I've tested a lot of circuits while writing the code for the in-circuit ESR measurement of the m-firmware and in most cases the values were off by about 10% at maximum. I was a little bit suprised since I was expecting a larger difference.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 06:38:19 am
Thanks for the replies. Now, which one would be a good low price one that can use the latest updates and how about someone showing some ways to do the update for the rest of us that are not sure how to do it. In my case I have not updated firmware in a while on anything even though I have several different units to do the updates. As I remember, it gets confusing as you have to get the computer to talk and recognize the updater and then there are several different programs to use and they are all different. A simple YouTube video for updating these cards would be great. I don't have a lot of money to just waste buying different ones until I find one that works, so suggestions would be great!
Thanks again.
Don

Any clone with an ATmega328 and a 2*16 LCD module is fine. For updating the firmware you can use an inexpensive ISP programmer, even an Arduino. If possible please add an ISP header to the tester. Otherwise you would have to breadboard something, First, you download the current firmware, update Makefile and config.h to match your hardware and compile the firmware. AVR Studio or avr-gcc are recommended. Then you use the ISP programmer to flash the firmware including the EEPROM. I'm using the Diamex ALL-AVR with avrdude under Linux for example (just a simple 'make upload').
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on June 09, 2014, 07:13:16 am
If you need to update MAKEFILE and config.h that will stop me from updating because i am not really into microcontroller programming
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 09, 2014, 07:17:20 am
If you need to update MAKEFILE and config.h that will stop me from updating because i am not really into microcontroller programming

I will go you one better, I don't know what that is or how to do it! That is one reason I was hoping someone would make a video on it!
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 07:33:13 am
If you need to update MAKEFILE and config.h that will stop me from updating because i am not really into microcontroller programming

Karl-Heinz provides some compiled firmwares of the current version for standard setups in the SVN repo. Anyway, it's a good idea to learn about MCUs and tool chains.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 07:48:12 am
I will go you one better, I don't know what that is or how to do it! That is one reason I was hoping someone would make a video on it!
Don

There are tons of videos about programming ATmegas. Those also apply to the Transistortester. Please see
Programming AVR with Arduino (http://www.youtube.com/watch?v=_ZL-YNOH_jA#ws)
for an example with an arduino used as programmer.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 09, 2014, 08:03:16 am
Thanks for the replies. Now, which one would be a good low price one that can use the latest updates and how about someone showing some ways to do the update for the rest of us that are not sure how to do it. In my case I have not updated firmware in a while on anything even though I have several different units to do the updates. As I remember, it gets confusing as you have to get the computer to talk and recognize the updater and then there are several different programs to use and they are all different. A simple YouTube video for updating these cards would be great. I don't have a lot of money to just waste buying different ones until I find one that works, so suggestions would be great!
Thanks again.
Don

Any clone with an ATmega328 and a 2*16 LCD module is fine. For updating the firmware you can use an inexpensive ISP programmer, even an Arduino. If possible please add an ISP header to the tester. Otherwise you would have to breadboard something, First, you download the current firmware, update Makefile and config.h to match your hardware and compile the firmware. AVR Studio or avr-gcc are recommended. Then you use the ISP programmer to flash the firmware including the EEPROM. I'm using the Diamex ALL-AVR with avrdude under Linux for example (just a simple 'make upload').

What fuse byte values does your project use? The firmware does not include that information, most likely embedded in the makefile?

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 09, 2014, 08:13:57 am
What fuse byte values does your project use? The firmware does not include that information, most likely embedded in the makefile?

Yep, the Makefile supports several ATmega types in different configurations. Basically the default values are used and just the clock source and clock divider need to be changed.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 09, 2014, 10:14:04 am
Here is schematic and PCB of my version of component tester. (http://youtu.be/NCSb3vqkbqA)
I use the firmware made by Karl Heinz Kübbeler.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 09, 2014, 11:18:55 am
Thanks for the schematic.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 10, 2014, 10:25:57 am
Well, I made just some minor changes. Karl Heinz Kübbeler has the credits, he has done the whole job.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimjam on June 12, 2014, 04:00:31 am
Here is schematic and PCB of my version of component tester. (http://youtu.be/NCSb3vqkbqA)
I use the firmware made by Karl Heinz Kübbeler.
Thank you! Can you tell me:

- What software did you use to draw the diagram and create the PCB layout?
- a noob question: how did you then create the PCB?
-  What are the differences / advantages does this have vs the $20 Chinese version?

This looks like it's going to take a looooong time to create, from doing the PCB, buying the parts etc.... The parts alone will cost far more than $20 :) Probably cheaper to buy a real LCR meter, although this seems cooler :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 12, 2014, 11:07:06 am
Thank you! Can you tell me:
A) - What software did you use to draw the diagram and create the PCB layout?
B) - a noob question: how did you then create the PCB?
C) -  What are the differences / advantages does this have vs the $20 Chinese version?

D) - This looks like it's going to take a looooong time to create, from doing the PCB, buying the parts etc.... The parts alone will cost far more than $20
A) I used Eagle Version 5.11.0 from http://www.cadsoftusa.com/eagle-pcb-design-software/?lang=en (http://www.cadsoftusa.com/eagle-pcb-design-software/?lang=en)
B) It was made at my university in semi-professional way. I paid for it.

C) You can use a single layer PCB. Two types of LCD connectors are possible. There is added a reset button and a status LED, that indicates that the MCU is alive even if LCD is wrong or absent. You can use a 7V to 15V ac adaptor and there is an ovevoltage protection. On the other hand, my version needn't be neccesarily better than the Chinese one, I just built it according to my needs.

D) Well, it took a long time, but it is my hobby. Somebody gave me that metal housing and old LCDs so I did not have to pay for them.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on June 12, 2014, 11:09:41 am
Probably cheaper to buy a real LCR meter, although this seems cooler :)
I already have that CEM DT-9935. http://www.eevblog.com/forum/testgear/cheap-lcr-meter-cem-dt-9935/ (http://www.eevblog.com/forum/testgear/cheap-lcr-meter-cem-dt-9935/)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Richard Crowley on June 16, 2014, 03:40:43 pm
I apologize that I didn''t slog through all 495 previous posts in this thread.
But I just received a kit from an Ebay vendor and at first inspection, it looks good.
However, there is no documentation, even a schematic diagram.
Is the board layout and schematic diagram available online somewhere?
A quick Google search didn't reveal anything promising.

I am going to be asking the  Ebay vendor also, but they appear to sell everything from soup to nuts and they don't appear to be much into electronics.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 16, 2014, 09:22:15 pm
However, there is no documentation, even a schematic diagram.
Is the board layout and schematic diagram available online somewhere?
A quick Google search didn't reveal anything promising.

You'll find the official documentation at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/) (select the directory and click "Download GNU tarball"). The clones vary in their layouts, but mostly follow the schematic in the documentation.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 16, 2014, 09:49:27 pm
New features in the current k-firmware:
- support of encoder with push button for the UI
- support of graphical 128x64 LCD module based on ST7565
- frequency measurement
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on June 16, 2014, 11:42:01 pm
Nice!

I was looking to add support for Nokia's 84x48 gLCDs (PCD8544 based). Those modules are really cheap. I guess it will be easier now.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Richard Crowley on June 17, 2014, 06:55:21 am
You'll find the official documentation at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/) (select the directory and click "Download GNU tarball"). The clones vary in their layouts, but mostly follow the schematic in the documentation.

Thank you, madires.   :-+

There is some difference between my board and the official schematic.
I am creating an "as built" schematic of my variant. 
Is there a wiki or something for this product where I can post it?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 17, 2014, 07:04:18 am
I am creating an "as built" schematic of my variant. 
Is there a wiki or something for this product where I can post it?

I'd suggest to post it here or to send it to Karl-Heinz (please see the first page of the documentation for his email address).
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimjam on June 17, 2014, 11:13:26 pm
slightly off topic.... how did you create your PCB, madires? I downloaded your schematic + pcb layout, but as a noob, I am wondering what's the best way for me to create the PCB. I can go the whole shebang with getting a photoresist pcb, UV lamp, etchant etc, and I might use it again in the future.... but I'm curious how other people do it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on June 17, 2014, 11:53:55 pm
They order it from places like the ones mentioned in the cheap PCBs for low volume thread (http://www.eevblog.com/forum/manufacture/cheap-pcbs-for-really-low-volume/).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 18, 2014, 01:01:33 am
slightly off topic.... how did you create your PCB, madires? I downloaded your schematic + pcb layout, but as a noob, I am wondering what's the best way for me to create the PCB. I can go the whole shebang with getting a photoresist pcb, UV lamp, etchant etc, and I might use it again in the future.... but I'm curious how other people do it.

Since I already own all the tools I make PCBs myself but if I'd have to buy everything new I'd consider one of those inexpensive PCB services. I can't make vias or print nice soldermasks and silkscreens. In the TransistorTester thread of the microcontroller.net forum some people are organizing a centralised buying from time to time. For you, down under, a PCB service in China could be a good choice.

BTW: Regarding the schematic, it might be better to have D0-D3 of the LCD module floating instead of the ground connection. As I just learnt in another thread the data lines are pulled up internally by the module.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimjam on June 18, 2014, 11:06:39 pm
How much work is it to make your own pcb? Do you consider it a big deal / a full day project? But even so, it beats waiting for 2 weeks. There's also that PCB printer that Dave was showing from CEBIT....
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on June 19, 2014, 12:42:05 am
So with my current process, I'm at about an hour per a panel including cleanup. I have the gear to make double-sided panels of A4 size. Then it's cutting, drilling the holes and s.o. which adds another 20 minutes. I'd say that's pretty fast.

Still I don't think it's worth it, most of the time. Even if you earn exceptionally little, making a panel is about 25$ total in time and material. About the same that DirtyPCB charges. But with them, you get it without lifting a finger and with much better quality. Making your own boards means making a lot of mess and keeping supplies around the house. Cleaning up the former is annoying work. I like my day job much much better. So I'd charge much more for an hour of PCB making, than just what I make at my day job. Storing the supplies is also annoying and takes up considerable space, even further adding to the perceived costs of board making. And on top of that, you have to design the boards more carefully than you otherwise would. You can't use that fine a trace, that many vias and so on.

The only argument for make your own PCBs is: "But I get my boards faster that way". It's not a strong argument though, because let's face it:
You rarely have all the parts, you need at hand. You'll almost always have to wait for a mail order of something - you might as well spend that time waiting for components and ordered boards.

Bottom line: Only sadist or very very time pressed people manufacture PCBs at home.
Title: Re: $20 LCR ESR Transistor checker project
Post by: senz_90 on June 19, 2014, 04:54:52 am
Sorry for my ignorance, I am really new on this microcontroller things, please bear with me. This project looks like will give me a good experience to begin about microcontroller. I have read several article and download it from german site and another site, since my mother's language is not english I am getting hard to understand how to modify the source code Makefile with compiler software. So let's the question begin :

1. If I am gonna use 16x2 lcd and english language with my tester, what is word that I need to change from makefile with compiler?
2. If I am gonna use Atmega168, how to set the fuse bit with kazama software? And If I wanna use Atmega328, how to set it?
what If I wanna use internal clock like 8Mhz? or external crystal 8Mhz? I have read several guide about fuse bits but I am really confuse. I hope someone wanna help me with some picture and I am really appreciated it.

Thank you


Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on June 19, 2014, 06:27:00 am
Hi,

This will help a little with understanding fuses


 :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 19, 2014, 07:48:44 am
1. If I am gonna use 16x2 lcd and english language with my tester, what is word that I need to change from makefile with compiler?

UI_LANGUAGE = LANG_ENGLISH
Support for a 16x2 LCD module is set by default.

Quote
2. If I am gonna use Atmega168, how to set the fuse bit with kazama software? And If I wanna use Atmega328, how to set it?
what If I wanna use internal clock like 8Mhz? or external crystal 8Mhz? I have read several guide about fuse bits but I am really confuse. I hope someone wanna help me with some picture and I am really appreciated it.

You can get the fuse bits from setup.mk for the different ATmegas and clocks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on June 28, 2014, 08:35:15 am
I am new here and also a newbie for electronics. I got mine today from ebay. It is with Atmel Mega328p AU chip, it impressed me with all SMD components and even with a Tantalum capacitor!
However, they failed to acknowledge Karl-Heinz K"ubbeler, madires and everyone else who contributed to the firmware design.

The seller claimed it is 2014 "latest" version. However when started the program, it showed:
"Transistor Tester V2.1". Wondering what exactly firmware it is running.

ALso, I am planning to upgrade the firmware anyway to the newest version using the ISP port, I am actually wondering what version of LCD should I use? Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: g***! on June 28, 2014, 09:26:15 am
Look at post 498....my board was identical to yours , worked for me1
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on June 28, 2014, 10:54:24 am
Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: at2marty on June 29, 2014, 01:49:20 am
I've read quite a bit about this project and am in the early stages of adapting it with a few minor modifications.  For the most part, most of what I plan will remain the same, but I chose to use an ATMega1284p so that I could do a few other things with it.

Perfect timing :-) Karl-Heinz has started to work on an  ATmega324/644/1284 version.

O.K. I'm finally ready to get back to this project.  I do have a few questions though.

I have downloaded the latest tarball, and started poking around a bit.  I'm assuming that the latest source for the project is in the Software/trunk directory, is that correct?  What is the difference between the stuff in the Markus directory and the tags directory?

In the Doku/tags directory, is there an easy way to translate the changelog.txt file from German to English?

Finally, I still would like to use an ATMega 1284p for my build.  Has a schematic or board layout been done or is work in progress with this?  If not, I am willing to do this and contribute to the project.  I personally prefer through hole, so that's how I would do it.  I don't want to start on it if someone else is already doing the work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 29, 2014, 01:55:26 am
I've had my tester for about a month now. Yesterday I decided to pull the 328p from it's socket and install it in my USBasp programmer with ZIF adapter with the intent of reading the flash and fuse bytes using AVRDUDE so that I could make a duplicate/spare controller.

 On trying I was only able to obtain a HEX file that was empty. On looking at the lock bits (0x3C) and checking with the datasheet it seems the chip is disabled from reading it's flash contents and prevented from being able to change the lock bits.

 I wonder if anyone else has checked there controller chip to see if it's common for the seller/maker to 'protect' the firmware?


http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
Title: Re: $20 LCR ESR Transistor checker project
Post by: at2marty on June 29, 2014, 02:11:17 am
I've had my tester for about a month now. Yesterday I decided to pull the 328p from it's socket and install it in my USBasp programmer with ZIF adapter with the intent of reading the flash and fuse bytes using AVRDUDE so that I could make a duplicate/spare controller.

 On trying I was only able to obtain a HEX file that was empty. On looking at the lock bits (0x3C) and checking with the datasheet it seems the chip is disabled from reading it's flash contents and prevented from being able to change the lock bits.

 I wonder if anyone else has checked there controller chip to see if it's common for the seller/maker to 'protect' the firmware?


http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

Hmm... I can't help you much as far as getting a good HEX image of what is on the chip.  You can change the lock bits back to default by writing a new program to it, but it will erase anything that is currently on it.

I would suggest downloading the latest firmware and use it as your spare.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 29, 2014, 02:37:08 am
Quote
I would suggest downloading the latest firmware and use it as your spare.

 Thanks.

 I looked into that but I don't have a proper unpacker/decompressor program on my new Win 8.1 machine and just didn't want to proceed with looking for one. If someone could provide a direct link to a hex file that would be cool, otherwise no big deal just something I was playing with. If unit ever dies I would have no problem with spending another $20 for a new one as it's that cool of a device.

Title: Re: $20 LCR ESR Transistor checker project
Post by: at2marty on June 29, 2014, 03:55:43 am
Quote
I would suggest downloading the latest firmware and use it as your spare.

 Thanks.

 I looked into that but I don't have a proper unpacker/decompressor program on my new Win 8.1 machine and just didn't want to proceed with looking for one. If someone could provide a direct link to a hex file that would be cool, otherwise no big deal just something I was playing with. If unit ever dies I would have no problem with spending another $20 for a new one as it's that cool of a device.

I would be willing to do that for you, but I don't think that it's right for me to distribute the file from a source other than the official site.  I believe that you might be able to download it directly from the official site by going to http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) and save the hex file from there.

I'm not familiar at all with Windows 8.1, but I do know that a program called 7zip will unpack a tarball.  I would suggest downloading it from the official website http://www.7-zip.org/ (http://www.7-zip.org/)

If you choose 7zip, you will have to extract it twice.  The first time you will end up with a filename.tar .  Extract filename.tar to actually get the real file.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 29, 2014, 04:52:33 am
Thanks for the info, but it's more complex and bother then I'm willing to go through.

Title: Re: $20 LCR ESR Transistor checker project
Post by: Macbeth on June 29, 2014, 05:04:02 am
Thanks for the info, but it's more complex and bother then I'm willing to go through.
...This has made my head explode  |O
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on June 29, 2014, 06:00:48 am
Thanks for the info, but it's more complex and bother then I'm willing to go through.
...This has made my head explode  |O

I'd have that looked at if I was you.  ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 29, 2014, 06:45:44 am
I have downloaded the latest tarball, and started poking around a bit.  I'm assuming that the latest source for the project is in the Software/trunk directory, is that correct?  What is the difference between the stuff in the Markus directory and the tags directory?

Yes, the current k-firmware version under development is in the trunk directory. The tags directory contains old k-firmware releases and the Markus directory got the m-firmware releases.

Quote
In the Doku/tags directory, is there an easy way to translate the changelog.txt file from German to English?

Some online translation tool? Please ask Karl-Heinz if he would also provide an English version.

Quote
Finally, I still would like to use an ATMega 1284p for my build.  Has a schematic or board layout been done or is work in progress with this?  If not, I am willing to do this and contribute to the project.  I personally prefer through hole, so that's how I would do it.  I don't want to start on it if someone else is already doing the work.

AFAIK there's no ATmega 1284 based PCB yet and I'm sure that Karl-Heinz would put your contribution into the repo.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on June 29, 2014, 10:56:21 am
Interesting project!
I just needed to repair a Sansui AU-6500 amplifier that had lots of bad transistors so I had to breadboard something to test them. I'm definitely building this!
So really, we should make a pcb and declare it "official" (with the original designer's permission of course) and stop supporting the Chinese. Plus, it would be a good exercise in building something and you get to learn stuff on the way. Maybe a group buy for PCBs? Double sided.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on June 29, 2014, 11:08:25 am
Quote
stop supporting the Chinese.

Hurting someone should never be the goal until you get something out of it.

Do things because it is good for you. Not because it is bad for others.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on June 29, 2014, 12:16:00 pm
I should have been more elaborate in my statement. The thing is that people want it fast and cheap. I didn't mean to hurt any race whatsoever, I was just addressing the plethora of cheap electronics made with crappy parts that are coming out of Asia. Even thou they "work" out of the box I don't think that it's good overall to stimulate the Asian market while the local producers are complaining about lack of income/customers. I'm more of a "keep it in the family" guy and I don't really like the "it's kind of working and it's cheap" strategy that the Asian market deployed over the whole world. Once again, I stress to mention that I don't have anything with Asian people. My only problem is that they "lure" everyone with cheap, low quality stuff. Sure, there are some sellers that found a good balance and I salute them, but since they rip off a design, use cheap parts and make money out of it isn't something I applaud them for.
I didn't mean to cause no harm and hope we don't get off topic.
Once again, I stress that we should make a sort of "official" pcb that we could build ourselves :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on June 29, 2014, 01:10:07 pm
In the U.S. some people say to not buy from Asia but to buy Made in the USA. If you take a look at a majority of things marked made in the USA you will see it was made in Asia and or Mexico and just remarked made in the us and the local company is making a huge profit. I buy a lot of my remote control equipment direct from China as I don't have the money to give to large local company's for their CEO's to have large home's. I can buy the same item in the US for around 4 times what is costs me shipped from China or buy 4 time the equipment and enjoy it for the same cost. Either way, no one in the usa gets a job from it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on June 29, 2014, 07:11:38 pm
Quote
while the local producers are complaining about lack of income/customers.

They can always provider a better product / service at a lower price to win back customers.

I mean, that's competition. No amount of proping up does anyone any favor over the long term.
Title: Re: $20 LCR ESR Transistor checker project
Post by: nessatse on June 29, 2014, 07:20:18 pm
Here is my take on the tester that fits into the 'standard' 50mmx50mm form factor. I'll be sending the pcb for fab this week hopefully, which means another 4-6 weeks before I get to put it all together.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on June 29, 2014, 09:37:28 pm
So really, we should make a pcb and declare it "official" (with the original designer's permission of course) and stop supporting the Chinese. Plus, it would be a good exercise in building something and you get to learn stuff on the way. Maybe a group buy for PCBs? Double sided.

You don't have to reinvent the wheel ;) In the project's thread at the microcontroller.net forum you'll find several PCB layouts, and some people are organizing group buys from time to time. But I haven't seen any PCB with all the hardware options included yet.
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on June 29, 2014, 09:40:05 pm
free_electron was going to design a pvb.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torr032 on July 01, 2014, 10:11:26 am
I am from Europe and I would rather buy something from China then from the USA because U.S terrorize the whole world with their military army by attacking other countries.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on July 01, 2014, 10:55:29 am
I am from Europe and I would rather buy something from China then from the USA because U.S terrorize the whole world with their military army by attacking other countries.

 Well I've always said that people should always vote with their wallets.

Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 01, 2014, 12:57:20 pm
I am from Europe and I would rather buy something from China then from the USA because U.S terrorize the whole world with their military army by attacking other countries.

Why wouldn't you buy it from Europe instead? :)

On topic:
I worked a bit to make a through hole pcb for this project, by adding a relay for protection from charged capacitors, and a dc-dc converter for Zener measurement. I saw some designs that had that but I don't like to solder smd, at least not yet. And I want to socket the 328. I might be building on a board that was made available by a user on this thread but I don't know if I can keep it single sided. If not than I'll scrap it and make it double layer.

Offtopic:
I said it before and I'll say it again:
Economic health is maintained by each and one of us. The flow of our personal cash (yes, even the 20$ for a LCR meter) dictates the future of our country's/region's economy.
You complain that something made in the US/EU costs 2-3 times what it costs in Asia, but you don't think that the money that you give for that product comes back to you one way or another. It stays in your market. It doesn't leave the country. You buy a LCR meter from someone, he buys something else from your company etc.
 You want to buy something cheap from Asia, yet you demand a larger salary from your company. Basically you're a sink hole :)
Yes, it's tempting to buy something cheap from somewhere else but I guess that the main problem is financial education.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torr032 on July 01, 2014, 09:18:52 pm
Sure, I would certainly rather buy something from Germany then from China if it is the same price. But that is hard to find, almost every product that you can not find in your local stores, it is hard to beat the chinese with the product price + shipping costs. I heard that more than half of the world production of everything is coming from China, so why to buy something from the resellers at the higher price if time is not an issue and you can wait for the postman.
Also they are growing in the product quality and are able to manufacture good quality devices on their own.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 01, 2014, 09:26:50 pm
Yes, but by that standard, you are basically lowering the quality of life of your own country on the long run. I mean, basically you are asking your own country's sellers of the same items to work for the same money that the people that are selling the items from Asia are working for. I mean, indirectly you are condemning yourself in the future to the same grim quality of life that Asian people working in obscure factories are having. That's simple logic. You can't have items that cheap and still get payed a good amount of money every month.
Think on the long run, after Asia get a huge load of money from the rest of the developed parts of the world, and let's assume that that money gets distributed among the Asian people, they will no longer want to work for the amount that they are working for. They will have your money and they won't need to work for less. So this way you are increasing their quality of life and at the same time you are lowering yours.
Please, don't replay again with "but it's cheaper" :)

Of course this applies for stuff that you can get locally. If there's something that you need and you can only find it there...well, that's their gain, and is good for them.
Title: Re: $20 LCR ESR Transistor checker project
Post by: torr032 on July 01, 2014, 10:53:33 pm
Production is what matter. Now you can buy everything except food on the internet, so the trade business is not profitable as it was before.

China is fine for me, they don't use money for bombarding other countries or to create crisis in the world. People work hard so they could escape from poverty, buying chinese goods for me is some sort of a patriotism, hey lets spread the world wealth more evenly in the world. While some ppl on the world are dying from hunger it is not fair that some countries especially western ones are that rich.
I am also buying on the internet since I know how to do that. Buying chinese goods in local shops is for ppl that don't know how to buy on net or when time matter.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 01, 2014, 10:59:26 pm
I worked a bit to make a through hole pcb for this project, by adding a relay for protection from charged capacitors, and a dc-dc converter for Zener measurement. I saw some designs that had that but I don't like to solder smd, at least not yet. And I want to socket the 328. I might be building on a board that was made available by a user on this thread but I don't know if I can keep it single sided. If not than I'll scrap it and make it double layer.

The latest add-ons are an input stage for frequency counting and a mechanical encoder (left/right/push button) for the UI. We'll keep you busy ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: all_repair on July 01, 2014, 11:48:31 pm
  If I were mainland Chinese, I would not mind and shall be very happy if you spend your time doing the $20 tester, which shall cost you maybe $50-$200, and maybe another $1000s of opportunity cost.  In no time, we can delegate the $20 tester away to you and focus on the much higher value stuff, and take more holidays without working so hard.   Maybe you can do a higher value kits or complete tester with all the latest?  This shall be more constructive.  If the price is reasonable, I shall buy and I don't think the mainlan Chinese mind buying from you as they do not mind buying expensive quality European, Japanese or American products, of course provided you want to sell to them.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 02, 2014, 06:12:42 am
I worked a bit to make a through hole pcb for this project, by adding a relay for protection from charged capacitors, and a dc-dc converter for Zener measurement. I saw some designs that had that but I don't like to solder smd, at least not yet. And I want to socket the 328. I might be building on a board that was made available by a user on this thread but I don't know if I can keep it single sided. If not than I'll scrap it and make it double layer.

The latest add-ons are an input stage for frequency counting and a mechanical encoder (left/right/push button) for the UI. We'll keep you busy ;)

Sure! Any documentation on the input stage? Need to sort through the Eagle library for that encoder but I can find some space on board.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 02, 2014, 06:24:58 am
Sure! Any documentation on the input stage? Need to sort through the Eagle library for that encoder but I can find some space on board.

Please download http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) and see ttester.pdf.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 02, 2014, 07:56:06 pm
Production is what matter. Now you can buy everything except food on the internet, so the trade business is not profitable as it was before.

China is fine for me, they don't use money for bombarding other countries or to create crisis in the world. People work hard so they could escape from poverty, buying chinese goods for me is some sort of a patriotism, hey lets spread the world wealth more evenly in the world. While some ppl on the world are dying from hunger it is not fair that some countries especially western ones are that rich.
I am also buying on the internet since I know how to do that. Buying chinese goods in local shops is for ppl that don't know how to buy on net or when time matter.

Sadly, most of the money that go to China is centralized into few groups that have government connections. Chinese people see little money from what you are sending in.
Then about the wealth of the country, it depends on the decisions made by the local powers.
So basically you are making a select group of people more wealthy, while the poor struggle. And guess where that money ends up being used? Military power!
Although I agree on helping people that need help, I'm firstly thinking of my own people :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 02, 2014, 08:07:27 pm
Sure! Any documentation on the input stage? Need to sort through the Eagle library for that encoder but I can find some space on board.

Please download http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) and see ttester.pdf.

I looked at it and will have a go tonight. Thank you
Title: Re: $20 LCR ESR Transistor checker project
Post by: dannyf on July 02, 2014, 09:31:35 pm
Quote
Sadly, most of the money that go to China is centralized...

Time for a reality check.

Title: Re: $20 LCR ESR Transistor checker project
Post by: senz_90 on July 03, 2014, 06:08:34 am
thank you madires, and Mark Heinz for this cool tester, I am still waiting my lcd come, and I am really new to this programming stuff. I hope I could make this, or maybe I would try basic program first to get familiar with this microcontroller things. once again thank you for you all make this cool stuff.

sorry for late reply. hahaha...
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on July 03, 2014, 06:30:17 am
I am new here and also a newbie for electronics. I got mine today from ebay. It is with Atmel Mega328p AU chip, it impressed me with all SMD components and even with a Tantalum capacitor!
However, they failed to acknowledge Karl-Heinz K"ubbeler, madires and everyone else who contributed to the firmware design.

The seller claimed it is 2014 "latest" version. However when started the program, it showed:
"Transistor Tester V2.1". Wondering what exactly firmware it is running.

ALso, I am planning to upgrade the firmware anyway to the newest version using the ISP port, I am actually wondering what version of LCD should I use? Thanks!

Thanks Madires and Mark Heinz for this amazing tool!
My 4 year old computer suffered from occasionally blue screen and I just used this meter and found several caps near the memory slots have way higher ESR than normal. I changed these bugs and now my computer is running strong again.
I guess my unit from Ebay is still running an old firmware. I am waiting for my ISP programmer to update it and I really expect to test the new on-circuit ESR function.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 03, 2014, 08:35:01 am
Sure! Any documentation on the input stage? Need to sort through the Eagle library for that encoder but I can find some space on board.

Please download http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/) and see ttester.pdf.

Should I use this package for the rotary encoder? ALPS_EC12E_SW You can find it in the Eagle library.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 03, 2014, 09:55:33 pm
thank you madires, and Mark Heinz for this cool tester, I am still waiting my lcd come, and I am really new to this programming stuff. I hope I could make this, or maybe I would try basic program first to get familiar with this microcontroller things. once again thank you for you all make this cool stuff.

You're welcome! The ATmega is a nice microcontroller for starters. My first one was the venerable 68HC11 and I still got the development board. BTW, his name is Karl-Heinz.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 03, 2014, 10:08:17 pm
Should I use this package for the rotary encoder? ALPS_EC12E_SW You can find it in the Eagle library.

That one is fine (got some EC11 or 12 in my drawer ;) ).
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 04, 2014, 08:29:15 am
I made my version of the project based on the ttester_eng110k.pdf schematic. It implements the 2.5 voltage reference, external crystal, TVS diode and relay protection of the inputs, but not the zener measurement. I'm able to get it to work with the 1.10k firmware with the relay removed. However, with the 1.12m version of the firmware, I either get no component found or some very large capacitance when no capacitor is attached. I'm assuming I haven't built the firmware correctly--any hints on what I need to adjust in the config.h or makefile? (Attached are the makefile and config.h I'm using when trying to build the 1.12m firware.)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on July 04, 2014, 09:14:10 am
A nice work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 04, 2014, 10:46:02 pm
Thanks!

Here are a couple more images of the layout.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 04, 2014, 11:48:19 pm
I made my version of the project based on the ttester_eng110k.pdf schematic. It implements the 2.5 voltage reference, external crystal, TVS diode and relay protection of the inputs, but not the zener measurement. I'm able to get it to work with the 1.10k firmware with the relay removed. However, with the 1.12m version of the firmware, I either get no component found or some very large capacitance when no capacitor is attached. I'm assuming I haven't built the firmware correctly--any hints on what I need to adjust in the config.h or makefile? (Attached are the makefile and config.h I'm using when trying to build the 1.12m firware.)

Which frequency does your crystal have? Based on the Makefile it's 16MHz. I haven't tested the m-firmware with the new input protection IC and TVS yet (lack of prototype with that IC). So it could be possible that it may cause some trouble, but mostly the crystal frequency and the fuse settings are misset. Regarding the relay problem I'd suggest to try increasing the delay time. The boards with relay protection I got use a quite small relay (Karl-Heinz got the same). A large relay might simply need some more time.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 05, 2014, 12:44:51 am
Which frequency does your crystal have? Based on the Makefile it's 16MHz. I haven't tested the m-firmware with the new input protection IC and TVS yet (lack of prototype with that IC). So it could be possible that it may cause some trouble, but mostly the crystal frequency and the fuse settings are misset. Regarding the relay problem I'd suggest to try increasing the delay time. The boards with relay protection I got use a quite small relay (Karl-Heinz got the same). A large relay might simply need some more time.
Thanks to Karl-Heinz and you for all your work on this project--it's a very nice contribution.

About my build:
* It's a 16 Mhz crystal
* The fuse values are L:f7 H:d9 E:fC
  * I'm using ProgISP with a cheap ebay programmer
* I get the same behavior with and without the relay installed--if I physically remove the relay, the TPs should all be disconnected, so it should have no effect, correct?

For the K version of the firmware, I used the built in RC oscillator (because I couldn't figure out if it supported a 16Mhz crystal) and didn't see a place to specify a relay in the makefile, so I had the relay removed. The K version works as expected.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 05, 2014, 02:04:53 am
About my build:
* It's a 16 Mhz crystal
* The fuse values are L:f7 H:d9 E:fC
  * I'm using ProgISP with a cheap ebay programmer
* I get the same behavior with and without the relay installed--if I physically remove the relay, the TPs should all be disconnected, so it should have no effect, correct?

For the K version of the firmware, I used the built in RC oscillator (because I couldn't figure out if it supported a 16Mhz crystal) and didn't see a place to specify a relay in the makefile, so I had the relay removed. The K version works as expected.

The fuse settings look fine and the missing relay shouldn't have any impact besides a small delay for the measurements. The k-firmware supports 16MHz too. I think, the next step is to check if the crystal oscillator is running. If it's not running please verify if the two caps between the crystal and ground got the correct value (18 or 22pF).
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 05, 2014, 03:09:13 am
The fuse settings look fine and the missing relay shouldn't have any impact besides a small delay for the measurements. The k-firmware supports 16MHz too. I think, the next step is to check if the crystal oscillator is running. If it's not running please verify if the two caps between the crystal and ground got the correct value (18 or 22pF).

The crystal is oscillating (see attached capture of the waveform). I can see the tester going through the test and updating the display.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Wh1sper on July 05, 2014, 03:19:40 am
Hi,
I did build one at my own with the great PCB made by Moritz A.
down side: expensive to build
plus: I have build it myself, by using the best components I could get. i.e. the high precision Reststors.
I understand the design, I have the schematics
But I bought a Chinese clone with graphic Display recently as second device.
Plus: CHEAP! and very nice build.
down side: no schematics, no precision resistors.
The measuring experience is by far not so exact as the German home build .
But for a quick qheck it is very useful.
So my thumb goes up for having 2, at least :-)
Also important is to have 2 different software versions.

Overall I like this project a lot.
Whenever one of the developers comes at my City, I own them a beer, or two :-)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 05, 2014, 03:29:19 am
The crystal is oscillating (see attached capture of the waveform). I can see the tester going through the test and updating the display.

Ok. Have you run the self adjustment? Prior to that please measure a film cap around 220nF up to 2µF three or four times. Does the tester identify resistors, diodes and transistors?
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 06, 2014, 07:46:37 am
The crystal is oscillating (see attached capture of the waveform). I can see the tester going through the test and updating the display.

Ok. Have you run the self adjustment? Prior to that please measure a film cap around 220nF up to 2µF three or four times. Does the tester identify resistors, diodes and transistors?

It doesn't recognize any components attached. While testing, the relay chatters (rapid on/off). Using the K firmware, there are just a few clicks of the relay during testing and it reports reasonable values.

As a side note: I originally used a BC547  to control the relay, but the transistor failed. The BC547 is rated to 100 mA and the relay is rated at 80 mA, so I didn't expect a problem. I replaced it with a 2n2222 which should hopefully be sufficient.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 06, 2014, 08:12:13 am
It doesn't recognize any components attached. While testing, the relay chatters (rapid on/off). Using the K firmware, there are just a few clicks of the relay during testing and it reports reasonable values.

That's strange! Could you please set the fuses to select the internal RC oscilllator (8MHz), recompile the m-firmware for 8MHz RC oscillator and try it again? BTW, could you also please sketch the circuit part driving the relay (PC4 and the voltage reference).
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 06, 2014, 08:13:25 am
I've been working on this project and I managed to get a single sided pcb with 5 wire-passes on the topside.
It has the Zener diode test and frequency test. Also it includes the left-right encoder with push-button.  There's a ZIF socket, pcb banana connectors and a daughter-board for the SMD stuff. You can just connect that if needed. Also there's a protection relay for charged caps. Also I've used 2 regulators, one for the IC and one for powering the extras. There's an ICSP connector as well. There is no pot for adjusting the contrast/light on the LCD, you will have to figure out the values for those things.
I still have some work to do on it, need to match holes for LCD support so it can be fixed with spacers. I will need to move some parts around to do that. Also I need to double check the footprint of some parts, and see what's available. The LCD should clear most parts.
This is a nice diy board that can be made at home. I will post the files after I'm finished with it.
Also I want to thank Mr. Madires as he guided me through this project.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 06, 2014, 10:01:52 am
I made the holes for the LCD. I used this datasheet:
http://www.adafruit.com/datasheets/TC1602A-01T.pdf (http://www.adafruit.com/datasheets/TC1602A-01T.pdf)
Seemed like a generic 2 line LCD.
Also now there are only 4 wire-passes on the top side. Rearranged the SMD pads a bit.
Any suggestions?
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 06, 2014, 10:15:55 am
I made the holes for the LCD. I used this datasheet:
http://www.adafruit.com/datasheets/TC1602A-01T.pdf (http://www.adafruit.com/datasheets/TC1602A-01T.pdf)
Seemed like a generic 2 line LCD.
Also now there are only 4 wire-passes on the top side. Rearranged the SMD pads a bit.
Any suggestions?
Nice layout. You may want to try to re-position the programming header so it's not under the LCD. With the LCD in place, it may interfere with the header. Also, it would be nice to reprogram it without having to remove the LCD. Your TO-92 packages seem to have different sized pads--you may want to make all of them the same with the larger pad sizes. You could also probably increase the pad sizes for the film capacitors.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 06, 2014, 10:18:35 am
It doesn't recognize any components attached. While testing, the relay chatters (rapid on/off). Using the K firmware, there are just a few clicks of the relay during testing and it reports reasonable values.

That's strange! Could you please set the fuses to select the internal RC oscilllator (8MHz), recompile the m-firmware for 8MHz RC oscillator and try it again? BTW, could you also please sketch the circuit part driving the relay (PC4 and the voltage reference).

I switched it to use the RC oscillator with fuses  L:e2 H:d9 E:fc and adjusted the makefile to use OSCILLATOR = RC, but get the same behavior. Attached is the schematic.
Title: Re: $20 LCR ESR Transistor checker project
Post by: nessatse on July 06, 2014, 08:28:29 pm
I made the holes for the LCD. I used this datasheet:
http://www.adafruit.com/datasheets/TC1602A-01T.pdf (http://www.adafruit.com/datasheets/TC1602A-01T.pdf)
Seemed like a generic 2 line LCD.
Also now there are only 4 wire-passes on the top side. Rearranged the SMD pads a bit.
Any suggestions?


Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 06, 2014, 09:31:29 pm
I switched it to use the RC oscillator with fuses  L:e2 H:d9 E:fc and adjusted the makefile to use OSCILLATOR = RC, but get the same behavior. Attached is the schematic.

Thanks! The schematic looks fine, my prototype with the relay protection has exactly the same driver. The only difference is the input protection IC and it got a 8MHz crystal, and a smaller relay. Since you mentioned the Makefile, have you also set FREQ = 8? What puzzles me, is that there's no flapping of the relay with the k-firmware. My next idea would have been to check Vcc in case the current draw of the relay causes the issue. Both firmwares drive the relay the same way, just with a slightly different timing regarding the measurement procedure. The MCU clock shouldn't have any impact on the relay anyway. I think we're overlooking something.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 06, 2014, 11:29:05 pm
I made the holes for the LCD. I used this datasheet:
http://www.adafruit.com/datasheets/TC1602A-01T.pdf (http://www.adafruit.com/datasheets/TC1602A-01T.pdf)
Seemed like a generic 2 line LCD.
Also now there are only 4 wire-passes on the top side. Rearranged the SMD pads a bit.
Any suggestions?
  • Your zener and frequency labels appear to switched.
  • You probably need a lot more clearance around the lcd mounting holes if you don't want screws/nuts shorting out your traces.
  • If this board is designed for home etching, I would suggest increasing your ground plane clearance a little
  • As radioFlash suggested, try increase some of your pad sizes and get the size consistent
* I used a 130 thou radius circle for the keep-out region around the LCD mounting holes. This gives just barely enough clearance for a 4-40 nut.
* I think you will have a clearance problem with the trim pot positioned under the LCD. To avoid that and allow adjustment with the LCD in place, you may wish to move the trim pot down a bit.
* The LCD has some metal tabs on the back which are bent to keep the LCD attached to the PCB. They project out about 1/10 inch. The LCD PCB will be about 430 thou above your PCB when mounted, so keep that in mind when thinking about clearance.

Attached is a photo of a 4-40 nut with the 130 tho radius keep-out region and an image of the backside of the LCD.
Title: Re: $20 LCR ESR Transistor checker project
Post by: bob808 on July 10, 2014, 08:29:26 am
I guess this is the best I could do.
It's hard as everything is tight, and as soon as I move some parts/traces I loose ground in some places and I don't want to add more wire passes. I think one could mount some non-conducting spacers on the back of the PCB for electrical isolation between the tracks and the nut. Also I think you could mount some taller spacers for the LCD but I think it should clear most of the parts.
If you wish I could post the Eagle files.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 11, 2014, 11:05:28 am
I switched it to use the RC oscillator with fuses  L:e2 H:d9 E:fc and adjusted the makefile to use OSCILLATOR = RC, but get the same behavior. Attached is the schematic.

Thanks! The schematic looks fine, my prototype with the relay protection has exactly the same driver. The only difference is the input protection IC and it got a 8MHz crystal, and a smaller relay. Since you mentioned the Makefile, have you also set FREQ = 8? What puzzles me, is that there's no flapping of the relay with the k-firmware. My next idea would have been to check Vcc in case the current draw of the relay causes the issue. Both firmwares drive the relay the same way, just with a slightly different timing regarding the measurement procedure. The MCU clock shouldn't have any impact on the relay anyway. I think we're overlooking something.

Good news--I was able to get the M firmware working. I switched from the cheap ebay "USB ISP" programmer to a genuine Atmel AVR ISP MkII programmer. The relay is working properly and values look reasonable. I may have been using the programmer software for the cheap programmer incorrectly. Using avrdude from the makefile to program the MCU has cleared up my problems.

Does the M version of the firmware support a rotary encoder yet?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 11, 2014, 10:12:09 pm
Good news--I was able to get the M firmware working. I switched from the cheap ebay "USB ISP" programmer to a genuine Atmel AVR ISP MkII programmer. The relay is working properly and values look reasonable. I may have been using the programmer software for the cheap programmer incorrectly. Using avrdude from the makefile to program the MCU has cleared up my problems.

That's great! One thing less I have to worry about :)

Quote
Does the M version of the firmware support a rotary encoder yet?

The next version will, I'm currently adding support for rotary encoders. Reading the encoder already works nicely using an ALPS EC11, but other encoders should also be fine (you just need to set the pulses per step/detent in config.h). Right now I'm working on using the extra user input to improve the UI. When running the PWM tool you can use the encoder to increase or decrease the PWM ratio in steps of 1% additional to the 5% steps of the push button. And I also have to get more encoders for testing the algorithm for reading the encoder signals, some crappy ones ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 13, 2014, 07:18:16 am
Just a quick update, you'll find 1.13m in the SVN now. And I'd appreciate any feedback on the rotary encoder's usability.
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 17, 2014, 07:05:12 am
 :) Hello everyone! Built this tester, works great, huge thanks to authors  :-+ Currently I use Mega8 with v1.04k and ordered Mega328, but encountered a problem - no compiled software available. I need version from Karl Heinz because i need to measure inductance. Can someone please post link to compiled version v1.11k ?  ::)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 17, 2014, 07:48:29 am
:) Hello everyone! Built this tester, works great, huge thanks to authors  :-+ Currently I use Mega8 with v1.04k and ordered Mega328, but encountered a problem - no compiled software available. I need version from Karl Heinz because i need to measure inductance. Can someone please post link to compiled version v1.11k ?  ::)

IIRC, the inductance measurement requires an ATmega with 16kB flash or more.
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on July 17, 2014, 09:26:18 am
:) Hello everyone! Built this tester, works great, huge thanks to authors  :-+ Currently I use Mega8 with v1.04k and ordered Mega328, but encountered a problem - no compiled software available. I need version from Karl Heinz because i need to measure inductance. Can someone please post link to compiled version v1.11k ?  ::)

IIRC, the inductance measurement requires an ATmega with 16kB flash or more.

Hence why he ordered a mega328?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 17, 2014, 09:41:46 am
Hence why he ordered a mega328?

Got it. :) It's http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) for the standard circuit.
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 17, 2014, 05:24:05 pm
Thanks  ;) Now I can test this great gadget
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 21, 2014, 05:49:26 am
Hi guys, decided to show it working. Have to say, it works like charm, considering that it's built in such a rude way  ;D I discovered interesting little glitch - you test diode, it displays it OK (symbol), but when you reverse connection, symbol gets messed up ??? Does someone have similar problem? I think it's connected either with LCD or EEPROM
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 21, 2014, 06:34:27 am
Hi guys, decided to show it working. Have to say, it works like charm, considering that it's built in such a rude way  ;D I discovered interesting little glitch - you test diode, it displays it OK (symbol), but when you reverse connection, symbol gets messed up ??? Does someone have similar problem? I think it's connected either with LCD or EEPROM

Cheap Chinese LCD? :) I'd think something went wrong while compiling or flashing the firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 21, 2014, 07:53:06 am

Hi guys, decided to show it working. Have to say, it works like charm, considering that it's built in such a rude way  ;D I discovered interesting little glitch - you test diode, it displays it OK (symbol), but when you reverse connection, symbol gets messed up ??? Does someone have similar problem? I think it's connected either with LCD or EEPROM

I noticed the glitched diode icon with the latest version of the K version of the firmware. I didn't have the issue with earlier versions.


Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 21, 2014, 02:54:16 pm
Cheap Chinese LCD? :) I'd think something went wrong while compiling or flashing the firmware.
Yeah, I bought it for around 3$  :D

I noticed the glitched diode icon with the latest version of the K version of the firmware. I didn't have the issue with earlier versions.
Sent from my iPhone using Tapatalk
Thanks for response, this means that I programmed MCU right
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on July 22, 2014, 03:29:35 am
Maybe you have mentioned it several times... What is the method used for measuring inductance, capacitance? I am thinking an LC meter spin-off.

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 22, 2014, 06:30:17 am
I noticed the glitched diode icon with the latest version of the K version of the firmware. I didn't have the issue with earlier versions.
Sent from my iPhone using Tapatalk
Thanks for response, this means that I programmed MCU right

Ok, I've reported the issue to Karl-Heinz.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 22, 2014, 06:40:16 am
Maybe you have mentioned it several times... What is the method used for measuring inductance, capacitance? I am thinking an LC meter spin-off.

I'd go for the frequency based solution (LC oscillator) for higher accuracy and a larger measurement range. The Transistor Tester uses:
- U_c(t) = U_in * (1 - e^(-t/RC)) for capacitance
- i_L(t) = I_0 * (1 - e^(-t R / L)) for inductance (limited by the max. test current supported)
Title: Re: $20 LCR ESR Transistor checker project
Post by: kubi48 on July 22, 2014, 07:48:56 am
Hi guys, decided to show it working. Have to say, it works like charm, considering that it's built in such a rude way  ;D I discovered interesting little glitch - you test diode, it displays it OK (symbol), but when you reverse connection, symbol gets messed up ??? Does someone have similar problem? I think it's connected either with LCD or EEPROM

I could not verify this effect with my hardware and the developer version 1.11k :-[. Probably you can send the .hex and .eep together with your Makefile to my Email address.
You can find the Email address at the front page of my PDF documentation. Usually the actual versions for the ATmega328 don't use the EEPROM for text and
fix table data because the USE_EEPROM option is deactivated in the Makefile. Only calibration data are hold in the EEPROM. So you need only load the .hex data to the flash memory. The EEPROM is initilized automatically, if no valid data are found.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 22, 2014, 09:41:23 am
Hi guys, decided to show it working. Have to say, it works like charm, considering that it's built in such a rude way  ;D I discovered interesting little glitch - you test diode, it displays it OK (symbol), but when you reverse connection, symbol gets messed up ??? Does someone have similar problem? I think it's connected either with LCD or EEPROM

I could not verify this effect with my hardware and the developer version 1.11k :-[. Probably you can send the .hex and .eep together with your Makefile to my Email address.
You can find the Email address at the front page of my PDF documentation. Usually the actual versions for the ATmega328 don't use the EEPROM for text and
fix table data because the USE_EEPROM option is deactivated in the Makefile. Only calibration data are hold in the EEPROM. So you need only load the .hex data to the flash memory. The EEPROM is initilized automatically, if no valid data are found.

The odd thing is that it's only the diode symbol, and only the one that's supposed to point to the right. Also, I noticed that the glitch isn't always the same. Below is a photo of the tester with a dual diode device. I will email you a copy of the hex file. I use "make upload" and avrdude to upload the firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on July 22, 2014, 09:44:08 am
Try other firmware version. I think I saw this problem a few months ago. But after replacing firmware it never appeared again.
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 23, 2014, 11:35:51 am
Karl-Heinz has fixed the diode symbol issue and the fix is out in the repository. Thanks!

http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/)
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on July 23, 2014, 06:58:51 pm
What version contains LCR and ESR? m or k?

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 23, 2014, 11:23:43 pm
What version contains LCR and ESR? m or k?

Both, also in-circuit ESR.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on July 26, 2014, 07:52:48 am
I finished my component tester. The varnish is not perfect, but I got it for free.
Finished Universal component avr tester with ATmega328 (http://www.youtube.com/watch?v=4lVIVKr36iM#)
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on July 26, 2014, 06:40:10 pm
You really went ape shit on this one. Thanks for sharing.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 26, 2014, 10:27:06 pm
I finished my component tester. The varnish is not perfect, but I got it for free.

Nice rugged DIY design!  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on July 27, 2014, 05:03:37 am
I like the credit for the firmware -- nice touch!
Title: Re: $20 LCR ESR Transistor checker project
Post by: SeanB on July 27, 2014, 05:16:35 am
I like that repurposed case you used. Even nicer is the 2 power input sockets so almost any power brick can be used as well irrespective of centre pin thickness.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on July 27, 2014, 06:39:13 am
In fact the metal case was never used before. A friend gave me that. It can be 10 years old or so.
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on July 27, 2014, 06:44:51 pm
Will you post a bit more detail of your work aka pics of its guts?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Hydrawerk on July 28, 2014, 04:51:35 am
Some photos are included in the beginning of this video.
Universal component avr tester with ATmega328 (http://www.youtube.com/watch?v=NCSb3vqkbqA#)
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on July 28, 2014, 09:18:15 am
Some photos are included in the beginning of this video.

A very nice job. I'm jealous and will have to seriously consider an ATmega328 version for myself.

One very minor little error I noticed: Correct spelling is "clamp the 3 leads together". Something for Karl to fix in the next build, I suspect.
Title: Re: $20 LCR ESR Transistor checker project
Post by: nickds1 on July 29, 2014, 02:28:43 am
On the subject of typographical corrections, in the UK (and I suspect most native-English countries), we use "V" rather then "U" for voltage...
Title: Re: $20 LCR ESR Transistor checker project
Post by: retrolefty on July 29, 2014, 05:12:14 am
On the subject of typographical corrections, in the UK (and I suspect most native-English countries), we use "V" rather then "U" for voltage...

Good thing we use the same number symbols.  ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 29, 2014, 06:34:02 am
I could not verify this effect with my hardware and the developer version 1.11k :-[. Probably you can send the .hex and .eep together with your Makefile to my Email address.
You can find the Email address at the front page of my PDF documentation. Usually the actual versions for the ATmega328 don't use the EEPROM for text and
fix table data because the USE_EEPROM option is deactivated in the Makefile. Only calibration data are hold in the EEPROM. So you need only load the .hex data to the flash memory. The EEPROM is initilized automatically, if no valid data are found.
Hi, I used already compiled version (so I don't have a Makefile), link you can find in post #573. I used avrdude GUI (BitBurner  :-+) to write the software, manually - flash then EEPROM then fuses  8)
Title: Re: $20 LCR ESR Transistor checker project
Post by: torch on July 29, 2014, 06:38:53 am
On the subject of typographical corrections, in the UK (and I suspect most native-English countries), we use "V" rather then "U" for voltage...

I had to watch that a second time. For anyone else who missed that the first time: He uses V for the results, but Uf for "forward voltage".
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on July 29, 2014, 01:44:22 pm
Hi Madires,
I had a problem after updated the firmware with the most recent mega328_st7565 version in the trunk with my eBay ESR meter shown in #510.
While the meter still can be turned on/off after flashing the firmware, there is no display. I set the LCD_ST7565_RESISTOR_RATIO = 7,  and then i was able to see some faint display. I am wondering what parameters in the makefile should be set to make it working properly?

I used WinAVR-20100110 with an USBasp from ebay to updated to the newest firmware.

Thanks and appreciate your help!
I am new here and also a newbie for electronics. I got mine today from ebay. It is with Atmel Mega328p AU chip, it impressed me with all SMD components and even with a Tantalum capacitor!
However, they failed to acknowledge Karl-Heinz K"ubbeler, madires and everyone else who contributed to the firmware design.

The seller claimed it is 2014 "latest" version. However when started the program, it showed:
"Transistor Tester V2.1". Wondering what exactly firmware it is running.

ALso, I am planning to upgrade the firmware anyway to the newest version using the ISP port, I am actually wondering what version of LCD should I use? Thanks!
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 30, 2014, 03:42:07 am
Karl-Heinz has fixed the diode symbol issue and the fix is out in the repository. Thanks!

http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/)
Hi guys, I have a problem here with fixed software. I push a button it says battery voltage and vcc, seems allright, but it lasts for around 5 sec. then it displays "Cell!" (see attachments), tried a new battery, no luck  :-BROKE
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on July 30, 2014, 03:54:02 am
it lasts for around 5 sec. then it displays "Cell!" (see attachments), tried a new battery, no luck  :-BROKE

You probably need to adjust the Makefile parameters for the voltage divider built onto your board (+protection diode loss).
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 30, 2014, 04:18:59 am
You probably need to adjust the Makefile parameters for the voltage divider built onto your board (+protection diode loss).
Sadly enough, I probably can't do that because I'm pretty  |O on this kind of stuff. I have 7805 on board (you want to say in Makefile a LDO regulator is specified?) + I did not installed protection diode  :-[
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 30, 2014, 04:40:46 am
You probably need to adjust the Makefile parameters for the voltage divider built onto your board (+protection diode loss).
You meant this section "# Voltage divider for battery voltage measurement  10k / 3.3k = 133/33
#CFLAGS += -DBAT_NUMERATOR=133
#CFLAGS += -DBAT_DENOMINATOR=33
# Voltage divider for the external zener voltage measurement 180k / 20k = 10/1
#CFLAGS += -DEXT_NUMERATOR=10
#CFLAGS += -DEXT_DENOMINATOR=1" ?
Also I found this interesting section: "# The CAP_EMPTY_LEVEL  defines the empty voltage level for capacitors in mV.
# Choose a higher value, if your Tester reports "Cell!" by unloading capacitors.
CFLAGS += -DCAP_EMPTY_LEVEL=4"
More of it, I don't have needed software to compile it
P.S. Sorry for flooding, if you can I'll prefer to PM you
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 30, 2014, 04:51:52 am
While the meter still can be turned on/off after flashing the firmware, there is no display. I set the LCD_ST7565_RESISTOR_RATIO = 7,  and then i was able to see some faint display. I am wondering what parameters in the makefile should be set to make it working properly?

That value selects the resistor divider of the module's internal voltage regulator. For most ST7565 displays 4 or 7 work fine but you could also try other values from 0 up to 7.
Title: Re: $20 LCR ESR Transistor checker project
Post by: KK on July 30, 2014, 06:52:54 am
Bought this one with zener measurement. They say it has a atmega168 but the one sent to me had an atmega328.

I soldered pins into the icsp pads and updated the software to the latest trunk. The protection fuses weren't set but it came with an older version, I believe it was 1.08k of firmware.

The LCD is smaller than expected, and the backlight and readability are just ok.

But, it does work well.

http://www.ebay.com/itm/Transistor-Tester-Capacitor-ESR-Inductance-Resistor-Meter-Mosfet-Diode-Battery-/121346078072 (http://www.ebay.com/itm/Transistor-Tester-Capacitor-ESR-Inductance-Resistor-Meter-Mosfet-Diode-Battery-/121346078072)
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on July 30, 2014, 09:43:44 am
I tried all values and seems only LCD_ST7565_RESISTOR_RATIO = 7 gave me a faint display, with other values, there is no display at all.
Is there anything else i should look at?
Thanks.

While the meter still can be turned on/off after flashing the firmware, there is no display. I set the LCD_ST7565_RESISTOR_RATIO = 7,  and then i was able to see some faint display. I am wondering what parameters in the makefile should be set to make it working properly?

That value selects the resistor divider of the module's internal voltage regulator. For most ST7565 displays 4 or 7 work fine but you could also try other values from 0 up to 7.
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 31, 2014, 03:14:16 am
Got it working again! Reason is jumper on the solder side, when I pushed IC in place pin poked jumper through, effectively connecting pin 25 of AtMega328 to anode of backlight LED  :o  Big thanks to Karl Heinz, no more issues with diode symbol & double diodes  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 31, 2014, 04:13:52 am
I tried all values and seems only LCD_ST7565_RESISTOR_RATIO = 7 gave me a faint display, with other values, there is no display at all.
Is there anything else i should look at?

I think the next step is to identify the LCD module and to get the datasheet. Maybe it needs some additional initialization.
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 31, 2014, 07:18:24 am
Excuse me please, but can someone show me where I can find full schematic (with ability to measure frequency). All I know - the pin 6 of the AtMega is the input  :-[
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on July 31, 2014, 10:03:26 am
Excuse me please, but can someone show me where I can find full schematic (with ability to measure frequency). All I know - the pin 6 of the AtMega is the input  :-[

http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/)

click on link to download the "GNU tarball". You'll need the GNU tools tar and gzip or something like 7-Zip to extract the files. Look at the file ttester_eng110k.pdf.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on July 31, 2014, 11:49:04 am
Has anyone done a video showing the self-test/calibration process for my MK-168 Transistor Tester M168_V2.20. I see lots of videos about these things but I'm not sure if the Calibration process has been demoed.
section 3.3 Selftest and Calibration in the .PDF explains it a bit - http://www.avrtester.tode.cz/upload/ttester_en.pdf (http://www.avrtester.tode.cz/upload/ttester_en.pdf) - but I'd like to see how it works by watching someone doing it.

The documentation mentions disconnecting the leads for a certain test and only connecting a cap after a certain prompt so I don't want to do it wrong.
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on July 31, 2014, 03:07:49 pm
http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/)
click on link to download the "GNU tarball". You'll need the GNU tools tar and gzip or something like 7-Zip to extract the files. Look at the file ttester_eng110k.pdf.
Thanks a lot, I didn't knew that this directory is existing  ::)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on July 31, 2014, 11:14:19 pm
The documentation mentions disconnecting the leads for a certain test and only connecting a cap after a certain prompt so I don't want to do it wrong.

It's pretty simple. Short circuit the three probe pins/leads and start the calibration (actually adjustment). After a few tests you'll be asked to remove the short circuit and some more tests are run. Then the tester displays the cap symbol and you connect a cap (film cap 220nF - 1µF recommended) to probes #1 and #3. That's the procedure for the k-firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: firewalker on July 31, 2014, 11:26:06 pm
The main difference between the k and m firmwares is that the k-firmware includes support for ESR measurement and the m-firmware has a simple menu system and a PWM tool.

Is the above statement still valid?

Alexander.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 01, 2014, 12:04:41 am
The documentation mentions disconnecting the leads for a certain test and only connecting a cap after a certain prompt so I don't want to do it wrong.

It's pretty simple. Short circuit the three probe pins/leads and start the calibration (actually adjustment). After a few tests you'll be asked to remove the short circuit and some more tests are run. Then the tester displays the cap symbol and you connect a cap (film cap 220nF - 1µF recommended) to probes #1 and #3. That's the procedure for the k-firmware.

OK, seems simple enough.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 01, 2014, 12:51:18 am
The documentation mentions disconnecting the leads for a certain test and only connecting a cap after a certain prompt so I don't want to do it wrong.

It's pretty simple. Short circuit the three probe pins/leads and start the calibration (actually adjustment). After a few tests you'll be asked to remove the short circuit and some more tests are run. Then the tester displays the cap symbol and you connect a cap (film cap 220nF - 1µF recommended) to probes #1 and #3. That's the procedure for the k-firmware.

I'm not sure which firmware I have but the Version 1.11k May 27, 2014 .PDF I found says...

"A capacitor with any capacity between 100nF and 20F connected to pin 1 and pin 3 is required
for the last task of calibration. To indicate that, a capacitor symbol is shown between the pin number
1 and 3, followed by the text " >100nF". You should connect the capacitor not before this text is
shown. With this capacitor the o set voltage of the analog comparator will be compensated for better
measurement of capacity values. Additionally the gain for ADC measurements using the internal
reference voltage will be adjusted too with the same capacitor for better resistor measurement results
with the AUTOSCALE ADC option. If the menu option is selected for the tester and the selftest is
not started as menu function, the calibration with the external capacitor is only done for the rst
time calibration. The calibration with the external capacitor can be repeated with a selftest call as
menu selection.
The zero o set for the ESR measurement will be preset with the option ESR ZERO in the
Make le. With every self test the ESR zero values for all three pin combinations are determined.
The solution for the ESR measurement is also used to get the values of resistors below 10 with a resolution of 0:01."
Title: Re: $20 LCR ESR Transistor checker project
Post by: robimarko on August 01, 2014, 05:33:27 am
Hi,
finally spare amtega 328 arrived,where can I find compiled 1.11k firmware ready for flashing?
Tried to find it myself but no luck so far
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 01, 2014, 06:57:20 am
The main difference between the k and m firmwares is that the k-firmware includes support for ESR measurement and the m-firmware has a simple menu system and a PWM tool.

Is the above statement still valid?

No, the current major differences are a frequency counter and support of ST7565 based LCD modules (k-firmware). The next m-firmware version will include the frequency counter too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 01, 2014, 07:01:07 am
Hi,
finally spare amtega 328 arrived,where can I find compiled 1.11k firmware ready for flashing?
Tried to find it myself but no luck so far

Please see http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) or one of the other mega328 subdirectories for different hardware setups.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 01, 2014, 07:06:56 am
I'm not sure which firmware I have but the Version 1.11k May 27, 2014 .PDF I found says...

That's the long explanation ;) I'm pretty sure that your clone runs the k-firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 01, 2014, 08:31:45 am
I'm not sure which firmware I have but the Version 1.11k May 27, 2014 .PDF I found says...

That's the long explanation ;) I'm pretty sure that your clone runs the k-firmware.

I just connected all three mini-grabbers together and it's firmware 1.10K

I went through all 7 tests and used one of those 200nF X2 caps. I tested some caps I already tried out this morning and the ESR readings are much lower now.
One that was 0.36ohm this morning is now 0.05ohm.

Next I ran the seven tests again but this time I used a 10uF Nichicon electrolytic.
I think I'm maybe getting more realistic numbers now. A 224uf 100V cap that measured Vloss= 1.3%, ESR=0.7ohm this morning now measures Vloss= 1.4%, ESR=0.4ohm
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 02, 2014, 03:15:37 am
I just got one of these testers and tried to update the firmware using these files:
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/)

I successfully flashed the .hex and .eep files using avrdude, but the tester doesn't working any more.  The LCD just displays solid blocks for the first row.  Did I use the right files for this tester?:

http://www.ebay.com/itm/2014-Atmega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-/181442767546 (http://www.ebay.com/itm/2014-Atmega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-MOS-PNP-NPN-/181442767546)
(note: the IC is actually a TQFP 328P)

I wasn't too worried as I had made a backup of the original firmware before updating, but when I tried to restore these avrdude wouldn't recognise the format.  I'm attaching the files and would appreciate any advice on what is wrong with them.


Also, I tried to use the makefile through WinAVR but I kept getting an error.  Does the makefile work on the .hex/.eep files linked above or do I need to download some other files?

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 02, 2014, 07:12:45 am
I went through all 7 tests and used one of those 200nF X2 caps. I tested some caps I already tried out this morning and the ESR readings are much lower now.
One that was 0.36ohm this morning is now 0.05ohm.

Next I ran the seven tests again but this time I used a 10uF Nichicon electrolytic.
I think I'm maybe getting more realistic numbers now. A 224uf 100V cap that measured Vloss= 1.3%, ESR=0.7ohm this morning now measures Vloss= 1.4%, ESR=0.4ohm

Have you noticed that the difference is about 0.3 Ohms for both measurements? The self-adjustment has measured a resistance of 0.15 Ohms for the probe leads (2 in series = 0.3 Ohms) and the tester uses that offset to auto-zero any resistance measurement. The cap is used to determine the offset of the internal bandgap voltage reference and the offset of the analog comparator. It's purpose is to hold a voltage for a few ms. The type isn't important, as long as the cap is able to keep the voltage constant (low internal losses).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 02, 2014, 07:30:59 am
I successfully flashed the .hex and .eep files using avrdude, but the tester doesn't working any more.  The LCD just displays solid blocks for the first row.  Did I use the right files for this tester?:

Yes, those are the correct files! The most common issue is a wrong setting for the ISP programmer. In a few cases additional bypass caps were needed (please see ttester.pdf in the documentation sub-folder).

Quote
Also, I tried to use the makefile through WinAVR but I kept getting an error.  Does the makefile work on the .hex/.eep files linked above or do I need to download some other files?

You need the complete source code in the "trunk" directory.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 02, 2014, 09:06:37 am
I haven't done much programming of micros using the command line so I always end up using the same settings that worked in the past.  Is there anything wrong with this command?

Code: [Select]
avrdude -c arduino -C ../etc/avrdude.conf -p atmega328p -P com6 -b19200 -U eeprom:w:TransistorTester.eep -U flash:w:TransistorTester.hex

Both the flash and eeprom say verified after they're written.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 02, 2014, 09:17:53 pm
... In a few cases additional bypass caps were needed (please see ttester.pdf in the documentation sub-folder).

I added the bypass caps, similar to the picture in this post: http://www.eevblog.com/forum/testgear/14399/msg221946/#msg221946 (http://www.eevblog.com/forum/testgear/14399/msg221946/#msg221946)

Still no luck - when I press the button the LCD light up with solid blocks on the first row.  I does go off when I let go of the button now, but that has to do with the firmware or fuses as I noticed the change before adding the caps.

I managed to load the backup flash and eeprom data by specifying it as raw data, but I'm not surprised it didn't work as I downloaded it as hex.  I still can't understand why it won't upload it in the same format as I read it from the chip.

I tried compiling both the k- and m-firmware.  They don't give me any errors writing to the micro but it still won't work.

Anyone knows what else it could be?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 03, 2014, 12:44:17 am
I haven't done much programming of micros using the command line so I always end up using the same settings that worked in the past.  Is there anything wrong with this command?

Code: [Select]
avrdude -c arduino -C ../etc/avrdude.conf -p atmega328p -P com6 -b19200 -U eeprom:w:TransistorTester.eep -U flash:w:TransistorTester.hex

Both the flash and eeprom say verified after they're written.

Seems to be fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 03, 2014, 01:00:34 am
Still no luck - when I press the button the LCD light up with solid blocks on the first row.  I does go off when I let go of the button now, but that has to do with the firmware or fuses as I noticed the change before adding the caps.

Anyone knows what else it could be?

Another idea would be to change the BOD setting in the e-fuse. The default setting of the Makefile is 0xfc (4.3V). Please set the e-fuse to 0xfd (2.7V) and try again. Especially with some hardware options the supply voltage might not rise fast enough for the MCU and the MCU will detect that as a brown-out and resets (and keeps doing that as long as you press the push button).
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 03, 2014, 06:07:52 am
Another idea would be to change the BOD setting in the e-fuse. The default setting of the Makefile is 0xfc (4.3V). Please set the e-fuse to 0xfd (2.7V) and try again. Especially with some hardware options the supply voltage might not rise fast enough for the MCU and the MCU will detect that as a brown-out and resets (and keeps doing that as long as you press the push button).

Just tried that, still doesn't work.  0xfd gets changed to 0x5 which I believe is the same setting (for that matter 0xfc gets changed to 0x4).  The e-fuse setting it came with was 0x7 (BOD disabled?), and that doesn't work either.

The only difference I've noticed is that with BOD settings below 4.3V, the LCD and LED stay on after I let go of the button.  They do time out eventually (~70s).

Edit:  Just noticed the LED only turns on after I let go of the button and turns off again if I hold the button down.  Not sure if it's supposed to do this.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 03, 2014, 06:51:07 am
The only difference I've noticed is that with BOD settings below 4.3V, the LCD and LED stay on after I let go of the button.  They do time out eventually (~70s).

At least some progress ;) That means that the MCU is running and after a few test cycles the tester powers off as intended. The next step is to check the LCD module. Contrast? Which pin of the LCD is connected to which pin of the ATmega? If you got another LCD module, you could try that one.

Quote
Edit:  Just noticed the LED only turns on after I let go of the button and turns off again if I hold the button down.  Not sure if it's supposed to do this.

That's ok, it's designed that way.
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 03, 2014, 08:40:08 am
... Which pin of the LCD is connected to which pin of the ATmega?

I think I've spotted the problem - most of the pins don't match the schematic:

RS - PD7
E - PD5
D4 - PD4
D5 - PD3
D6 - PD2
D7 - PD1

The do seem to match the pinout for the stripboard version though!  I'll try to load that version in the morning (I've learned not to work on electronics when I'm tired!).  Loading the wrong version shouldn't have caused any damage right?
Title: Re: $20 LCR ESR Transistor checker project
Post by: nessatse on August 03, 2014, 08:08:30 pm
Just completed my own version (http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg470219/#msg470219 (http://www.eevblog.com/forum/testgear/)), and I must congratulate Karl-Heinz and Markus on this magnificent project.  An example of true engineering.  :-+

I have however picked up a small problem with the 1.13m version.  It seems that resistors in the range between approximately 1.5k and 3k are incorrectly identified as double diodes.  I verified this using a 4k7 trimpot and stepping through its range.  It does not matter which pins I use, at about 1.5k it starts identifying as a double diode almost all the way to about 3k.  I loaded the 'k' version of the software and it works perfectly throughout the range.

I cannot discount the possibility that there is something wrong with my hardware, but I think the likelihood is low, since it works perfectly for every other component I have thrown at it so far.

I have started looking at the source to try and figure out where it is going wrong, but that may take a while.  Any suggestions?


Edit: Added image.  Two diodes with cathodes going to the same pin?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 03, 2014, 09:12:43 pm
The do seem to match the pinout for the stripboard version though!  I'll try to load that version in the morning (I've learned not to work on electronics when I'm tired!).  Loading the wrong version shouldn't have caused any damage right?

The ATmega should have survived the different pinout. The only issue would be the test button, if the ATmega's pin is set to high output and is short circuited by the BJT when the test button is pressed. But the ATmega is able to take some pain ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: ion on August 03, 2014, 10:31:23 pm
The do seem to match the pinout for the stripboard version though!  I'll try to load that version in the morning (I've learned not to work on electronics when I'm tired!).  Loading the wrong version shouldn't have caused any damage right?

The ATmega should have survived the different pinout. The only issue would be the test button, if the ATmega's pin is set to high output and is short circuited by the BJT when the test button is pressed. But the ATmega is able to take some pain ;)

Well, it did survive.  Just loaded the stripboard version of the latest firmware and it's working great (http://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif)

Thanks for all the help.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 04, 2014, 12:22:10 am
I have however picked up a small problem with the 1.13m version.  It seems that resistors in the range between approximately 1.5k and 3k are incorrectly identified as double diodes.  I verified this using a 4k7 trimpot and stepping through its range.  It does not matter which pins I use, at about 1.5k it starts identifying as a double diode almost all the way to about 3k.  I loaded the 'k' version of the software and it works perfectly throughout the range.

I can reproduce the problem and will look into it. Thanks for reporting!

Quote
I have started looking at the source to try and figure out where it is going wrong, but that may take a while.  Any suggestions?

It's the diode detection.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on August 04, 2014, 07:32:30 am
Hi Madires,
Display problem solved.
I don't know what changes was brought to the most recent mega328_st7565 trunk version, i modified the makefile:
CD_ST7565_RESISTOR_RATIO = 5
CFLAGS += -DFONT_6X8
I don't know why CFLAGS += -DFONT_8X16 always gave me an: "avrdude: ERROR: address 0x8010 out of range at line 2049 of ./TransistorTester.hex" message

and the display is working properly now. However, there's a minor problem with the display, the left side character is only partially displayed, is there anyway to fix it?

Thanks for your help!


I tried all values and seems only LCD_ST7565_RESISTOR_RATIO = 7 gave me a faint display, with other values, there is no display at all.
Is there anything else i should look at?
Thanks.

While the meter still can be turned on/off after flashing the firmware, there is no display. I set the LCD_ST7565_RESISTOR_RATIO = 7,  and then i was able to see some faint display. I am wondering what parameters in the makefile should be set to make it working properly?

That value selects the resistor divider of the module's internal voltage regulator. For most ST7565 displays 4 or 7 work fine but you could also try other values from 0 up to 7.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 04, 2014, 08:24:51 am
I have however picked up a small problem with the 1.13m version.  It seems that resistors in the range between approximately 1.5k and 3k are incorrectly identified as double diodes.  I verified this using a 4k7 trimpot and stepping through its range.  It does not matter which pins I use, at about 1.5k it starts identifying as a double diode almost all the way to about 3k.  I loaded the 'k' version of the software and it works perfectly throughout the range.

Please edit semi.c and change in function CheckDiode()

Code: [Select]
    U1_Zero /= 50;            /* 2% */
    U1_Rh += U1_Zero;         /* 102% */

into

Code: [Select]
    U1_Zero /= 10;            /* 10% */
    U1_Rh += U1_Zero;         /* 110% */

5% (/= 20) might be also sufficient.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 04, 2014, 08:52:39 am
I don't know why CFLAGS += -DFONT_8X16 always gave me an: "avrdude: ERROR: address 0x8010 out of range at line 2049 of ./TransistorTester.hex" message

The ATmega328 has only 32k flash ;)

Quote
and the display is working properly now. However, there's a minor problem with the display, the left side character is only partially displayed, is there anyway to fix it?

That's strange! Seems to be related to the font based positioning. Could you please delete all object files and recompile the firmware. Maybe something got stuck when you tried the 8x16 font.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on August 04, 2014, 09:55:56 am
No luck recompiled the files   |O
 
I don't know why CFLAGS += -DFONT_8X16 always gave me an: "avrdude: ERROR: address 0x8010 out of range at line 2049 of ./TransistorTester.hex" message

The ATmega328 has only 32k flash ;)

Quote
and the display is working properly now. However, there's a minor problem with the display, the left side character is only partially displayed, is there anyway to fix it?

That's strange! Seems to be related to the font based positioning. Could you please delete all object files and recompile the firmware. Maybe something got stuck when you tried the 8x16 font.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hdlg_zhangyu on August 04, 2014, 10:18:15 am
modified the lcd-routines.c
set the cursor at each line start with (x,1), and the problem is fixed.
Will this change have any negative effects? e.g. alter the display at end of each line?



No luck recompiled the files   |O
 
I don't know why CFLAGS += -DFONT_8X16 always gave me an: "avrdude: ERROR: address 0x8010 out of range at line 2049 of ./TransistorTester.hex" message

The ATmega328 has only 32k flash ;)

Quote
and the display is working properly now. However, there's a minor problem with the display, the left side character is only partially displayed, is there anyway to fix it?

That's strange! Seems to be related to the font based positioning. Could you please delete all object files and recompile the firmware. Maybe something got stuck when you tried the 8x16 font.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 05, 2014, 02:17:03 am
modified the lcd-routines.c
set the cursor at each line start with (x,1), and the problem is fixed.
Will this change have any negative effects? e.g. alter the display at end of each line?

Great! I don't think it will cause any new problems.
Title: Re: $20 LCR ESR Transistor checker project
Post by: nessatse on August 05, 2014, 03:39:48 am


Quote from: nessatse on Yesterday at 11:08:30 (http://www.eevblog.com/forum/index.php?topic=14399.msg490259#msg490259)
I have however picked up a small problem with the 1.13m version.  It seems that resistors in the range between approximately 1.5k and 3k are incorrectly identified as double diodes.  I verified this using a 4k7 trimpot and stepping through its range.  It does not matter which pins I use, at about 1.5k it starts identifying as a double diode almost all the way to about 3k.  I loaded the 'k' version of the software and it works perfectly throughout the range.



Please edit semi.c and change in function CheckDiode()

Code: [Select] (http://www.eevblog.com/forum/javascript:void(0);)    U1_Zero /= 50;            /* 2% */
    U1_Rh += U1_Zero;         /* 102% */

into

Code: [Select] (http://www.eevblog.com/forum/javascript:void(0);)    U1_Zero /= 10;            /* 10% */
    U1_Rh += U1_Zero;         /* 110% */

5% (/= 20) might be also sufficient.


Thanks! It works with both 5% and 10%!  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 05, 2014, 06:34:54 am
I just tried to measure two 10000uF 50V Nichicon caps with my MK-168 tester (firmware 1.10K) and they both keep measure no bigger than 5986uF

Is this the limit of these testers?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 05, 2014, 06:45:01 am
I just tried to measure two 10000uF 50V Nichicon caps with my MK-168 tester (firmware 1.10K) and they both keep measure no bigger than 5986uF

Is this the limit of these testers?

The theoretical limit is 100mF and I've tested up to 22mF successfully with several testers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 05, 2014, 07:12:46 am
I just tried to measure two 10000uF 50V Nichicon caps with my MK-168 tester (firmware 1.10K) and they both keep measure no bigger than 5986uF

Is this the limit of these testers?

The theoretical limit is 100mF and I've tested up to 22mF successfully with several testers.

Yup. I think these two caps might be quite bad. They both measure way too low uF-wise and around 4ohm or more ESR.

I just tried the other capacitor test (C+ESR@TP1:3) you get when you hold down the button and I like it better for testing a bunch of caps because it just keeps testing endlessly. The big caps give me about the same numbers with that test too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 05, 2014, 11:03:36 pm
I just tried to measure two 10000uF 50V Nichicon caps with my MK-168 tester (firmware 1.10K) and they both keep measure no bigger than 5986uF

Is this the limit of these testers?

The theoretical limit is 100mF and I've tested up to 22mF successfully with several testers.

I just did a test and you're right, it can easily do 10mF because I connected two 4700uF caps in parallel and it reads C=10.7mF and ESR=0.04ohm

This give me more confidence that those 10000uF caps are bad. Maybe I can resurrect the Onkyo receiver I removed them from :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on August 15, 2014, 12:21:46 pm
I have a question about the "Button" connection for the Zener expansion option. Should the gate of T4 be tied directly to PD7, or is there supposed to be a button switch between the two, or something else?

Attached is the schematic from the ttester.pdf manual.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 16, 2014, 05:24:53 am
I have a question about the "Button" connection for the Zener expansion option. Should the gate of T4 be tied directly to PD7, or is there supposed to be a button switch between the two, or something else?

Yes, please connect the gate of T4 directly to PD7.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on August 18, 2014, 12:36:55 pm
knowing what you all know about the testers available on e----, if you had your choice on which one to buy and it can be updated and will work, which one would you buy?
I would appreciate a particular one and not just anyone will work. I don't want to guess and get the wrong one or one that does not work or can't be updated.

Thanks
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 18, 2014, 10:56:16 pm
knowing what you all know about the testers available on e----, if you had your choice on which one to buy and it can be updated and will work, which one would you buy?
I would appreciate a particular one and not just anyone will work. I don't want to guess and get the wrong one or one that does not work or can't be updated.

Basically any clone with an ATmega328 and a standard 2x16 LCD display will work fine. If you're looking for a particular recommendation please read a few posts back and you'll find several links, pictures and comments on specific models.

PS: Firmware 1.14m was released a few days ago with some minor improvements, a fix for the resistor issue (1k5-3k) and the frequency counter option. There's also an adapter PCB (DIY-style, Eagle files) for the rotary encoder and frequeny counter input stage in the hardware sub-directory in the SVN.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JoeO on August 19, 2014, 12:58:49 pm
The only thing I would recommend is that you purchase one with a DIP socketed 328.  That way you can buy a spare 328, program it up to the latest level and swap it in to test it.  If the new 328 does not work, just revert back to the old 328.
Title: Re: $20 LCR ESR Transistor checker project
Post by: AlessandroAU on August 22, 2014, 05:14:47 am
Does anyone have any experience with these variations that are popping up on ebay?

I don't really have any reference standard to compare it to but it seems to measure and identify any passive I can throw at it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrewwong2000 on August 22, 2014, 07:40:29 am
Hey Alessandro

That's the "LCR T3" design.

Any chance you can read the flash and EEPROM and email to me ?

These ones use an older version of the firmware but I'm trying to figure out that display so it can be upgradeable.

That one you have has a 6pin ISP pin pad but it's reversed on the component side :)



Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: v0yAgEr on August 24, 2014, 09:56:04 am
Hi everyone,
Can someone please confirm that mk-168 unit is indeed m328 and supports firmware upgrades? I really want to buy one, but I want to make sure I got that covered first.
Thanks!

Chinese MK-168 Electronic Component Tester review/demo [1/2] (http://www.youtube.com/watch?v=b3dPBnYixs4#ws)
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on August 24, 2014, 11:00:27 am
Hi everyone,
Can someone please confirm that mk-168 unit is indeed m328 and supports firmware upgrades? I really want to buy one, but I want to make sure I got that covered first.
Thanks!

Chinese MK-168 Electronic Component Tester review/demo [1/2] (http://www.youtube.com/watch?v=b3dPBnYixs4#ws)

The video doesn't show what's under the LCD, so you can't tell from the video alone. The board also seems to be single sided--most singled sided versions of the board don't seem to have a programming header. Since it has "168" in the name, my guess is it uses the ATmega168 rather than Atmega328. I would look for another variant.
Title: Re: $20 LCR ESR Transistor checker project
Post by: v0yAgEr on August 24, 2014, 04:45:39 pm
Hi everyone,
Can someone please confirm that mk-168 unit is indeed m328 and supports firmware upgrades? I really want to buy one, but I want to make sure I got that covered first.
Thanks!

Chinese MK-168 Electronic Component Tester review/demo [1/2] (http://www.youtube.com/watch?v=b3dPBnYixs4#ws)

The video doesn't show what's under the LCD, so you can't tell from the video alone. The board also seems to be single sided--most singled sided versions of the board don't seem to have a programming header. Since it has "168" in the name, my guess is it uses the ATmega168 rather than Atmega328. I would look for another variant.

Thanks for the reply!
If not that unit, then Im looking for something like this:
Flashable m328, and would really like to have a model with probes for in-circuit testings. Any recommendations?
Title: Re: $20 LCR ESR Transistor checker project
Post by: omgfire on August 24, 2014, 05:06:45 pm
Hi everyone,
Can someone please confirm that mk-168 unit is indeed m328 and supports firmware upgrades? I really want to buy one, but I want to make sure I got that covered first.
Thanks!
http://www.eevblog.com/forum/beginners/what's-your-favorite-little-inexpensive-esr-etc-tester/msg470124/#msg470124 (http://www.eevblog.com/forum/beginners/what's-your-favorite-little-inexpensive-esr-etc-tester/msg470124/#msg470124)
Title: Re: $20 LCR ESR Transistor checker project
Post by: v0yAgEr on August 24, 2014, 08:22:24 pm
Great! Ordering now...
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on August 26, 2014, 12:50:38 pm
I bought a couple of these testers... the fish8840 version with the nice graphics LCD.  Yeah,  probably not as upgrade friendly as the character LCD units,  but I'm a sucker for pretty pictures (but it doesn't draw pictures for SCR's and TRIACs).  They work very well.  So far it has properly identified everything I've thrown at it (except some big SCRs and TRIACs that it can't drive the gate hard enough.  Component values measurements are in the .2% accuracy range.  All in all,  the best 20 bucks you can spend...

Both units had a problem where they would not turn on with a fresh battery installed...  the screen would just flash once and then go off.  A few of simple fixes for this...  use a used battery,  a low ohm resistor in series with the battery (2 ohms worked for me), or replace the 78L05 regulator with an LM2936 ultra low power LDO regulator... same pinouts as the 78L05 and it also drops a few mA from the operating current...  that was my ultimate solution to the problem.

The other problem is the battery voltage divider is connected permanently across the battery.  The OFF current is 180 uA...  will drain the battery in a couple of months.  I moved the input of the voltage divider resistors from the battery connection to the input of the voltage regulator (i.e. after the power-switch transistor).  This reduces the OFF current to well below 1 micro-amp.

One really useful addition to the firmware would be the ability to measure the Rds ON resistance of FETs...
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on August 28, 2014, 04:49:59 pm
Great! Ordering now...

I just ordered one of these myself from Amazon after seeing the teardown. Which firmware should I use on this? There seems to be so many versions of these and the firmware, I’m a little confused. Edit: After looking around, since this uses an AT328P and standard 20x2 LCD, I guess the m328 build is what I’m after?

Another question, after watching the YouTube video you linked, this seems to show the battery voltage on startup. Is there a regulator onboard? I’d like to power this from a small LiPo battery with a tiny LiPo -> 5V boost converter. Is that battery test feature part of the “official” firmware?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Wh1sper on August 28, 2014, 10:51:15 pm
Does anyone have any experience with these variations that are popping up on ebay?

I don't really have any reference standard to compare it to but it seems to measure and identify any passive I can throw at it.

I do own this one without case.
It measure quite well not so exact like my other selfmade one. I guess the resictors are not so high quality ones.

I wished there were some more information about the LCD Hardware .. Controller.. etc.
Downside is the software isn't open any more :-(
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on August 28, 2014, 11:19:32 pm
Downside is the software isn't open any more :-(
You mean Transistor Tester is not an open source anymore?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on August 29, 2014, 12:24:56 am
Downside is the software isn't open any more :-(
You mean Transistor Tester is not an open source anymore?

No worries! The official Transistor Tester firmware (k and m version) is open source!!! Unfortunately some clone vendors modify the source and claim ownership while violating the copyright of the original authors. It doesn't make much sense to try stopping them, because that would require a lot of money for lawyers. Therefore my advice is to buy only hardware compatible clones, since those can be upgraded to the current firmware version. If you buy a clone with a modified hardware/firmware, you might never get any update from the vendor. And a self-made tester is best one anyway ;)

PS: The next m-firmware version will have a squarewave signal generator (up to 2MHz for 8MHz MCU clock) operated by the rotary encoder supporting dynamic turning velocity.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Wh1sper on August 29, 2014, 03:23:29 am
Downside is the software isn't open any more :-(
You mean Transistor Tester is not an open source anymore?
No no, only the Chinese modifier don't publish their modifications.
That's what a meant.
What a dissipation of human brain power.
Imagine those Chinese guys (or girls?) would contribute their improvements and / or modifications.......
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on August 30, 2014, 05:20:03 pm
So, my MK-168 unit came in today. The build quality is pretty nice overall; it uses an AT328P in a socket, with no footprint for an ICSP header. Looking at the board it seems to have been designed late last year. Some markings on the board: M168_V2.20, M8/168/328_9V_V2.20, 2013.10.16, EZM Electronics Studio.

The one real problem I found was C3 and R11 only being soldered on one side. (Looks like the missing solder was on the ground side, which even took my iron a few seconds to heat up, so I suspect whatever worker made this board didn’t have their iron hot enough.)

Another thing I noticed was the lack of a Zener diode, which I thought was required for a voltage reference? The other thing of note is SMD capacitors C1 (missing), C6, C7 and C8 on the back. There’s plenty of board space on the front, so I thought that was a weird decision. The last oddity is what appears to be a bodge resistor connecting pin 2 of the ATmega to VCC.

The package came with what you’d expect, the unit in a case, three test leads and a ZIF/SMD adapter. In addition to the standards the seller also threw in a power cable for rigging up your own external supply and an extra power connector (not sure what’s up with that).

Here’s full resolution versions of the attached pictures if you want to examine the front or back of the board in detail: http://img.timb.us/index.php?f=TrannyTaster (http://img.timb.us/index.php?f=TrannyTaster)
Title: Re: $20 LCR ESR Transistor checker project
Post by: dentaku on August 30, 2014, 09:59:40 pm
So, my MK-168 unit came in today. The build quality is pretty nice overall; it uses an AT328P in a socket, with no footprint for an ICSP header. Looking at the board it seems to have been designed late last year. Some markings on the board: M168_V2.20, M8/168/328_9V_V2.20, 2013.10.16, EZM Electronics Studio.

The one real problem I found was C3 and R11 only being soldered on one side. (Looks like the missing solder was on the ground side, which even took my iron a few seconds to heat up, so I suspect whatever worker made this board didn’t have their iron hot enough.)

Another thing I noticed was the lack of a Zener diode, which I thought was required for a voltage reference? The other thing of note is SMD capacitors C1 (missing), C6, C7 and C8 on the back. There’s plenty of board space on the front, so I thought that was a weird decision. The last oddity is what appears to be a bodge resistor connecting pin 2 of the ATmega to VCC.

The package came with what you’d expect, the unit in a case, three test leads and a ZIF/SMD adapter. In addition to the standards the seller also threw in a power cable for rigging up your own external supply and an extra power connector (not sure what’s up with that).


I have exactly the same one with all the same markings. I just opened it up to make sure it's soldered right and I don't have the bodge resistor on pin 2, C1 is unpopulated and C3 and R11 are soldered just fine and I see no zener.

I'm guessing the jack came with the power cord so they just included it. I've never used it with a battery before so it's nice to be able to plug it in.

I like the ZIF adapter for testing large amounts of capacitors because it's much quicker and less fiddly than mini grabbers.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on August 30, 2014, 10:52:36 pm
After doing some reading, it seems C1 being unpopulated is correct. Yeah, I love the ZIF socket. Between that and the SMD pads (I sorted through a drawer of random FETs tonight, so fast) I think using the leads will be rare.

The ZIF doesn't scream quality to me, but it's by no means bad either. (I've seen much worse on much more expensive gear.) I figure I can always buy a new socket if it breaks.


Sent from my iPhone
Title: Re: $20 LCR ESR Transistor checker project
Post by: RLSprouse on August 31, 2014, 03:39:20 am

Another thing I noticed was the lack of a Zener diode, which I thought was required for a voltage reference? The other thing of note is SMD capacitors C1 (missing), C6, C7 and C8 on the back. There’s plenty of board space on the front, so I thought that was a weird decision. The last oddity is what appears to be a bodge resistor connecting pin 2 of the ATmega to VCC.


I assume the "bodge resistor" you refer to is the little surface mount package.  I believe that is on pin 27, not pin 2, if I remember how to count pins on a DIP.
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrewwong2000 on August 31, 2014, 08:51:52 pm
Thought Id share..

I built 3 of Frenchie's Transistor Tester boards to practice my first go at 0603 SMD soldering, plus have a bit of fun.

Great little board that fits neatly behind a LCD display

Thanks to Markus, Karl Heinz and Frenchie !(http://tapatalk.imageshack.com/v2/14/08/31/33be50b04de769e1631c1ccc65bc9362.jpg)


Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 01, 2014, 04:29:33 am
Why is there an Atmega88 and not a 328 on Frenchies board? And which resistors should be 0.1% ones? Why use 0.1% ones in the first place when the software calibrates itself and there's a voltage reference on board?
Title: Re: $20 LCR ESR Transistor checker project
Post by: radioFlash on September 01, 2014, 06:01:21 am
R1-R6 on the schematic should be .1%. They are the 680 and 470k resistors.


Sent from my iPhone using Tapatalk
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 01, 2014, 06:13:51 am
But why, if the tester calibrates against a precision voltage reference?
Title: Re: $20 LCR ESR Transistor checker project
Post by: MrJohnnny on September 01, 2014, 06:56:52 am
No worries! The official Transistor Tester firmware (k and m version) is open source!!! Unfortunately some clone vendors modify the source and claim ownership while violating the copyright of the original authors. It doesn't make much sense to try stopping them, because that would require a lot of money for lawyers. Therefore my advice is to buy only hardware compatible clones, since those can be upgraded to the current firmware version. If you buy a clone with a modified hardware/firmware, you might never get any update from the vendor. And a self-made tester is best one anyway ;)

PS: The next m-firmware version will have a squarewave signal generator (up to 2MHz for 8MHz MCU clock) operated by the rotary encoder supporting dynamic turning velocity.
OK, thanks for response. In order to thank authors I decided to build it myself, even when it will came out not as good as bought one, I feel proud using it  8) (and I did, I use it now very often), without giving money to Chinese for a thing, that they didn't invented   >:( I'll like to try m-version, however, with such stuff I'm dealing with having an inductance meter is very helpful. Seems like I need to think about making another one for m-version exlusively, hmmm...
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 01, 2014, 08:01:09 am

But why, if the tester calibrates against a precision voltage reference?

It doesn't calibrate against a precision reference as I understand it. It simply uses the ADC's reference input which is either VCC or 1.5V.

The 2.5V precision reference is optional. From my understanding of the PDF linked on page 1, it's only used for measuring the battery voltage accurately.

Either way, the more accurate the resistor, the more accurate the calibration.


(Incidentally, the Chinese MK-168 I got uses 0.1% resistors, which shocked the shit out of me. Well, unless they're just painting a purple band on some cheapies!)


Sent from my iPhone
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 01, 2014, 08:04:51 am


Another thing I noticed was the lack of a Zener diode, which I thought was required for a voltage reference? The other thing of note is SMD capacitors C1 (missing), C6, C7 and C8 on the back. There’s plenty of board space on the front, so I thought that was a weird decision. The last oddity is what appears to be a bodge resistor connecting pin 2 of the ATmega to VCC.


I assume the "bodge resistor" you refer to is the little surface mount package.  I believe that is on pin 27, not pin 2, if I remember how to count pins on a DIP.

Spot on. I was looking at the board with the chip out of the socket when I wrote that.

So this is where the precision reference should go. Lucky I've got about 6 REF5025's in a sealed bag around here somewhere. Time to customize!


Sent from my iPhone
Title: Re: $20 LCR ESR Transistor checker project
Post by: markce on September 01, 2014, 08:19:44 am
I've got a MK168 as well. It was amazingly accurate in both R end C measuments, but no zener in place.
Looked it up, and it's only used as added function in calibration mode. The voltage regulator used on this
board nice and much better than an ordinary 78l05. Given the construction and the accuracy, I'll not mod it
anywhere soon. Pleased with it as it is.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 01, 2014, 11:53:27 am
Yeah, I was just going through the README in Markus’ firmware and it says this:

Quote
The external 2.5V voltage reference should be only enabled if it's at least
10 times more precise than the voltage regulator. Otherwise it would make
the results worse. If you're using a MCP1702 with a typical tolerance of
0.4% as voltage regulator you really don't need a 2.5V voltage reference.

The regulator used in the MK-168 is the AMS1117-5V (http://www.advanced-monolithic.com/pdf/ds1117.pdf), which isn’t quite as good as the MCP1702 and others, but like you said, more than acceptable I think. I might still install the reference for the hell of it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 02, 2014, 03:34:02 am
It doesn't calibrate against a precision reference as I understand it. It simply uses the ADC's reference input which is either VCC or 1.5V.

The 2.5V precision reference is optional. From my understanding of the PDF linked on page 1, it's only used for measuring the battery voltage accurately.

The optional external 2.5V reference is used to determine the offset of Vcc (5V). That offset has an impact on the self-adjustment of the internal bandgap reference and all measurements.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 02, 2014, 06:49:04 pm
Right. I was just stating that the optional 2.5V Ref wasn't used as the ADC's reference input or anything.

(And of course by battery accuracy I meant VCC.)


Sent from my iPhone
Title: Re: $20 LCR ESR Transistor checker project
Post by: Scaramanga on September 02, 2014, 08:10:32 pm
Hello everyone!

I just bought one of these , version 2.4 2013/07/01

i just wanted to ask:

I saw people in the first pages installing decoupling caps near by the chip, while others don't. What are the benefits of it?
Sorry if i sound silly but i'm not familiar with µC world
Thanks in advance

Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 03, 2014, 03:19:53 am
I saw people in the first pages installing decoupling caps near by the chip, while others don't. What are the benefits of it?
Sorry if i sound silly but i'm not familiar with µC world

The decoupling caps keep the voltage of the power supply stable if the load, i.e. the current draw of the MCU, changes. You can read more about that at https://en.wikipedia.org/wiki/Decoupling_capacitor for example.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Scaramanga on September 04, 2014, 04:29:01 am
ok thanks for your response  :-+
I'm new at electronics, after thinking about it i don't think i will put more money on this gadget. I'd better spend my time & money into learning more about electronics  rather than trying to modify this low-cost gadget :P
i just removed the zener as suggested & i'll leave it as it is. I'll calibrate it if ever i find a low-tolerance film capacitor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: moemoe on September 04, 2014, 05:00:54 am
If anyone here should be interested, I'm running a centralized order on my variant of the board. Price per board is 3.50€, shipping (worldwide) 3,10€ or 5,05€ for >2 boards.

It's designed to fit into the http://www.reichelt.de/SP-6000-SW/3/index.html?&ACTION=3&LA=446&ARTICLE=33838&artnr=SP+6000+SW (http://www.reichelt.de/SP-6000-SW/3/index.html?&ACTION=3&LA=446&ARTICLE=33838&artnr=SP+6000+SW) Strapubox 6000, equipped with a http://www.mouser.de/ProductDetail/ELECTRONIC-ASSEMBLY/EA-DOGM162W-A/?qs=sGAEpiMZZMv8dIMJ2cKI/LMZh%252b6hoZs2 (http://www.mouser.de/ProductDetail/ELECTRONIC-ASSEMBLY/EA-DOGM162W-A/?qs=sGAEpiMZZMv8dIMJ2cKI/LMZh%252b6hoZs2) EA DOMG Display (mostly because it's much smaller than a normal 2x16 Display).

All Data is available on https://github.com/maugsburger/avr-component-tester (https://github.com/maugsburger/avr-component-tester) and some images on the first posts here: http://www.mikrocontroller.net/topic/343407 (http://www.mikrocontroller.net/topic/343407) and http://www.mikrocontroller.net/topic/314097 (http://www.mikrocontroller.net/topic/314097)

In opposite to most china versions it can test zener diodes up to 30V, too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 04, 2014, 11:27:23 pm
i just removed the zener as suggested & i'll leave it as it is. I'll calibrate it if ever i find a low-tolerance film capacitor.

It doesn't have to be a low-tolerance film capacitor, any film cap >100nF is fine. I use an 1µF MKT for example.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 05, 2014, 12:27:50 am
So I built my reference last night! The REF5025 requires a low ESR cap between 1 and 10uF on the output for stability. To keep things nice and compact I dug through my box of donor boards and found a nice 10uF Tantalum SMD on an old motherboard. With a bit of work I was able to solder it to the output lead and ground ring of the SOIC breakout board I was using. I also added a 10uF ceramic across the input and output leads for good measure.

Here it is with a 555 for comparison:
(http://tapatalk.imageshack.com/v2/14/09/04/924a01c916fdf07a9fc0d13d7ee1f890.jpg)

Plus the obligatory close up shot:
(http://tapatalk.imageshack.com/v2/14/09/04/7802d79f2972751ea6fa4ddb1d32a2be.jpg)

I'll mount it to the top of the MK-168 board with some double sided tape and tap GND and VCC directly from two components in front of it, then run a small lead directly to the reference input.

I know this is a bit overkill, but I've got a ton of these REF5025's leftover from a client project awhile back. (These are the high grade versions, too!)


Sent from my Smartphone
Title: Re: $20 LCR ESR Transistor checker project
Post by: Scaramanga on September 05, 2014, 03:46:56 am

It doesn't have to be a low-tolerance film capacitor, any film cap >100nF is fine. I use an 1µF MKT for example.

ah i see

so the quality factor is about the reactance/esr at given frequency

is a mkp capacitor from fluo lamp ok ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 05, 2014, 10:35:22 am
Is there an easy way to disable continuous mode with Markus’ firmware? I find it’s a bit wasteful for me, since I’m not testing a string of components at a time. Also, I’ve got to say that this firmware feels a lot slower than the version in the trunk directory. Maybe it’s something in my settings?

Edit: I set #define CYCLE_MAX to 1 in config.h, but it still seems to go more than once sometimes (I know if I hit the button after a measurement it’ll go again, but I don’t touch anything and it’ll go again once and awhile it seems; mainly after I’ve just measured a component).

On another note, I got my reference installed. Works great!

(http://img.timb.us/MK-168_REF5025_1.jpg)

(http://img.timb.us/MK-168_REF5025_2.jpg)

That big capacitor that’s folded over next to the reference board is a 10uF I added to help filter the output of the voltage regulator. Turns out they have *no* capacitor directly on the output! (I’ve got it soldered to the pin of a resistor which is the first thing the regulator’s output connects to [first solder connection coming from the regulator’s tab in the second picture].) This should help keep the regulator’s output a lot more stable.
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on September 05, 2014, 11:03:26 am
That big capacitor that’s folded over next to the reference board is a 10uF I added to help filter the output of the voltage regulator. Turns out they have *no* capacitor directly on the output!

If you are using an LDO  or low quiescent current regulator,  they pretty much require caps on the input and output or else they turn into dandy oscillators.  Also the output cap cannot have too high OR LOW of an ESR value.   And there may be limits on the capacitance that they require (again can't be too high or low).  Always check the data sheet when using an LDO or low quiescent current type of regulator.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 05, 2014, 11:35:00 am
That big capacitor that’s folded over next to the reference board is a 10uF I added to help filter the output of the voltage regulator. Turns out they have *no* capacitor directly on the output!

If you are using an LDO  or low quiescent current regulator,  they pretty much require caps on the input and output or else they turn into dandy oscillators.  Also the output cap cannot have too high OR LOW of an ESR value.   And there may be limits on the capacitance that they require (again can't be too high or low).  Always check the data sheet when using an LDO or low quiescent current type of regulator.

Yup, exactly. That’s why I was surprised there wasn’t one. They were filtering the input from the DC Jack, the input to the LDO and the pins between VCC and GND, but that’s about it. I checked the datasheet for the AMS1117 and it requires one, hence adding the 1uF electrolyte.

TI actually makes some “cap free” LDOs, and a bunch that are stable with ceramic outputs, which can save on the expense of buying tantalums.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 05, 2014, 03:06:58 pm
Hmmm, my tester seems to be off by an order of a magnitude on capacitors with the 1.14m software. 100uF caps are reading 10uF! Any idea what could be causing this?

It helps if you set the fuse bits for an 8MHz Crystal instead of the internal 1MHz resonator! (http://img.timb.us/emoticon/ughh.gif)

So, my actual and real problem is that I can’t get it to measure inductors at all. :(
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 06, 2014, 08:18:47 pm
is a mkp capacitor from fluo lamp ok ?

Haven't tried one yet, but it should be fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 06, 2014, 08:24:21 pm
Is there an easy way to disable continuous mode with Markus’ firmware? I find it’s a bit wasteful for me, since I’m not testing a string of components at a time.

Please press the push button when powering on a little bit longer (>0.3s). For powering off it's the same procedure.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 06, 2014, 08:32:39 pm
It helps if you set the fuse bits for an 8MHz Crystal instead of the internal 1MHz resonator!

So, my actual and real problem is that I can’t get it to measure inductors at all. :(

The internal RC oscillator is 8MHz too, but the clock prescaler is set to 8 by default. Are you using an ATmega 168 or 328?
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 07, 2014, 04:12:13 am

It helps if you set the fuse bits for an 8MHz Crystal instead of the internal 1MHz resonator!

So, my actual and real problem is that I can’t get it to measure inductors at all. :(

The internal RC oscillator is 8MHz too, but the clock prescaler is set to 8 by default. Are you using an ATmega 168 or 328?

Right, but I had the fuse bits on the Mega328 chip set to the defaults, which is internal @ 1MHz. So I had uploaded the hex and eep with make upload, but forgot to do a make fuses afterwards.

That's why the thing was running so dog slow and not measuring things correctly.

So I did get it to measure a large (500uH) inductor last night. But it's seeing my smaller (4.7uH) ones as capacitors. Is there some sort of limit on the size of inductors it can measure?


Sent from my Smartphone
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 07, 2014, 06:33:34 am
So I did get it to measure a large (500uH) inductor last night. But it's seeing my smaller (4.7uH) ones as capacitors. Is there some sort of limit on the size of inductors it can measure?

Yes, the lower limit is about 100µH.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 07, 2014, 06:37:19 am

So I did get it to measure a large (500uH) inductor last night. But it's seeing my smaller (4.7uH) ones as capacitors. Is there some sort of limit on the size of inductors it can measure?

Yes, the lower limit is about 100µH.

Thanks! Can you go into more detail on why it's limited to that? I'd be interested in helping to add support for lower and more precise inductor measurements.


Sent from my Smartphone
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on September 07, 2014, 08:37:28 am
My Chinese version with the graphics display does a fairly decent job on inductors starting out around 20 uH
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 07, 2014, 10:20:52 am
Hi:
Could I get anyones thoughts on this meter?
Has anyone purchased this one and been able to update it and how did you do it or is this one not to be purchased. I was looking at the ones with the larger display, but I believe it was mentioned that you cannot update it with the files mentioned here.
http://www.ebay.com/itm/291041497713?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/291041497713?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)   Thanks for any help.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: MickM on September 07, 2014, 03:07:44 pm
Hi amtpdb;
   I bought one of as a gift.
The AVR is locked by the fusebits.
AVRDUDE will read it ok, but the file is length 0.

Nevertheless it is a good clone, and does ESR

Mick M
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 07, 2014, 03:15:12 pm
Hi amtpdb;
   I bought one of as a gift.
The AVR is locked by the fusebits.
AVRDUDE will read it ok, but the file is length 0.

Nevertheless it is a good clone, and does ESR

Mick M

Thanks Mick
Is there anything I should know before I buy it to change? Can you put a header on it easy enough to change the program and did you change the program? Did you change the atmega out? Is there one that you would consider other then this one now that you purchased it? I am a newbe, do you need to change out the resistor or anything?
I appreciate your getting back so quickly.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 07, 2014, 08:30:12 pm
Thanks! Can you go into more detail on why it's limited to that? I'd be interested in helping to add support for lower and more precise inductor measurements.

Based on the hardware design the only feasable method for measuring inductance is to track the current change of the inductor when a current is applied. To measure low inductances a high test current is required but the MCU's limit is 20mA. In "safe" mode (about 7mA, limited by the 680 Ohms probe resistor) the tester can measure down to about 100µH. But there's also an "unsafe" mode which overloads the MCU's I/O pin for a short period of time and allows a measurement down to 10µH. The unsafe mode is entered if the tester doesn't detect an inductor in the safe mode and the resistance of the DUT is less than 40 Ohms. So far we haven't seen any issues with that, but the measurements in the low inductance range are not very accurate.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JoeO on September 07, 2014, 10:21:48 pm
amtpdb;

I bought 2 of these also.  Under the LCD is a DIP socketed 328P.  There is no connector to program it on the board.  You would have to remove it to modify the program.

This is the BEST design because you can buy a second 328P and program it.  Test it on the board  and if it does not work, reinsert the original 328P
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 07, 2014, 10:32:44 pm
Some changes for v1.15m to improve the inductance measurement a little bit more. In inductance.c in function MeasureInductance() in the "process counters" section please change:

Code: [Select]
Offset = -4;                /* subtract processing overhead */
to
Code: [Select]
Offset = -3;                /* subtract processing overhead */

Remove or comment out the following line:
Code: [Select]
    Counter += (CPU_FREQ / 2000000);         /* add half of cycles for rounding */

And change
Code: [Select]
  if (Counter <= 500) Flag = 2;         /* signal "inductance too low" */
to
Code: [Select]
  if (Counter <= 100) Flag = 2;         /* signal "inductance too low" */

The changes above will be included in the next release.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 07, 2014, 10:52:05 pm

Some changes for v1.15m to improve the inductance measurement a little bit more. In inductance.c in function MeasureInductance() in the "process counters" section please change:

Code: [Select]
Offset = -4;                /* subtract processing overhead */
to
Code: [Select]
Offset = -3;                /* subtract processing overhead */

Remove or comment out the following line:
Code: [Select]
    Counter += (CPU_FREQ / 2000000);         /* add half of cycles for rounding */

And change
Code: [Select]
  if (Counter <= 500) Flag = 2;         /* signal "inductance too low" */
to
Code: [Select]
  if (Counter <= 100) Flag = 2;         /* signal "inductance too low" */

The changes above will be included in the next release.

Thanks, I'll give this a go today and report back!

So, one issue I've run into with reprogramming my Mega328 chips after flashing this firmware is the fact I can't reprogram them! After some head scratching I realized (after some Googling) that it's because the fuse bits are set for an 8MHz crystal and the MCU won't start at all (even for programming) without one in place.

This is about the dumbest fycking thing I've ever seen! Why the hell wouldn't Atmel have designed the chip to default to a "safe mode" using the internal oscillator during programming?

Since I don't have any 8MHz crystals laying around I'm just using male to female jumper straps to go from the xtal ports on the socket to the chip's pins during programming.

(For the record, I'm an MSP430 and ARM programmer mainly, so the concept of setting these type of things via fuses is very alien to me. It seems especially dumb to have clock settings done this way since you can basically lock yourself out of the chip unless you happen to have a HV programmer laying around. I much prefer setting the clock speed via software registers, which has the added advantage of dynamic frequency selections to save power!)


Sent from my Smartphone
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 07, 2014, 11:31:37 pm
Since I don't have any 8MHz crystals laying around I'm just using male to female jumper straps to go from the xtal ports on the socket to the chip's pins during programming.

Some ISP programmers provide a clock signal for those cases.
Title: Re: $20 LCR ESR Transistor checker project
Post by: timb on September 07, 2014, 11:34:05 pm
Yeah, I've only got a Bus Pirate and hand-built ArduinoISP Shield (with 16MHz crystal installed). I guess I could generate an 8MHz clock with my function generator? Still a pain the ass though.


Sent from my Smartphone
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 14, 2014, 01:41:05 am
Am I mistaking or is the MCP1700 rated at 6V input, but connected to the 9V battery?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 14, 2014, 10:30:17 pm
Am I mistaking or is the MCP1700 rated at 6V input, but connected to the 9V battery?

The recommended LDO voltage regulator is a MCP1702 which supports an input voltage up to 13.2V.
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 16, 2014, 08:37:06 pm
Thank you, I thought so. I have another set of question, if you're a not fed up already:

As I was skimming through the svn repository, I was a bit con-f-used by the following passage in the Makefile:

Quote
# The WITH_UART option enables the software UART  (TTL level output at Pin PC3, 26).
# If the option is deselected, PC3 can be used as external voltage input with a
# 10:1 resistor divider.
#CFLAGS += -DWITH_UART

# With option TQFP_ADC6 or/and TQFP_ADC7 you can use the additional pins of the TQFP or
# the QFN package for external analog input. You should install a 10:1 voltage dividers
# on the selected pin(s).
# If both pins are defined, both voltages are measured with the voltage measure function.
# But for zener diode measurement the ADC6 pin is used, if both pins are defined.
CFLAGS += -DTQFP_ADC6
CFLAGS += -DTQFP_ADC7

# For ATmega8/168/328 processor the option WITH_VEXT can only be set, if the PC3 pin
# is not used for serial output (WITH_UART option).
# For ATmega644/1284 processor the UART has a separate pin.  Therefore the external input
# at pin ADC3 can be enabled separate by setting the WITH_UART option.
CFLAGS += -DWITH_VEXT

So you can measure Zeners or a voltage on ADC6 and additionally another external voltage on ADC7. Do you have to set -DWITH_VEXT for that? I assume not as VEXT says it "can only be set if the PC3 pin is not used." It would be annoying having to abstain from UART to measure voltages.

PC3 gives UART output. If you don't set  -DWITH_UART, you can set -DWITH_VEXT and get an extra voltage input, right? Does that make three  extra voltage inputs, when  -DTQFP_ADC6 and  -DTQFP_ADC7, -DWITH_VEXT are set and -DWITH_UART is not?

Why is there even -DWITH_VEXT and -DWITH_UART? Wouldn't one of them suffice if you can't use VEXT with UART enabled? If you disable UART and VEXT, does PC3 do nothing?

Finally, why is the voltage reference only used for measuring the battery voltage? I'd imagine the whole thing would be more accurate if you calibrated against the optional external voltage reference.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 18, 2014, 03:42:44 am
So you can measure Zeners or a voltage on ADC6 and additionally another external voltage on ADC7. Do you have to set -DWITH_VEXT for that? I assume not as VEXT says it "can only be set if the PC3 pin is not used." It would be annoying having to abstain from UART to measure voltages.

Yes, you should set WITH_VEXT if you're using ADC6 and/or ADC7 together with WITH_UART. Just the combination of WITH_VEXT and WITH_UART without TQFP_ADC6 or TQFP_ADC7 set doesn't work. TQFP_ADC6 and TQFP_ADC7 are switches for re-defining the pins used for the external voltage measurement.

Quote
PC3 gives UART output. If you don't set  -DWITH_UART, you can set -DWITH_VEXT and get an extra voltage input, right? Does that make three  extra voltage inputs, when  -DTQFP_ADC6 and  -DTQFP_ADC7, -DWITH_VEXT are set and -DWITH_UART is not?

No, either you got PC3 or ADC6/ADC7.

Quote
Why is there even -DWITH_VEXT and -DWITH_UART? Wouldn't one of them suffice if you can't use VEXT with UART enabled? If you disable UART and VEXT, does PC3 do nothing?

Both are options. If you don't set any of them, both are disabled and PC3 is unused.

Quote
Finally, why is the voltage reference only used for measuring the battery voltage? I'd imagine the whole thing would be more accurate if you calibrated against the optional external voltage reference.

No, the external voltage reference is used to determine the offset of Vcc (5V). That offset is used for all measurements.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on September 18, 2014, 10:15:47 am
Why is there even -DWITH_VEXT and -DWITH_UART? Wouldn't one of them suffice if you can't use VEXT with UART enabled? If you disable UART and VEXT, does PC3 do nothing?

I'm afraid I might be at least partially responsible for that by virtue of suggesting that when I have no use for serial output, I would rather not waste the microcontroller's resources on generating extra data and noise on the PC3 pin. Prior to this option being available in the make file, I had to go into the source and comment out the #define lines for VEXT because unsetting WITH_UART would result in the device trying to measure voltage every time I accidentally held the test button in a little longer. Very annoying when you have no zener extension.
Title: Re: $20 LCR ESR Transistor checker project
Post by: AlessandroAU on September 22, 2014, 05:34:21 am
Hey Alessandro

That's the "LCR T3" design.

Any chance you can read the flash and EEPROM and email to me ?

These ones use an older version of the firmware but I'm trying to figure out that display so it can be upgradeable.

That one you have has a 6pin ISP pin pad but it's reversed on the component side :)



Sent from my iPhone using Tapatalk

I tired to read the chip using my tl866. I can get the chip ID fine, but when I try to read from it just appears blank. Some form of copy protection?
Title: Re: $20 LCR ESR Transistor checker project
Post by: pol098 on September 23, 2014, 06:53:54 am
In case anyone is interested in the graphics versions: they are described and sold within China on a Web site in Chinese only:
http://fish8840.taobao.com/ (http://fish8840.taobao.com/) I prefer to open it in Google Chrome, which offers to translate it automatically, or on a right-click. I don't know whether the many sources of these devices buy from fish8840 (in which case they'd be all be of equal quality) or make their own copies.

Presumably fish8840 is the originator of the Chinese hardware versions (although they themselves may be imitated!), and weiweitm adapted the software. The reason for production of a graphics version given is that a text-only display in Latin characters is difficult for Chinese people, which makes sense; there are traditional and simplified Chinese, and English-language versions. There are two versions, an older one with a green display, and a later one with a slightly larger blue display; both are sold, with the blue one a little more expensive. The pictures don't show a crystal visible on the board; it could be there but hidden. As far as I can tell the later board was released in March 2014; the only software appears to be weiweitm's version 2.1 (with no mention of providing source code). I don't know if there is any provision at all for software updates (socketed chip, header, any intention to produce downloadable updates). There is a picture of an elegantly cased version, branded Yiwanjia, but no indication (such as price) that it exists.

Foreigner Markus F is acknowledged. The translation is difficult to understand in detail; I think Translate's "shelves without shell" are uncased boards!

Web pages of the two hardware versions (Chinese):
Larger screen, blue, backlit 25/3/2014, software shows as 2.1 on pictures:
http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.16.IhvBUf&id=36323329572 (http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.16.IhvBUf&id=36323329572)
Smaller green graphics screen version:
http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.19.IhvBUf&id=37659767669 (http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.19.IhvBUf&id=37659767669)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 23, 2014, 09:51:50 pm
Foreigner Markus F is acknowledged. The translation is difficult to understand in detail; I think Translate's "shelves without

Evidently the firmware is based on Karl-Heinz' source code. So much for proper credits. >:(
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on September 24, 2014, 06:15:35 pm
I suspect that they are simply ignorant of the fact that someone other than "Foreigner Markus F." needs to be credited. Maybe if you or K.-H. contacted them and told them what needs to be done, this could be easily corrected. Just a thought.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 25, 2014, 01:27:52 am
I bought one of the blue testers http://www.ebay.co.uk/itm/New-Transistor-NPN-PNP-MOSFET-Diode-Tester-Capacitor-ESR-Resistor-Meters-UK-Ship-/271551234681 (http://www.ebay.co.uk/itm/New-Transistor-NPN-PNP-MOSFET-Diode-Tester-Capacitor-ESR-Resistor-Meters-UK-Ship-/271551234681) the other day and its a great piece of kit for the price but I had to carry out some modifications to get it to behave.

1.
It would sometimes display "VCC=x.xV" underneath the battery voltage and according to ttester_eng110k.pdf this should only happen if there is a voltage reference installed, which this one does not have. The voltage it would show changed every measurement along with the test result, a 2.2k pull-up resistor from VCC to pin 27 fixed this.

Quote
Missing precision voltage reference Usually the software should detect the missing voltage reference with the unconnected pin PC4. In this case no VCC=x.xV message should appear in row 2 of the LCD on power on. If this message appear without the reference, you should connect a 2:2k resistor to the PC4 input and VCC.
It was almost like it was switching between the internal reference and what ever pin 27 was floating at, for example the battery voltage would randomly go from reading 8.5v to 7v and then 9v. The test results were only accurate when the uC detected no reference was installed.

2.
The AMS1117-5.0 voltage regulator was missing bypass capacitors on its output so I paralleled up a 100nF and 22uF as per the datasheets recommendation. Looking on my oscilloscope I noticed a slightly cleaner output and a much better transient response. Not sure if this makes any difference to measurements though.

3.
C1 was missing on the AREF pin so I installed a 1nF as per the manuals suggestion (I have firmware version 1.11k).

4.
On mine the wire to the green front cover connector had a dry solder joint so I redid it, on closer inspection each connector has a small hole on the end for the wires to thread through but for some reason they were ignored during manufacturing.

5
The track routing for AGND at pin 22 took a separate and very scenic route around the PCB before it met up with pin 7 and the uC's decoupling capacitor, effectively isolating it from said capacitor. So I soldered a 100nF ceramic directly across pins 20 and 22 in an attempt to reduce the effects of the long trace on the analog sections supply rails.

This image shows the additional capacitor and the long route from AGND to the regulator and factory decoupling cap on pin 8 GND.

(https://i.imgur.com/Jg24EXq.jpg)

Too anyone who has one of these, have you noticed that the ESR measurements tend to change depending on which way around you have the probes? Seems to be related to the temperature of the capacitor and my fingers heating it slightly, the warmer the cap the lower the ESR reading.
Title: Re: $20 LCR ESR Transistor checker project
Post by: pol098 on September 25, 2014, 04:39:06 am
... Maybe if you or K.-H. contacted them and told them what needs to be done, this could be easily corrected ...

It might even be interesting for somebody (I think it would have to be someone who knows Chinese) to contact the people making the Chinese graphics devices and software, welcome their activity, and suggest that they could add their contributions to the shared software, that they would get useful feedback from here (e.g. Alex1's recent detailed contribution should be helpful to them), and that a system could be set up to distribute updates? They could even sell pre-programmed ATmega328s to those who don't want to do it themselves.

I hope this doesn't step on the toes of the legitimate developers here, not my intention, just a "more the merrier" idea.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 25, 2014, 04:46:43 am
I just purchased the one listed below. Does anyone have any suggestions on what should be done to make it more accurate or better? By this I see that some of you replaced resistors and caps, reprogrammed the chip (where is the latest update?).
Thanks for any help. I have been following this thread for some time but still  don't know too much about electronics but want to learn! That is one reason I purchase this item.
Thanks

http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 26, 2014, 03:29:06 am
It might even be interesting for somebody (I think it would have to be someone who knows Chinese) to contact the people making the Chinese graphics devices and software, welcome their activity, and suggest that they could add their contributions to the shared software, that they would get useful feedback from here (e.g. Alex1's recent detailed contribution should be helpful to them), and that a system could be set up to distribute updates? They could even sell pre-programmed ATmega328s to those who don't want to do it themselves.

That's a good idea! I always encourage contributors and users to send bug reports, add-ons, modifications and so on.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 26, 2014, 09:44:11 am
@madires Looking on a scope during a capacitance test it seems that this tester will apply a high reverse voltage directly across the capacitor during one half of the cycle, which for an electrolytic is bad.

Should it be placing such a reverse voltage across the capacitor?

Below shows my scope which is DC coupled to the output of the tester with a 1200uF capacitor connected across it. Shouldn't this cause the capacitor to break down during one half of the test cycle?

(https://i.imgur.com/utMEORC.png)

2v/div 500ms/div
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on September 26, 2014, 11:06:30 am
It's not long enough or high enough of a voltage/current to do any damage.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 26, 2014, 11:13:25 am
It's not long enough or high enough of a voltage/current to do any damage.

But wouldn't it be safer to limit the test voltage to something under a capacitors reverse breakdown voltage of 1.5v?
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on September 26, 2014, 11:19:57 am
It's not long enough or high enough of a voltage/current to do any damage.

But wouldn't it be safer to limit the test voltage to something under a capacitors reverse breakdown voltage of 1.5v?

You can't do that with a processor/circuit that is using 5V digital I/O pins.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 26, 2014, 12:21:17 pm
You can't do that with a processor/circuit that is using 5V digital I/O pins.

What about if one lead of the tester was designated as positive so that it could always be connected to the positive side of the capacitor by the user, or would the way the test works break that?
Title: Re: $20 LCR ESR Transistor checker project
Post by: SeanB on September 26, 2014, 02:40:20 pm
LONG term reverse voltage will damage an electrolytic, but a short term ( less than 1 second) non repetitive pulse will have no effect. Repetitive reverse pulses will destroy it, asa they average out as a long term reverse voltage. Remember a non polarised electrolytic is subjected to a reverse voltage on each foil, and they last decades in service.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 26, 2014, 05:18:38 pm
Fair enough then if its just long term reverse polarity that does damage.

I was just having a :scared: moment thinking that I might have just done something stupid on an appliance I am repairing for a friend.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 26, 2014, 09:14:33 pm
@madires Looking on a scope during a capacitance test it seems that this tester will apply a high reverse voltage directly across the capacitor during one half of the cycle, which for an electrolytic is bad.

Should it be placing such a reverse voltage across the capacitor?

Below shows my scope which is DC coupled to the output of the tester with a 1200uF capacitor connected across it. Shouldn't this cause the capacitor to break down during one half of the test cycle?

What you saw seems to be some test for another component. During the capacitance measurement the polarity of an electrolytic cap might be reversed, but the current is limited to 7mA and 10ms pulses for the first phase (high capacitance) and is limited to 10µA for the second phase (low capacitance). During the first phase a voltage of more than 300mV across the cap will end the test. The test for small capacitance limits the voltage to the internal bandgap reference (ATmega168/328: 1.1V). The ESR measurement creates pulsed forward and reverse voltages for a few µs each, also limited to 7mA. If you're concerned about running the other tests you could run the tester's in-circuit ESR measurement via the menu.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 27, 2014, 08:48:04 pm
What you saw seems to be some test for another component.

During the first phase a voltage of more than 300mV across the cap will end the test.

So it shouldn't be doing the test displayed on the waveform? The atmega328 has version 1.11k according to the end of the self calibration routine.

If you're concerned about running the other tests you could run the tester's in-circuit ESR measurement via the menu.

What is the procedure to access this menu?

Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 27, 2014, 10:26:06 pm
The atmega328 has version 1.11k according to the end of the self calibration routine.
Latest version should be 1.10k.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 27, 2014, 10:39:05 pm
The atmega328 has version 1.11k according to the end of the self calibration routine.
Latest version should be 1.10k.

It definitely says 1.11k.

What you saw seems to be some test for another component. During the capacitance measurement the polarity of an electrolytic cap might be reversed, but the current is limited to 7mA and 10ms pulses.

During the first phase a voltage of more than 300mV across the cap will end the test. The test for small capacitance limits the voltage to the internal bandgap reference (ATmega168/328: 1.1V).
[/b]

This definitely doesn't look right then.

Some waveforms taken during a capacitor test, all 2 volts and 1 second a division.
From top to bottom is 10uF, 1500uF (reads 1222uF) and then 2200uF.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 28, 2014, 12:00:16 am
So it shouldn't be doing the test displayed on the waveform? The atmega328 has version 1.11k according to the end of the self calibration routine.

The tester runs several checks to detect the component type and the capacitor check is done at the end. What you saw isn't probably part of the capacitance measurement but some other test done before the capacitance check.

Quote
What is the procedure to access this menu?

For the k-firmware it's a long key press (>500ms).
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 28, 2014, 12:24:29 am
The tester runs several checks to detect the component type and the capacitor check is done at the end. What you saw isn't probably part of the capacitance measurement but some other test done before the capacitance check.

Would your "m" firmware 1.15m act any differently?

Quote
For the k-firmware it's a long key press (>500ms).

I can't seem to access it at all and holding down the button for too long gives a timeout error. Maybe the Chinese have started to disable that menu by modifying the code before flashing the uC.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 28, 2014, 02:06:08 am
Would your "m" firmware 1.15m act any differently?

A little bit different, but mostly the same.

Quote
I can't seem to access it at all and holding down the button for too long gives a timeout error. Maybe the Chinese have started to disable that menu by modifying the code before flashing the uC.

The menu was added in 1.10k and is enabled with the WITH_MENU option in the Makefile.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on September 28, 2014, 09:45:21 am
I can't seem to access it at all and holding down the button for too long gives a timeout error. Maybe the Chinese have started to disable that menu by modifying the code before flashing the uC.

Sometimes it's just a matter of timing.

"Timeout!" should probably say "Shutting down..." or something similar instead, by the way. It describes the event perfectly, but not the action that's being taken.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on September 28, 2014, 11:57:31 am
Yeah its definitely not been enabled on this unit.

I've spent a good 30 minutes finger blasting the test button for different intervals but nothing comes up.

I am wondering since I don't have the correct hardware to program the atmega328, would it be possible to use an arduino uno to do the job of programmer instead?
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on September 28, 2014, 02:48:54 pm
I don't have an Arduino, but I'd be surprised if you couldn't. Have a look at this: Programming AVR with Arduino (http://www.youtube.com/watch?v=_ZL-YNOH_jA#ws).
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 28, 2014, 05:53:31 pm
Yes, every Arduino can be used as an in-system programmer (ISP) for Atmegas. The board of your tester must have a programming header, though. If it doesn't, you need to botch wire directly onto the pins your tester's microcontroller.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 29, 2014, 11:39:54 am
Hi:
I purchased this meter:http://www.ebay.com/itm/291041497713?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
and purchased a  ATmega328P-PU with Arduino UNO bootloader.
I went through the postings here and found postings as to what to burn on the chip. Not quite up on this as a few mentioned opened several file and options and I have no idea which one to pick and if there is anything else to do? Also there has been mention of the fuses to set. On my pick programmer I knew where to set these.  I downloaded WinAVR and don't quite know where  to set them if I could find them!
Any help would be appreciated.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: Richard Crowley on September 29, 2014, 12:48:40 pm
You have not explained WHAT you are attempting to do?
The kit comes with a pre-programmed microcontroller, so WHY do think you want to re-blast the firmware?
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 29, 2014, 12:58:00 pm
I want to make sure it is updated.
Thanks
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 29, 2014, 04:24:55 pm
Connect all three testpoints toghether with a wires, then press the button on your tester. This will start a selftest. Follow the instructions on the LCD (at some point you might have to disconnect the wires again and/or put a capacitor on the test points). At the end of the selftest your unit will display its firmware version, e.g. "1.10k". Then you'll see if it is up to date.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 29, 2014, 04:58:28 pm
Hi:
It's 1.11

I have an atmel328p and trying to use WinAVR with a Sparkfun  Pocket avr programmer. I am new to this and need or would like some help if you can.
Thanks
Don

I pulled out the Make file and loaded it into WinAVR and I think that is the one to use?
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on September 29, 2014, 05:48:21 pm
There's two versions of the software. Latest Markus version would be 1.15m (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/). Karl-Heiz's firmware has the version 1.11k.

I never used winavr, but with Avrdude and GNUmake installed you can do it all from command line. First you need to know your hardware. The most important stuff being:

You have an atmega328p so -> PARTNO=m328p
What type of LCD do you use?
Is there a crystal on your board?
Do you have a bunch of transistors in your battery power circuit?
Is there a voltage divider measuring the battery voltage?
The pocket avr programmer is based on the usbtiny so -> PROGRAMMER=usbtiny and PORT=usb

According to that, you'll need to set the Makefile options. Did you read the Makefile (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328/) and the documentation (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/?view=tar)? You'll also need to be more specific about your problems. We can't really guide you through what to do, if you just say 'I don't know winavr'. Try it, and then tell us, what did and didn't work. Be very careful with the fuse bits or you risk bricking your controller.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on September 29, 2014, 07:47:51 pm
Then most likely you have Markus' firmware. Latest version would be 1.15m (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/). Karl-Heiz's firmware has the version 1.10k.

Just a small hint ;) Karl-Heinz' trunk version (current version under development) is 1.11k.
Title: Re: $20 LCR ESR Transistor checker project
Post by: amtpdb on September 30, 2014, 04:23:56 am
Thanks for getting back.
I'll give it a try and see what happens.
Thanks again.
Don
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on October 03, 2014, 08:06:31 pm
I don't have an Arduino, but I'd be surprised if you couldn't. Have a look at this: Programming AVR with Arduino (http://www.youtube.com/watch?v=_ZL-YNOH_jA#ws).
Thanks I will have a look into it.

That's a good idea! I always encourage contributors and users to send bug reports, add-ons, modifications and so on.

How about having a buzzer that gives a small chime when the component is done being tested like on the peak atlas series. I'm guessing all it would need is for one of the chips outputs to pulse high once or twice for a couple hundred milliseconds.

http://youtu.be/8EXcN9kUwUc?t=15m28s (http://youtu.be/8EXcN9kUwUc?t=15m28s) its from 15:28 if the youtube autotime function doesn't work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 03, 2014, 09:27:22 pm
How about having a buzzer that gives a small chime when the component is done being tested like on the peak atlas series. I'm guessing all it would need is for one of the chips outputs to pulse high once or twice for a couple hundred milliseconds.

Could be useful for large electrolytic caps when the tester needs some time for the measurement. For all other components the tests are quite fast. If you like to have a buzzer please design an add-on and write the code driving the buzzer. That would be a good way to start with MCUs ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: hutale on October 08, 2014, 07:06:09 am
There is an LCR 2.9 bridge, meter kit with video found at http://youtu.be/ZQ33AR1ffFI (http://youtu.be/ZQ33AR1ffFI) and doc at http://lcr.is-best.net/en/ (http://lcr.is-best.net/en/) . This is a LCR/RLC/in-circuit C/ESR meter measuring L/C/R/Z/Rs/ESR/X/Q/D/Phase angle with 100Hz/1kHz/10kHz sine test signals, base on auto-balancing bridge technique. Maybe you are interested in it too.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Richard Crowley on October 08, 2014, 07:38:29 am
All three of those gadgets on Dr. Le Hung's website look interesting to me.
But he doesn't appear to be actively selling them.  Or at least there is no indication on his web pages.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Alex1 on October 08, 2014, 09:06:22 pm
All three of those gadgets on Dr. Le Hung's website look interesting to me.
But he doesn't appear to be actively selling them.  Or at least there is no indication on his web pages.

He does have a "get one" page but it looks like you need to email him about purchasing one.

http://lcr.is-best.net/en/build.htm (http://lcr.is-best.net/en/build.htm)
Title: Re: $20 LCR ESR Transistor checker project
Post by: diogoc on October 10, 2014, 12:47:31 am
It is possible to use the open source code in this chinese copy with graphic display?
http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html (http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 10, 2014, 06:56:10 am
It is possible to use the open source code in this chinese copy with graphic display?
http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html (http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html)

Not without a lot of work and possible board modifications.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on October 10, 2014, 10:56:54 am
...possible board modifications.

What do you have in mind?
Title: Re: $20 LCR ESR Transistor checker project
Post by: diogoc on October 10, 2014, 06:43:04 pm
The schematic should be similar, so only need a firmware with fonts and graphics compatible with that lcd
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 10, 2014, 11:18:42 pm
It is possible to use the open source code in this chinese copy with graphic display?
http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html (http://www.aliexpress.com/item/Small-LCD-Transistor-Tester-Capacitance-ESR-Meter-Diode-Triode-MOS-LCR-NPN/1882283481.html)

The k-firmware supports ST7565 compatible displays, but I don't know which controller the display of that clone got.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on October 11, 2014, 11:59:13 am
That LCD looks small... could it be a Nokia? There was an early attempt (https://translate.google.com/translate?sl=ru&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fvrtp.ru%2Findex.php%3Fshowtopic%3D16451%26st%3D330&edit-text=&act=url) to use such a display.
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrija on October 13, 2014, 05:28:00 pm
I bought the graphical LCD version from EBay (fish...) that I stumbled upon while doing some other shopping and before I knew what it was and where it originated from. Now that I've read good part of this thread, I don't think I want to mess around with mine. I wouldn't mind buying another one, though, with the intention of being able to update its firmware. Looking at the documentation of the original project, there is a version for ATMega644 or 1284; there are schematics in that pdf and everything. Has crystal measurements (I think), DC-DC for Zener (again, I think), input protection with rail-to-rail zeners and tons of more parts than the one I've got, which doesn't have much more than a few R, a few C and uC and screen. But no one seems to be talking about it (ATMega644)? Does this actually exist (there seems to be code for it)? Can I buy it? Or do I need to design a PCB for it myself (if the software already exist, that's a viable option for me).
Title: Re: $20 LCR ESR Transistor checker project
Post by: diogoc on October 13, 2014, 07:53:41 pm
That LCD looks small... could it be a Nokia? There was an early attempt (https://translate.google.com/translate?sl=ru&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fvrtp.ru%2Findex.php%3Fshowtopic%3D16451%26st%3D330&edit-text=&act=url) to use such a display.

Is not a nokia lcd because this have a resolution of 128x64.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 14, 2014, 06:00:28 am
Looking at the documentation of the original project, there is a version for ATMega644 or 1284; there are schematics in that pdf and everything. Has crystal measurements (I think), DC-DC for Zener (again, I think), input protection with rail-to-rail zeners and tons of more parts than the one I've got, which doesn't have much more than a few R, a few C and uC and screen. But no one seems to be talking about it (ATMega644)? Does this actually exist (there seems to be code for it)? Can I buy it? Or do I need to design a PCB for it myself (if the software already exist, that's a viable option for me).

I haven't seen any clone with an ATmega644 yet, so you're welcome to make a PCB yourself ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: a1976888 on October 15, 2014, 04:12:36 am
Hi,
I was looking for a cheap ESR meter to make in circuit capacitor tests.
Could someone who bought any of these tell me if this function is usable in real word repairing tasks, please ?
Which model did you buy ?
Thanks!

PS : Wonderful project !  :clap:
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 15, 2014, 08:37:15 am
I was looking for a cheap ESR meter to make in circuit capacitor tests.
Could someone who bought any of these tell me if this function is usable in real word repairing tasks, please ? Which model did you buy ? Thanks!

The ESR measurement can be used to tell you if the capacitor is failing even if the capacitance measures within spec. As for in-circuit testing your mileage may vary, it's highly dependent on the circuit your testing. This will not discharge your capacitor prior to testing. Nor do they offer input protection (at least last time I looked).

These $20 meters measure resistance and semiconductors as well as capacitance and ESR. They aren't really a replacement for the handheld meters (DER EE DE-5000 - great value) or more expensive proper bench top LCR meters which may offer larger measurement ranges and more accuracy. More expensive meters may be able to take 4 wire measurements for better accuracy.

In addition to capacitance value and ESR (equivalent series resistance) there is also Q (quality factor) which is its efficiency at frequency or inverse of D (dissipation factor). There is also IR (insulation resistance) which is the capacitors ability to withstand current leakage.  Using deduction combined with a multimeter and capacitance/ESR meter should get you through 95% of situations.

There is no best Chinese ESR meter as there is negative aspects in all of them. such as no programming header, no crystal, no external power, less accurate, bad connector design, shortcuts. So take your pick it's only $20.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on October 15, 2014, 08:55:11 am
PS : Wonderful project !  :clap:

FYI the project is actually on this German website:
http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester)

When you buy a Chinese $20 clone in most cases your really buying the project where it was at a few years ago. You can modify and upgrade them if you have the skill, but the reason why they are so popular is they are dirt cheap.
Title: Re: $20 LCR ESR Transistor checker project
Post by: i4004 on October 15, 2014, 12:52:53 pm
All three of those gadgets on Dr. Le Hung's website look interesting to me.
But he doesn't appear to be actively selling them.  Or at least there is no indication on his web pages.

He does have a "get one" page but it looks like you need to email him about purchasing one.

http://lcr.is-best.net/en/build.htm (http://lcr.is-best.net/en/build.htm)

yeap, about 55eur in europe for meters (55eur each)..dunno about reflow controller....that would be about 70$ but dunno how much more for shipping to usa or elsewhere...ask him...he's a good guy.

the soldering on the meter pics i got looks very nice...
Title: Re: $20 LCR ESR Transistor checker project
Post by: a1976888 on October 15, 2014, 11:38:43 pm
I was looking for a cheap ESR meter to make in circuit capacitor tests.
Could someone who bought any of these tell me if this function is usable in real word repairing tasks, please ? Which model did you buy ? Thanks!

The ESR measurement can be used to tell you if the capacitor is failing even if the capacitance measures within spec. As for in-circuit testing your mileage may vary, it's highly dependent on the circuit your testing. This will not discharge your capacitor prior to testing. Nor do they offer input protection (at least last time I looked).

These $20 meters measure resistance and semiconductors as well as capacitance and ESR. They aren't really a replacement for the handheld meters (DER EE DE-5000 - great value) or more expensive proper bench top LCR meters which may offer larger measurement ranges and more accuracy. More expensive meters may be able to take 4 wire measurements for better accuracy.

In addition to capacitance value and ESR (equivalent series resistance) there is also Q (quality factor) which is its efficiency at frequency or inverse of D (dissipation factor). There is also IR (insulation resistance) which is the capacitors ability to withstand current leakage.  Using deduction combined with a multimeter and capacitance/ESR meter should get you through 95% of situations.

There is no best Chinese ESR meter as there is negative aspects in all of them. such as no programming header, no crystal, no external power, less accurate, bad connector design, shortcuts. So take your pick it's only $20.

Thanks for your clear answer.
I think that limitations you pointed out are ok for 20$.
I already have a DMM with capacitance measurement capabilites but I thinks that deduction plus capacitance measure are not enough to surely identify bad caps. It's the reason why I think I need at least en ESR meter to do that. And in circuit testing would be a really nice feature...

As per Chinese ESR meter I'd like to buy a model that could be upgraded with project improvements. No external power, accuracy and shortcuts would be no problem as I could fix them by myself. But crystal and programming header would be nice (or at least a socket 328)...

This one look nice (crystal, socket, large display, upgradable?) :
http://www.aliexpress.com/item/12864-LCD-GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-Free-shipping/2052241237.html (http://www.aliexpress.com/item/12864-LCD-GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-Free-shipping/2052241237.html)
Title: Re: $20 LCR ESR Transistor checker project
Post by: a1976888 on October 15, 2014, 11:40:46 pm
PS : Wonderful project !  :clap:

FYI the project is actually on this German website:
http://www.mikrocontroller.net/articles/AVR_Transistortester (http://www.mikrocontroller.net/articles/AVR_Transistortester)

When you buy a Chinese $20 clone in most cases your really buying the project where it was at a few years ago. You can modify and upgrade them if you have the skill, but the reason why they are so popular is they are dirt cheap.

Are you talking about lacks of hardware or software ?

Thanks for the project link !
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrija on October 29, 2014, 03:12:09 pm
I am looking at the extended version schematics with ATmega644 and there are a few things I don't get. First, why do they say the DC-DC converter should be on a separate board? I am not even sure how would that work as they don't specify what exactly should be on that other board, I guess the whole section with the "button" and battery being the only inputs and TP5 (external test) being output; but why? Second, what do they mean by "button" annotation? Just a name for that connection point or is there supposed to be something else there?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on October 30, 2014, 04:00:34 am
I am looking at the extended version schematics with ATmega644 and there are a few things I don't get. First, why do they say the DC-DC converter should be on a separate board? I am not even sure how would that work as they don't specify what exactly should be on that other board, I guess the whole section with the "button" and battery being the only inputs and TP5 (external test) being output; but why?

The idea is to keep the switching noise away from the test pins. It doesn't need to be another PCB, just have it separated from the main circuit. I've got two boards with DC-DC converters on the same PCB and got no issues so far (one board with a DC-DC converter module and the second one with a classic boost converter). Also I really recommend to have a dedicated LDO for the DC-DC converter. Otherwise it would cause some trouble to the 5V of the main circuit (voltage drop when button is pressed and triggering the MCU's brown-out-detection).

Quote
Second, what do they mean by "button" annotation? Just a name for that connection point or is there supposed to be something else there?

Seems to be just an annotation.
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrija on November 01, 2014, 11:52:14 am
Thanks, I concur with what you are saying. Regarding separate regulator for the DC-DC, the extended schematics does have its own MCP1702-5 so it should be ok.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on November 19, 2014, 02:41:57 am
I have noticed something interesting about the tester. I have mine set to show me several measurements in a row. When I just turn it on normally, the measurement results stay on for a short while, and then another measurement is performed. If I go to the menu and choose Transistor to go back to normal operation, the result stays on the screen longer! Or at least it feels like it stays longer. How much longer, I don't know, seems somewhat random. I actually like this bug. I think there should be an easy way to be able to tell the tester to have the result on the screen for a longer or shorter time (a menu option, along with turning on and off nano for caps?).

Has anyone else noticed this?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 19, 2014, 04:59:06 am
I have noticed something interesting about the tester. I have mine set to show me several measurements in a row. When I just turn in on normally, the measurement results stay on for a short while, and then another measurement is performed. If I go to the menu and choose Transistor to go back to normal operation, the result stays on the screen longer! Or at least it feels like it stays longer. How much longer, I don't know, seems somewhat random. I actually like this bug. I think there should be an easy way to be able to tell the tester to have the result on the screen for a longer or shorter time (a menu option, along with turning on and off nano for caps?).

Please try to press the test button a little bit longer when powering on the tester.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on November 19, 2014, 05:18:27 am
What for?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 19, 2014, 05:52:43 am
What for?

For a longer display period.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on November 19, 2014, 06:02:21 am
I didn't know about that, thanks. Undocumented feature? Doesn't seem to make a difference in my case though. Hard to do, too, because if I hold it a fraction of a second too long it just goes into the menu. Using 1.11k r355 by the way.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 19, 2014, 06:44:13 am
I didn't know about that, thanks. Undocumented feature? Doesn't seem to make a difference in my case though. Hard to do, too, because if I hold it a fraction of a second too long it just goes into the menu. Using 1.11k r355 by the way.

IIRC it's 300ms for the extended display period and 600ms for the menu.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on November 19, 2014, 07:20:30 am
Thank you, that really helps. I finally managed to get the timing right. :-/O Looks like half the time I tend to press the button longer when I exit the menu than I do when turning on the device. It sure feels like a bug though if you don't know that it's a feature.

Oh, and there's really no need to "QFT" each of my posts. I rarely make such significant changes to them that would warrant it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: icpart on November 22, 2014, 05:27:54 pm


As per Chinese ESR meter I'd like to buy a model that could be upgraded with project improvements. No external power, accuracy and shortcuts would be no problem as I could fix them by myself. But crystal and programming header would be nice (or at least a socket 328)...

This one look nice (crystal, socket, large display, upgradable?) :
http://www.aliexpress.com/item/12864-LCD-GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-Free-shipping/2052241237.html (http://www.aliexpress.com/item/12864-LCD-GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-Free-shipping/2052241237.html)
I bought this tester and when it arrives I can do  short review here in the forum. Also I want to make some test with it for software upgrade and 16x2 LCD Panel.
Title: Re: $20 LCR ESR Transistor checker project
Post by: janengelbrecht on November 22, 2014, 05:35:59 pm
I Have this one http://www.aliexpress.com/item/frss-shipping-5pcs-latest-Version-Mega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter/1778135807.html (http://www.aliexpress.com/item/frss-shipping-5pcs-latest-Version-Mega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter/1778135807.html) same software execpt for display part. Would appriciate information on how to to upgrade firmware :) I Have the old software for a 2 line alphanumeric display. But my hardware is with a graphical LCD display (newer version!): here it is - feel free to collect it : https://app.box.com/s/rj03grtur3xonxi7mzud (https://app.box.com/s/rj03grtur3xonxi7mzud)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on November 23, 2014, 03:49:33 am
I Have this one http://www.aliexpress.com/item/frss-shipping-5pcs-latest-Version-Mega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter/1778135807.html (http://www.aliexpress.com/item/frss-shipping-5pcs-latest-Version-Mega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter/1778135807.html) same software execpt for display part. Would appriciate information on how to to upgrade firmware :) I Have the old software for a 2 line alphanumeric display. But my hardware is with a graphical LCD display (newer version!): here it is - feel free to collect it : https://app.box.com/s/rj03grtur3xonxi7mzud (https://app.box.com/s/rj03grtur3xonxi7mzud)

If the display is ST7565 compatible you can use the k-firmware. Otherwise you got bad luck and have to stick with the cloner's firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: briselec on December 04, 2014, 07:32:48 am
nothing obvious at mikrocontroller.net site. i dont speak german and like many diy hobbyists not good with code suppositories. 

I want to know where I can get code suppositories.
That would make me a genuine smart arse   :-DD
Title: Re: $20 LCR ESR Transistor checker project
Post by: con-f-use on December 04, 2014, 07:45:01 am
Grave diggin' are we? April 1st.
Title: Re: $20 LCR ESR Transistor checker project
Post by: magnetus on December 13, 2014, 08:55:00 am
can anyone help me please?

i got a Chinese transistor tester and tried to update it using the k-firmware now no screen wont display anything. i got the transistor tester 2014-07 by fish8840

thanks
Title: Re: $20 LCR ESR Transistor checker project
Post by: andrija on December 13, 2014, 09:19:40 am
can anyone help me please?

i got a Chinese transistor tester and tried to update it using the k-firmware now no screen wont display anything. i got the transistor tester 2014-07 by fish8840

thanks

As explained earlier in the thread, many Chinese testers - and the one you mentioned in particular, which I also have myself - use different hardware with which they supply their own, customer, modified firmware. You CAN'T use the vanilla "official" firmware with that.
Title: Re: $20 LCR ESR Transistor checker project
Post by: magnetus on December 13, 2014, 11:47:36 am

[/quote]

As explained earlier in the thread, many Chinese testers - and the one you mentioned in particular, which I also have myself - use different hardware with which they supply their own, customer, modified firmware. You CAN'T use the vanilla "official" firmware with that.
[/quote]

thanks for the input. I installed a HD4480 LCD and it works ok now.
now this display is 16x2
can i use a 20x4?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 13, 2014, 10:14:27 pm
thanks for the input. I installed a HD4480 LCD and it works ok now.
now this display is 16x2
can i use a 20x4?

Yes, but the extra screen estate is used for displaying debugging information mostly (if enabled). AFAIR, supporting 20x4 text displays for the UI is on the to-do list. If you like to have a graphical display, get a ST7565 compatible one.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 22, 2014, 11:32:48 am
Sorry to be asking about a rather old posting in this lengthy thread. I have a board that is almost identical to the one shown in the picture from the posting below. The only difference I can see is the binding posts that mine doesn't have.

I replaced the zener with the 2.5V reference and everything works OK. When I replaced the 78L05 with the recommended LDO regulator, the board still works, but now reports that the 9V battery is low, at 7V. Yes, I did take into account the different pinout between parts.

Other than the added bypass caps, I don't see from the picture that any other part changes were made. Can anyone tell me why the LDO isn't working like it should? For now, I have put the 78L05 back.


Here is my early version of the new Tester with some modifications.
The 10-pin ISP header is soldered, but one side of the frame must be cut out
to match the room left for the header.
The original potentiometer has been replaced to a exemplar with higher resistance
(10k) to save power.
Two blocking capacitors of 100nF each are additionally mounted near the ATmega.
The D1 zener diode is replaced by a precision voltage reference like LM4040AIZ2.5 .
If you don't have a precision voltage reference, you should remove the zener diode at least.
I had also replaced the original 78L05 regulator by my preferred MCP1702-5002 regulator,
because this regulator can also save quiescent current.
Regards, Karl-Heinz
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on December 22, 2014, 01:06:59 pm
Is it also getting warm? Whenever a regulator does this to me, it's usually because it doesn't like the capacitors on its input or output. The great thing about 78L05 is that it's stable under the same conditions that would make other ones oscillate like crazy. HTH
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 22, 2014, 02:16:40 pm
I bought the graphical LCD version from EBay (fish...)

I think I bought the same thing. This is what I ordered: http://www.ebay.com/itm/111329306664. (http://www.ebay.com/itm/111329306664.) What I received has the same circuit board, but the LCD is mounted a bit differently. I'm pretty sure that it is an ST7565, as the backside of the display board is marked with SPI signal names.

I already have one of the 16x2 LCD testers that I bought some time ago. Although listed as having an ATmega328P, it actually has an ATmega168 (SMD). The part number was sanded off and the lock bits were set (jerks). After soldering on an ICSP header, I manged to erase the chip and update it to 1.11k.

So, I decided to go for broke and see about updating the graphic version that I just got. It also needed a header (out the back of the board for the correct pinout), but this one did not appear to be locked. I made a backup of the firmware, then flashed the ST7565 1.11K firmware.

Things didn't go so well this time. I do get text on the screen, but it looks mirrored and upside down. It also looks too large and ghosted. Obviously, there are some differences between the standard firmware and/or hardware and what this Chinese guy made. I can't go back to the original firmware, because AVRDUDE says the file is corrupt.

If anyone figures out how to update this board, please let me know.
Title: Re: $20 LCR ESR Transistor checker project
Post by: johnh on December 22, 2014, 04:29:56 pm
This listing (111329306664.) has been removed, or this item is not available.

        Please check that you've entered the correct item number
        Listings that have ended 90 or more days ago will not be available for viewing.



Do have a image of the item you bought
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on December 22, 2014, 04:36:27 pm
The period shouldn't be part of the link:

111329306664 (http://www.ebay.com/itm/111329306664)
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 22, 2014, 04:37:56 pm
I probably mis-copied the item number. I attached a picture. It doesn't show in the Preview. Hopefully you can view it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 22, 2014, 04:41:07 pm
The period shouldn't be part of the link:

111329306664 (http://www.ebay.com/itm/111329306664)

Thank you. My mistake. The listing of the one with the blue circuit boards is where I ordered from. What I received has red boards, as the picture I just posted. What I have has the blue backlight and white characters. From what I read here, that is supposed to be newer than the one with the green LCD.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 22, 2014, 04:43:35 pm
Is it also getting warm? Whenever a regulator does this to me, it's usually because it doesn't like the capacitors on its input or output. The great thing about 78L05 is that it's stable under the same conditions that would make other ones oscillate like crazy. HTH

I didn't think about checking the temperature when I had the LDO installed. I have since put a 78L05 back. I may leave it this way for a while. I have other projects that need attention. I did replace the voltage reference, so that should be an improvement.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 22, 2014, 11:57:37 pm
I replaced the zener with the 2.5V reference and everything works OK. When I replaced the 78L05 with the recommended LDO regulator, the board still works, but now reports that the 9V battery is low, at 7V. Yes, I did take into account the different pinout between parts.

Have you checked the battery voltage and Vcc (+5V) with a DMM?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on December 23, 2014, 12:11:42 am
Things didn't go so well this time. I do get text on the screen, but it looks mirrored and upside down. It also looks too large and ghosted. Obviously, there are some differences between the standard firmware and/or hardware and what this Chinese guy made. I can't go back to the original firmware, because AVRDUDE says the file is corrupt.

If the display got any ID you could try to get the datasheet and check if the display needs some additional or special setup. The problem with the modified clones is that the firmware isn't published. Therefore I recommend to stay away from clones with graphic displays unless they are fully ST7565 compatible.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JoeO on December 23, 2014, 02:15:12 am
The period shouldn't be part of the link:

111329306664 (http://www.ebay.com/itm/111329306664)
The first picture shows that this tester does not give the user a correct representation of the transistor under test.
It shows a BJT transistor but the Vf is 1.27 volts.  This indicates a darlington transistor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 23, 2014, 05:05:59 pm
I replaced the zener with the 2.5V reference and everything works OK. When I replaced the 78L05 with the recommended LDO regulator, the board still works, but now reports that the 9V battery is low, at 7V. Yes, I did take into account the different pinout between parts.

Have you checked the battery voltage and Vcc (+5V) with a DMM?

No, I didn't think of that when I had the LDO installed. I'll check the voltage when I put an LDO back in, later.

Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on December 30, 2014, 10:24:04 am
So, I decided to go for broke and see about updating the graphic version that I just got. It also needed a header (out the back of the board for the correct pinout), but this one did not appear to be locked. I made a backup of the firmware, then flashed the ST7565 1.11K firmware.

Things didn't go so well this time. I do get text on the screen, but it looks mirrored and upside down. It also looks too large and ghosted. Obviously, there are some differences between the standard firmware and/or hardware and what this Chinese guy made. I can't go back to the original firmware, because AVRDUDE says the file is corrupt.

I have bought a slightly different one, that has the advantage of having a atmega328p on a socket
http://www.ebay.fr/itm/181534623115?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.fr/itm/181534623115?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)
I even put a zif support so I can change the processor  easily. I have thus saved the original 328p and
I am playing with a new one and my programmer. 

I have  dowloaded the software from
http://www.mikrocontroller.net/svnbrowser/transistortester/ (http://www.mikrocontroller.net/svnbrowser/transistortester/)

and I am trying to configure the Makefile for my board, but with moderate success up to now.
I have been using  several options, but the one that  seems to work is mega328_st7565
although I have   the same problem of display :  reverse screen, with large and faded fonts.

The screen is marked 12864-1602_V1.1 (2014.08.01)  from EZM Electronics Studio

Can anybody help ?
Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on December 30, 2014, 11:00:11 am
Some progress this will be useful for mojoe :

In the makefile, one  needs to comment the two line s

#CFLAGS += -DLCD_ST7565_H_FLIP=1
#CFLAGS += -DLCD_ST7565_V_FLIP=1

Also the font is better with

CFLAGS += -DFONT_6X8

I have still to correct the contrast

done with
LCD_ST7565_RESISTOR_RATIO = 5
instead of
LCD_ST7565_RESISTOR_RATIO = 4

 and to make it understand that the screen is much larger, or essentially to
add a new line at the end of each line.
Apart from that, it seems to work, with the proper graphics, although I have not fully tested it, and compared with the
original firmware.

Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on December 31, 2014, 12:29:34 am
Here is an update on my experience in using the
mega328_st7565   firmware  from Karl-Heinz Kubbeler v.1.11k on a
ebay cheap ESR meter.

After the modification of the Makefile as I mentioned before,
the  display is OK, but different from the original.

The nice thing of the board I have, is that I could just squeeze a zif socket on the original one.
This was extremely useful for testing various versions of the firmware.

In the attached  pictures, you have in the first three pics the New firmware that I   uploaded,
and in the next two the original firmware display, which is also supposed to be 1.11k,
according to the seller.

The last picture show the setting of the zif socket.

As you see,  the font is the same, but there is a blank line spacing in the original firmware.
I did not find any option to add these blank lines, which makes the output nicer.
Does anybody knows what to do to add these lines, and in general to
make better use of the large LCD display ? 

On the opposite, the "show data" item is missing in the original firmware,
but the version is visible in the selftest : also 1.11k

The nice thing is that I will now be able to upgrade the firmware, and to calibrate the  meter which is a
large improvement with respect to my previous one based on an atmega168 SMD  (with sanded brand).


 
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 31, 2014, 04:41:45 pm
Hey, thanks for posting. I'll have to try what you did on mine and see if it works. Good work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on December 31, 2014, 05:01:40 pm
Since you still have the original firmware, could you read it and post it somewhere so I have a copy? As I mentioned before, what I read from the SMT chip on mine is somehow corrupt and I can't flash it back with avrdude.

Thanks.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on January 02, 2015, 11:27:56 am
Some progress this will be useful for mojoe :

Thanks to your posting, I now have my Fish8840 tester working again. Some of my makefile settings are different than yours.

makefile options:

FLAGS += -DLCD_ST7565_H_OFFSET=4
CFLAGS += -DLCD_ST7565_H_FLIP=1
# CFLAGS += -DLCD_ST7565_V_FLIP=1
CFLAGS += -DFONT_6X8
CFLAGS += -DBAT_NUMERATOR=66 (I measured the battery voltage and it matches with the displayed voltage with this)

To get the double-spaced lines, look in the file lcd-routines.c:

Change:
lcd_set_cursor(1,0)
lcd_set_cursor(2,0)
lcd_set_cursor(3,0)

To:
lcd_set_cursor(2,0);
lcd_set_cursor(4,0);
lcd_set_cursor(6,0)

The only anomaly I have is that although 3 is the best LCD contrast value that works, it really is a bit too light. It seems as though I need a 2.5 or so. The original firmware had the screen contrast set higher.

Joe
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on January 02, 2015, 01:09:52 pm
One more anomaly. The transistor symbol in the lower right corner of the display is too low. Part of it is cut off. I tried setting the line spacing back to single and it makes no difference. There must be another setting to position the symbol. I just have to find it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mojoe on January 02, 2015, 01:36:16 pm
Here is an update on my experience in using the
mega328_st7565   firmware  from Karl-Heinz Kubbeler v.1.11k on a
ebay cheap ESR meter.

When you test a diode or cap, do you get a graphic symbol in the lower right for it, or do you get the character symbol on the first line? For transistors, I get the graphic symbol. For two-terminal devices, I get the character symbol.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on January 02, 2015, 08:56:05 pm
When you test a diode or cap, do you get a graphic symbol in the lower right for it, or do you get the character symbol on the first line? For transistors, I get the graphic symbol. For two-terminal devices, I get the character symbol.

For both the original and the  compiled firmware, I  have diodes, resistors, and capacitors graphics on the first line,
and transistors and mosfets with the graphic.

Thanks for  the lcd lines fix. It works, and now I have the same display as in the original firmware. I do not have to fix the battery voltage, as it is pretty close to the measure (8.6 instead of 8.7).

As you see in my pictures, the graphics is the same in the compiled firmware and the original one.

I believe that  the are some harware differences in the boards, and most probably mine is intended to be very
close to the original design. I did not check the values of the components, but it looks like.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on January 08, 2015, 05:24:30 am
That board looks exactly like the one with 1602. They just slapped a large display on an old design, I think. If it comes with 10-microfarad aluminum caps, it might benefit from replacing those, but otherwise it does follow the original design fairly closely.

I can't quite make it out on the pictures, but I think the offset may need to be set to 0 instead of 4. This type of display benefits from larger fonts, in my experience, but I'd like to make the icons fit in with the larger font... Maybe I'll learn to do that someday.



By the way, I've got another puzzle. I have a coil that's about 7.1 Ohm as measured with a DMM. My TT measures the resistance as 7.1 Ohm correctly. Then I insert a resistor in series to the remaining test point. It measures the resistor correctly, but suddenly thinks that the coil is about 19 Ohm!  |O
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 08, 2015, 11:07:16 pm
By the way, I've got another puzzle. I have a coil that's about 7.1 Ohm as measured with a DMM. My TT measures the resistance as 7.1 Ohm correctly. Then I insert a resistor in series to the remaining test point. It measures the resistor correctly, but suddenly thinks that the coil is about 19 Ohm!  |O

Is the second resistor about 19 - 7.1 = 11.9 Ohms? Does that happen also for any other two resistors?
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on January 09, 2015, 05:05:34 am
No, that would be too easy! It's 100 kilohm. Also tried with 500. Same result. Tried with two different testers, one with 1602 and one with 7565 display. Sometimes the coil's resistance is shown first, sometimes the other resistor's resistance is shown first, seemingly at random.

Seems to happen only with coils, but I don't have small value resistors to check at the moment.
Title: Re: $20 LCR ESR Transistor checker project
Post by: RedOctobyr on January 12, 2015, 10:46:16 am
Whew, this is quite a thread! Read through the whole thing, though that doesn't mean I understood all of it. Tons of great info! Thank you to Karl-Heinz, madires, and everyone who has contributed to this amazing tool/project!

By the way, thank you to the people who mention something like a hardware difference, and then explain the ramifications of the difference :) Just saying that one has a crystal, or doesn't have a 2.5V reference, etc, doesn't tell some of us what that really means, or why it's good/bad. Those kinds of explanations are appreciated  :-+

I just ordered mine, I went with this one:
http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

It's supposed to have the M328 chip, on a socket. I don't know if it can take an ISP header. It has the 2-line display, which should help with firmware compatibility. It lists an 8MHz crystal.

Now for the embarrassingly-easy question (I'm new at all this). One thing I'd like to use it for is in-circuit ESR testing. So I'll need some kind of pointed probes which can also plug into the tester. Presumably into the ZIF socket. Is there anything that's recommended for that?

I'm sure this is incredibly basic, which is why it never even comes up. But I'd like to order other things I'll need, while this is being shipped. And normal multimeter probe bananas will be too fat to plug in, unless I cut their ends off. There is one version (the one with a case) which includes leads, but I don't see much discussion of them apart from that.

As I understand it, I should have an appropriate capacitor available for use during calibration. And I will need to re-read some things to better understand what would be needed to update the firmware (no idea what mine will have, but almost certainly an old version; the listing says 2013 software).
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 13, 2015, 12:40:53 am
Now for the embarrassingly-easy question (I'm new at all this). One thing I'd like to use it for is in-circuit ESR testing. So I'll need some kind of pointed probes which can also plug into the tester. Presumably into the ZIF socket. Is there anything that's recommended for that?

I'm sure this is incredibly basic, which is why it never even comes up. But I'd like to order other things I'll need, while this is being shipped. And normal multimeter probe bananas will be too fat to plug in, unless I cut their ends off. There is one version (the one with a case) which includes leads, but I don't see much discussion of them apart from that.

Maybe some multimeter probes soldered to a pin header matching the ZIF socket. Add some heat shrink and have fun.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 13, 2015, 02:24:03 am
No, that would be too easy! It's 100 kilohm. Also tried with 500. Same result. Tried with two different testers, one with 1602 and one with 7565 display. Sometimes the coil's resistance is shown first, sometimes the other resistor's resistance is shown first, seemingly at random.

Seems to happen only with coils, but I don't have small value resistors to check at the moment.

Thanks! I'm able to reproduce that issue with the k-firmware. For a 1mH coil the difference is minimal but for a 15mH coil it's 142 Ohms (with a 1k and 100k resistor).

Update: The issue seems to occur if the resistance of the coil is < 10 Ohms.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on January 13, 2015, 08:10:07 am
Thank you for looking into this. BTW, unrelated, but might be something for Karl-Heinz to look at for the next update, there's a new (I think) icon for bipolar transistors with a protection diode. If I use a transistor without a diode and add a diode to it in the "wrong" direction, this is reflected inline, but the icon remains the same. Kind of strange to look at. Not that it's a normal condition, of course, but still...

It's supposed to have the M328 chip, on a socket. I don't know if it can take an ISP header. It has the 2-line display, which should help with firmware compatibility. It lists an 8MHz crystal.

Now for the embarrassingly-easy question (I'm new at all this). One thing I'd like to use it for is in-circuit ESR testing. So I'll need some kind of pointed probes which can also plug into the tester. Presumably into the ZIF socket. Is there anything that's recommended for that?

I'm sure this is incredibly basic, which is why it never even comes up. But I'd like to order other things I'll need, while this is being shipped. And normal multimeter probe bananas will be too fat to plug in, unless I cut their ends off. There is one version (the one with a case) which includes leads, but I don't see much discussion of them apart from that.

As I understand it, I should have an appropriate capacitor available for use during calibration. And I will need to re-read some things to better understand what would be needed to update the firmware (no idea what mine will have, but almost certainly an old version; the listing says 2013 software).
That one looks just like the one I have, seems pretty popular. It has no ISP header nor pads for it. But the chip is removable, so the header is not really needed all that much if you're just going to update the firmware once in a blue moon.

I don't see why someone would buy a "naked" version now that ones with a case are available. I bought it for the sole purpose of mercilessly experimenting with the hardware, but if I needed one for just testing components, I'd get one with a case for sure. The one you mentioned is  the one with a blue case (http://item.taobao.com/item.htm?spm=a1z10.1-c.w4004-737437924.12.q4COnL&id=17620914059), right? I believe it's very similar internally to what you have ordered. A quick overview of what's available on the famous auction site has shown that these also might come with leads: Mega328 Transistor Tester Diode Triode inductor Capacitance ESR Meter LCR LED (http://www.ebay.com/itm/Mega328-Transistor-Tester-Diode-Triode-inductor-Capacitance-ESR-Meter-LCR-LED-/281549885699?pt=LH_DefaultDomain_0&hash=item418dae5103) and ATmega328 version inductor-capacitor ESR Transistor tester meter Digital lcd (http://www.ebay.com/itm/ATmega328-version-inductor-capacitor-ESR-Transistor-tester-meter-Digital-lcd-/111553911569?pt=LH_DefaultDomain_0&hash=item19f9219b11). If I were to get one for everyday use, it would probably be this: M328 transistor tester can be measured LCR / transistor / MOSFET / SCR (http://www.ebay.com/itm/M328-transistor-tester-can-be-measured-LCR-transistor-MOSFET-SCR-/321595001808?pt=LH_DefaultDomain_0&hash=item4ae08e4bd0) (spelling and grammatical errors are courtesy of the sellers). It can take leads and also has the frequency option. Doesn't seem to come with leads though.

This is not something I'd recommend someone to do, but for quick makeshift test leads that fit into a ZIF socket I use flexible breadboard jumpers (http://www.amazon.com/Solderless-Breadboard-Jumper-Cable-Qty75/dp/B0043LTD3M).

I'd go with what madires (http://www.eevblog.com/forum/profile/?u=25360) advised for now. I would try to use leads that are as short as possible to minimize stray capacitance and lead resistance.

As for the capacitor, as I understand it, your only concern should be that it's above 100nF and has the least possible amount of leakage. Nothing too special is required for calibration, which is one of the reasons I like this project so much.
Title: Re: $20 LCR ESR Transistor checker project
Post by: RedOctobyr on January 13, 2015, 11:59:30 am
madires, hapless, thank you both for the feedback. hapless, that last tester you linked to (with frequency functions) looks pretty nice. But I'll start with what I ordered, and see how that works for me. I'm guessing it'll be fine for my current purposes.

If I may ask, since mine is apparently like yours, are there modifications that I should plan on doing to it? I don't know if this design is missing something important. ESR/capacitance checking is what I forsee for uses at the moment, for trying to help troubleshoot issues.

I'll probably try multimeter leads to start, maybe cutting down their length if needed. The mention of flexible breadboard jumpers made me realize maybe I could use some similar small cables I have sitting around, thanks  :-+
Title: Re: $20 LCR ESR Transistor checker project
Post by: Halfdead on January 13, 2015, 06:34:40 pm
Has anyone else had their tester die?
 :-BROKE

I think the ATMEGA328P in my unit died, the unit draws over 200mA when turned on and the display doesn't power on properly, the display goes to nearly full brightness when you power the unit on and then dims very low nearly instantly after.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 14, 2015, 12:00:54 am
Update: The issue seems to occur if the resistance of the coil is < 10 Ohms.

I've discussed that with Karl-Heinz. The cause of the issue is the ESR measurement which is also used to measure resistances less than 10 Ohms in the k-firmware. The measurement method doesn't deliver valid results for inductors. If an inductor is detected the low resistance measurement is skipped. And since the check for inductors is performed only if one single component is tested, an inductor and a resistor connected to all three probes are detected as two resistors. In that case the low resistance measurement is run and you'll see the wrong resistance value for the inductor. The m-firmware uses a different method for low resistance measurements (dedicated function) which also runs fine for inductors, but I don't know if Karl-Heinz will add it to the k-firmware (flash size constraints).
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on January 14, 2015, 04:02:59 am
Interesting. So, if I use a low-value wirewound potentiometer and insert all three leads, it will not show the correct results? This is definitely something to be aware of.

How does your function compare to the ESR one in terms of resolution and accuracy? If he decides not to include it, I might just have to make a franken-firmware. I don't compile with UART and I enable the use of EEPROM, so should have enough memory for the modification. I'm also trying to figure out why the code for the frequency generator (function switch_frequency) is so lengthy while looking somewhat repetitive. Maybe folding it into a smaller function will free up some flash, too...

Has anyone else had their tester die?
 :-BROKE

I think the ATMEGA328P in my unit died, the unit draws over 200mA when turned on and the display doesn't power on properly, the display goes to nearly full brightness when you power the unit on and then dims very low nearly instantly after.
Is anything getting hot on the board? If the chip is removable, remove it and power on the unit. If it behaves the same way without the chip, check the regulator and its output capacitor.

If I may ask, since mine is apparently like yours, are there modifications that I should plan on doing to it? I don't know if this design is missing something important. ESR/capacitance checking is what I forsee for uses at the moment, for trying to help troubleshoot issues.
It should work well out of the box, but I would advise replacing those 10-microfarad capacitors with something better. On the output side of the regulator you may want to put a tantalum capacitor of about twice as much capacitance, and the one blocking the battery can be about 10 times higher. Mine are 47 and 100 respectively, but 47 might be a little overkill. This will improve the stability of the regulator and make the results a little more repeatable. Other than that, all modifications are totally optional. I like having a 2.5V voltage reference and a 1nF cap on the aref pin. Neither seems to affect the numbers too much for me though.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Halfdead on January 14, 2015, 08:23:11 pm
I removed the ATMEGA328P and the current drawn goes down to about 7 mA which seems reasonable and the display is now at full brightness but displaying gibberish as to be expected.


I think it's just a dead ATMEGA328P, but I've no idea how it died or where to get replacement firmware that's compatible with this unit.

Has anyone else had their tester die?
 :-BROKE

I think the ATMEGA328P in my unit died, the unit draws over 200mA when turned on and the display doesn't power on properly, the display goes to nearly full brightness when you power the unit on and then dims very low nearly instantly after.
Is anything getting hot on the board? If the chip is removable, remove it and power on the unit. If it behaves the same way without the chip, check the regulator and its output capacitor.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 14, 2015, 11:35:37 pm
Interesting. So, if I use a low-value wirewound potentiometer and insert all three leads, it will not show the correct results? This is definitely something to be aware of.

The displayed values for the potentiometer will be fine. Only if you add an inductor of a few mH or more the tester will show the wrong resistance value for that inductor. But if you got just the inductor connected to the probes the resistance diplayed will fine again.

How does your function compare to the ESR one in terms of resolution and accuracy? If he decides not to include it, I might just have to make a franken-firmware. I don't compile with UART and I enable the use of EEPROM, so should have enough memory for the modification. I'm also trying to figure out why the code for the frequency generator (function switch_frequency) is so lengthy while looking somewhat repetitive. Maybe folding it into a smaller function will free up some flash, too...

The resolution is the same (0.01 Ohms) and accuracy seems to be about the same also. If you use the optional functions I'd recommend to add a rotary encoder for a more convenient UI. In case you got a tester with text display you can run the m-firmware anyway.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on January 15, 2015, 04:24:45 am
Thanks, I actually have a couple of encoders lying in front of me just asking to be connected. Looks like the test button's behavior is automatically modified when the resistor dividers are connected.  8)

TBH, I don't remember what happened. I tried the m-firmware, liked it, then found something that I couldn't live without in k-firmware and switched back.  :-// That was before I even started reading the forums. The problem is probably long gone by now.

I think I'm going to try to lift the function from m-firmware and transplant it into k (unless K.-H. beats me to it, which he probably will if he decides to use it). I wonder if there's a way to contribute back without the use of a versioning system? Maybe by posting diff files somewhere?

Interesting. So, if I use a low-value wirewound potentiometer and insert all three leads, it will not show the correct results? This is definitely something to be aware of.

The displayed values for the potentiometer will be fine. Only if you add an inductor of a few mH or more the tester will show the wrong resistance value for that inductor. But if you got just the inductor connected to the probes the resistance diplayed will fine again.
I see. Thanks for clarifying.

I removed the ATMEGA328P and the current drawn goes down to about 7 mA which seems reasonable and the display is now at full brightness but displaying gibberish as to be expected.


I think it's just a dead ATMEGA328P, but I've no idea how it died or where to get replacement firmware that's compatible with this unit.
This would mostly depend on the display and layout of the board. How about attaching pictures of what you have?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Mafiawarsfourlife4 on January 22, 2015, 04:48:25 am
In case anyone is interested in the graphics versions: they are described and sold within China on a Web site in Chinese only:
http://fish8840.taobao.com/ (http://fish8840.taobao.com/) I prefer to open it in Google Chrome, which offers to translate it automatically, or on a right-click. I don't know whether the many sources of these devices buy from fish8840 (in which case they'd be all be of equal quality) or make their own copies.

Presumably fish8840 is the originator of the Chinese hardware versions (although they themselves may be imitated!), and weiweitm adapted the software. The reason for production of a graphics version given is that a text-only display in Latin characters is difficult for Chinese people, which makes sense; there are traditional and simplified Chinese, and English-language versions. There are two versions, an older one with a green display, and a later one with a slightly larger blue display; both are sold, with the blue one a little more expensive. The pictures don't show a crystal visible on the board; it could be there but hidden. As far as I can tell the later board was released in March 2014; the only software appears to be weiweitm's version 2.1 (with no mention of providing source code). I don't know if there is any provision at all for software updates (socketed chip, header, any intention to produce downloadable updates). There is a picture of an elegantly cased version, branded Yiwanjia, but no indication (such as price) that it exists.

Foreigner Markus F is acknowledged. The translation is difficult to understand in detail; I think Translate's "shelves without shell" are uncased boards!

Web pages of the two hardware versions (Chinese):
Larger screen, blue, backlit 25/3/2014, software shows as 2.1 on pictures:
http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.16.IhvBUf&id=36323329572 (http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.16.IhvBUf&id=36323329572)
Smaller green graphics screen version:
http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.19.IhvBUf&id=37659767669 (http://item.taobao.com/item.htm?spm=a1z10.5.w4002-2323427594.19.IhvBUf&id=37659767669)
i need to repair this transistor tester and i dont know where to start?any help would be great.
Title: Re: $20 LCR ESR Transistor checker project
Post by: RedOctobyr on January 23, 2015, 12:50:44 pm
I just ordered mine, I went with this one:
http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

...
And I will need to re-read some things to better understand what would be needed to update the firmware (no idea what mine will have, but almost certainly an old version; the listing says 2013 software).

Mine arrived today, ordered 11 days ago. I'm pleasantly surprised, I was expecting it to take longer.

Another nice surprise, it has FW 1.11k. That version appears to be dated January 5th, 2015, from what I can see, and my unit was ordered about a week after that. I'm glad they're at least loading current firmware, so I don't have to worry about doing that right away.

I tested some capacitors and resistors that I had sitting around, very cool! A 100 Ohm 2% resistor measured as 98.7 Ohms. I did the calibration routine, using a 10uF capacitor. The readings didn't seem to change meaningfully after the calibration; perhaps it was calibrated before shipping.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on January 23, 2015, 01:20:27 pm
Is there anywhere FW 1.11k can be downloaded?

Never mind, found it. Currently 1.16
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on January 23, 2015, 10:49:35 pm
Is there anywhere FW 1.11k can be downloaded?
1.11k is the current version under development and can be found at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/) (click "Download GNU tarball" at the bottom).

Never mind, found it. Currently 1.16
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/)
That's 1.16m and it supports text displays only. The UI is a little bit different, some tests and measurements are done in a different way, functionality is nearly the same and it offers a few small extras, like detection of TRIACs' MT1 and MT2.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on January 24, 2015, 03:34:25 am
I've ordered one of the text versions, the graphics seemed unnecessary.
Title: Re: $20 LCR ESR Transistor checker project
Post by: rob77 on January 24, 2015, 06:45:53 am
had one atmega644 in DIP40 around...got no other real use for it.. so I’ve built the tester myself with that atmega644 and lm336-2.5 reference and a mc34063 step up to 30V + 1mA current source  for zener testing.
Title: Re: $20 LCR ESR Transistor checker project
Post by: malch on January 28, 2015, 02:33:57 pm
I got the one someone recommended. It works with USB power and no battery. [I had to try it right away]

http://www.youtube.com/watch?x-yt-ts=1422327029&x-yt-cl=84838260&v=UbOMqA2AOIk&feature=player_embedded (http://www.youtube.com/watch?x-yt-ts=1422327029&x-yt-cl=84838260&v=UbOMqA2AOIk&feature=player_embedded)


I think I should have bought one with a 9 volt battery and larger screen, now that I have it in my hand.

Does this use a rechargeable lithium battery?

edit jan 29: Seller replied yes.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Pixel26 on January 29, 2015, 02:19:45 am
Hi,

I just buy a transistor tester 328p:

(http://image.noelshack.com/fichiers/2015/05/1422457535-giuiiu.png)

And i read earlier in this topic, it was possible to flash with this firmware "mega328_st7565" for a better accuracy.

 I really do not know where to enter in Avrdude, can you help for for the fuse parameters please ? I use a Usbasp.  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Pixel26 on January 30, 2015, 09:25:32 am
Hi,

I found what I needed:

Hfuse: 0xD9
Efuse: 0xFC
Lfuse: 0xF7

But for efuse my tester not want this new value, i leave on 0x04.

I also had to change the makefile. My screen is displayed nothing, the values that I changed:


-For blank screen:

LCD_ST7565_RESISTOR_RATIO = 5
CFLAGS += -DFONT_6X8

-For the display back normal to 180 ° I desactivate:

CFLAGS += -DLCD_ST7565_H_FLIP=1
CFLAGS += -DLCD_ST7565_V_FLIP=1

-And for the measurement of the battery voltage, i change value "133" by "66":

CFLAGS += -DBAT_NUMERATOR=66


I noticed that the tester with the backlight consume +- 115 ma !!!  And cutting its power supply consume +- 15ma, much better  :-+


That is, if it can help others.


Ps: sorry for my bad english, I hope so this is a minimum comprehensible  :)




Title: Re: $20 LCR ESR Transistor checker project
Post by: Mr Smiley on January 30, 2015, 04:05:55 pm
Hi,

I found what I needed:

Hfuse: 0xD9
Efuse: 0xFC
Lfuse: 0xF7

But for efuse my tester not want this new value, i leave on 0x04.


I had the same confusing problem with the efuse, asking it to be set to 0xfc gave an error saying it was now showing 0x04.

I went to one of the many on line fuse calculators and put in 0xfc which gave an indication of which fuses where being set. I then put in a value of 0x04 and the result was that the same fuses were set for for 0x04 as they were for 0xfc  :-/O

 :)

Title: Re: $20 LCR ESR Transistor checker project
Post by: jimmc on January 31, 2015, 02:27:06 am
The problem is that the five high bits which are not implemented are being set to '1' by the fuse calculator and read as '0' by the AVRDude.
AND either with 07 (0000 0111) to mask off the unused bits and they're the same

xxxx x100
1111 0100     FC
0000 0100     04

Jim
Title: Re: $20 LCR ESR Transistor checker project
Post by: Danielw on January 31, 2015, 03:10:13 am
What would normally blow up if you by accident connect a charged cap on this? I thought it was the atmega but I tried connect 3,3v direcly to ISP connector and it started up. It is the FISH8840 version I've got.

It does not start up with 9v connected.

Edit: It just started up by itself! :o But stuck at 'testing' and shuts off after only 1-3 sek. Hmmm...

Best regards
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 01, 2015, 01:17:13 am
What would normally blow up if you by accident connect a charged cap on this? I thought it was the atmega but I tried connect 3,3v direcly to ISP connector and it started up. It is the FISH8840 version I've got.

It does not start up with 9v connected.

The Vcc pin of the ISP header is directly connected to the circuit's Vcc. Please see the schematic in Karl-Heinz' documentation at http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/tags/english/) (click "Download GNU tarball" at the bottom).
Title: Re: $20 LCR ESR Transistor checker project
Post by: mmatic on February 02, 2015, 09:15:38 pm
Which one is best buy right now?

This one on the link below?
http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
Title: Re: $20 LCR ESR Transistor checker project
Post by: pukje on February 03, 2015, 12:13:10 am
This weekend i installed winavr, and compiled the source. My hex output has a larger size,
I tested the makefile in the mega328 directory.
The precompiled version is 65783 bytes, my compiled version is 77859 bytes.
( I used the make all option in the programmers notepad).

After that i compiled the software on my centos machine, and that hex file was
also bigger then the original, this hex file was 77622 bytes.
My tester is in the mail, i orderd him last week, so i can't test the hex file
at this moment.

What i'm a doing wrong ???

Title: Re: $20 LCR ESR Transistor checker project
Post by: eas on February 03, 2015, 02:40:29 pm
Which one is best buy right now?

This one on the link below?
http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/251334183807?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)

I ordered from this listing (http://www.ebay.com/itm/171467739124?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT).

It was packed well, shipped quickly and arrived in Seattle less than a week after I ordered it. Its based on the same EZM Studios board as the one you linked to, but fitted with a larger graphical display, which, as I understand it, is supported by the mainline firmware. I haven't tried  yet, but I have another ATMega on the way to experiment with.

I think its advantages of the EZM Studios variants  are that it is relatively close to stock hardware and software, with the hidden modes already enabled, has a socketed MCU, and most of the components are through-hole for easier tweaking. I think the main downside is that the SMD contact pattern isn't great, and some people have suggested replacing the caps.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on February 04, 2015, 03:48:32 am
@eas

It seems that you have the same board as mine.
In this case, you can compile the  setting of the Makefile  that is described  in my previous posts
http://www.eevblog.com/forum/testgear/ (http://www.eevblog.com/forum/testgear/)$20-lcr-esr-transistor-checker-project/799/
http://www.eevblog.com/forum/testgear/ (http://www.eevblog.com/forum/testgear/)$20-lcr-esr-transistor-checker-project/800/
http://www.eevblog.com/forum/testgear/ (http://www.eevblog.com/forum/testgear/)$20-lcr-esr-transistor-checker-project/801/

and in mojoe  post to get the screen right
http://www.eevblog.com/forum/testgear/ (http://www.eevblog.com/forum/testgear/)$20-lcr-esr-transistor-checker-project/804/

In summary   :

In the makefile,

comment the two line s
#CFLAGS += -DLCD_ST7565_H_FLIP=1
#CFLAGS += -DLCD_ST7565_V_FLIP=1

The font is better with
CFLAGS += -DFONT_6X8

Correct the contrast with
LCD_ST7565_RESISTOR_RATIO = 5
instead of
LCD_ST7565_RESISTOR_RATIO = 4

and  To get the double-spaced lines,  in the file lcd-routines.c:

Change:
lcd_set_cursor(1,0)
lcd_set_cursor(2,0)
lcd_set_cursor(3,0)

To:
lcd_set_cursor(2,0);
lcd_set_cursor(4,0);
lcd_set_cursor(6,0)

Jacques
Title: Re: $20 LCR ESR Transistor checker project
Post by: eas on February 04, 2015, 06:47:49 am
@eas

It seems that you have the same board as mine.
[...]

Yes, thanks! I've already made note of all those posts, but it will be very helpful for others. 

Someone contacted me privately asking about how the GM328 compared to other versions I tried. I'm part way through editing a video and blog post on just that topic, but I thought I'd add a little more here:

That meter is my favorite of the three I've tried. In casual inspection, it seems to correctly identify every component I've tried, where as the others I tried have had trouble with some depending on the orientation.

I also tried the largest screen Fish8840 version, and this 91Make version (http://www.ebay.com/itm/261457669748?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT). In retrospect, the largest screen is pointless, in my opinion, and the graphics for components are too "heavy," which makes them hard to make sense of, a problem for the diagrams of simple BJTs and even more so small signal MOSFET.

I like the graphics/ui on the 91Make version best of all, but the firmware seems somewhat dated, doesn't have the full feature set enabled, and the hardware isn't hack friendly -- all surface mount, and to make use of, what I assume are the holes for the programming header, will require either pogopins, or detaching the LCD mounted directly to the PCB.

I plan to compile the latest open source firmware and install it on the Fish8840 tester, taking advantage of what Moejoe learned.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on February 04, 2015, 09:33:01 am
I also tried the largest screen Fish8840 version, and this 91Make version (http://www.ebay.com/itm/261457669748?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT). In retrospect, the largest screen is pointless, in my opinion, and the graphics for components are too "heavy," which makes them hard to make sense of, a problem for the diagrams of simple BJTs and even more so small signal MOSFET.
The firmware that you compile will have considerably "lighter" graphics. As for the value of the graphical screen, there are at least two advantages: You can choose any size font (try CFLAGS += -DFONT_8X16 if you need glasses to read the screen), and you can use any character set, which becomes a huge issue with text displays that have no international characters (I want to give one of these as a gift to someone who speaks no English and would have to bend over backwards to get a 16x2 display that supports the characters from the right alphabet).
Title: Re: $20 LCR ESR Transistor checker project
Post by: coromonadalix on February 17, 2015, 10:33:57 am
noob questions

Under Windows 8.1 x64     how can i compile the makefile,  i know nothing about this ???  what softwares do i have to install, WinAvr ? AvrDude ? Atmel studio ?

i have a atmega8 based tester, the first post image model ...   (avr rc crystal), updated to an mega328 model with 16x2 lcd  with the 1.11k trunk / mega328 section   works ok

i have read a lot of this thread  ... 

Wanted to use the 1.16m version, (since its supposed to be text only version),  but it stalls when displaying  zenner voltage / something ??? display show 16.5 volts, the button powers up the tester,  but it doesn't shutdown unless i remove the 9v cell


Found this : http://www.avrtester.tode.cz/index.php?p=firmware (http://www.avrtester.tode.cz/index.php?p=firmware)    already compiled hex and eep files   may help you guys
Title: Re: $20 LCR ESR Transistor checker project
Post by: samnmax on February 17, 2015, 10:21:58 pm
Just a warning for anyone buying one of those chinese clones, the one that says "MTester V2.07" "By Efan &HaoQixin". I bought one from ebay for 15€, and it didn't work very well, it was slow and crashed with some components. Poking around with the scope I found that the crystal oscillator was not used!  :o

I soldered the ISP pins and connected to the Bus Pirate, avrdude said ATmega328P low fuse was 0x62 (default value). That means: "use internal RC oscillator" and "divide clock by 8"  :palm:

I tried to change the fuse but it was locked. I had to extract a copy of the flash and eeprom, erase the chip, set the fuse (I think I used 0xF7) and upload eeprom and flash again.

Afterwards, it worked fine! Somebody must have forgotten to program the fuse. Other than that I think it's very useful for its price.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 18, 2015, 12:24:49 am
Under Windows 8.1 x64     how can i compile the makefile,  i know nothing about this ???  what softwares do i have to install, WinAvr ? AvrDude ? Atmel studio ?
The Makefile is used by the 'make' tool to build the firmware, it's some kind of special script. Atmel Studio supports external Makefiles (see GCC Project options and configuration tab).

Wanted to use the 1.16m version, (since its supposed to be text only version),  but it stalls when displaying  zenner voltage / something ??? display show 16.5 volts, the button powers up the tester,  but it doesn't shutdown unless i remove the 9v cell
To exit the m-firmware's zener tool please push the test button twice (two short presses). There's a readme file in the source package explaining the differences to the k-firmware including the UI.

BTW: 1.17m was realeased two days ago (several minor improvements and fixes).
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on February 18, 2015, 12:16:12 pm
[...]I had to extract a copy of the flash and eeprom[...]

Would you mind sharing them? I'd like to try this firmware on my EZMStudio device. Really wish they'd publish the sources.
Title: Re: $20 LCR ESR Transistor checker project
Post by: samnmax on February 19, 2015, 06:10:12 am
[...]I had to extract a copy of the flash and eeprom[...]

Would you mind sharing them? I'd like to try this firmware on my EZMStudio device. Really wish they'd publish the sources.

No problem, here they are.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on February 20, 2015, 04:04:54 am
Much appreciated, thank you. From the looks of it, I am not the only one interested in them. I did a quick test and the firmware seems to work (shuts down the tester because the voltage is too low), but I get nothing on the screen, so it will need some modifications  :-/O, which, unfortunately, I won't be able to get started on for at least a month. If I manage to get this firmware to work on my tester, I will post the changed files.
Title: Re: $20 LCR ESR Transistor checker project
Post by: gtroc71 on February 24, 2015, 06:47:09 am
Could this device be run from an A23 12v battery?
Would like to make as compact as possible
Thanks
Title: Re: $20 LCR ESR Transistor checker project
Post by: JacquesBBB on February 24, 2015, 07:05:43 am
Could this device be run from an A23 12v battery?

As there is a 5V linear regulator on these boards (AS1117 5.0 V on mine), it will not be very efficient
to power it with 12V. Everything above 7V is wasted.
9V is much more adapted.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 24, 2015, 07:11:00 am
Could this device be run from an A23 12v battery?
Would like to make as compact as possible

I think so, but that battery won't last long (about 1/10 of a 9V one). And you should disable the LCD backlight.
Title: Re: $20 LCR ESR Transistor checker project
Post by: gtroc71 on February 24, 2015, 01:02:39 pm
Thank you so much Jacques and Madires.
Appreciate your fast response
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 24, 2015, 11:23:33 pm
Wow,
Looks like I have been slacking here. And a lot of catching up to do. Had forgotten all about this thread.
I have 2 of these now but one is dead. Maybe I will have a go at learning to update the firmware in mine and repairing the dead one.
So much to go back and read |O
I did not even know about the self calibrate lol.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 26, 2015, 02:57:37 am
This was my first one I purchased.  And my first fail  |O
While testing some 100uf caps at 350 volts one of the caps did not get enough discharge time. When I connected the test leads the tester failed to come on. At least this is what I think happened.

(http://gokarters.com/smf/index.php?action=dlattach;topic=2454.0;attach=1541;image)

In the pic you can see a programmer I purchased a few months back and have yet to use it.
So I think my first attempt is to grab the schematic of this tester and install a header on the board.
I will attempt to communicate with the processor.

Been a long time (1990) since I have even attempted to read and program Atmel chips.  And even then it was a complete different beast back then.
At least this may give me a chance to learn a few things.

(http://gokarters.com/smf/index.php?action=dlattach;topic=2454.0;attach=1543;image)


As said in my above post I have a lot of catching up to do. And a lot of back reading. If anyone would like to give some pointers I am all ears :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 26, 2015, 05:23:56 am
Well perhaps I was wrong about the controller being dead. After installing the pin header I was able to read the contents from the Atmega 168 chip.

After doing this I noticed something that was not happening before.  When ever I connected the battery to the device and hit the test button nothing happened. No display no red LED.
But now when I hit the test button for a couple of seconds I get a message on the LCD.

"BAT 4.8V empty"

I know my battery is good and test at 9 volts. So I but my DMM across the battery leads and when you hit the test button the voltage drops from 9 to 4 volts.

Looks like I need to check some on board components and see if any are failing.

(http://gokarters.com/smf/index.php?action=dlattach;topic=2454.0;attach=1545;image)

Perhaps I should had started another thread instead of tying this one up.


Edit to say, looks like I can read the chip but when I programmed the chip I just get a black bar now when I press the test button.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on February 26, 2015, 09:42:25 pm
I did a quick test and the firmware seems to work (shuts down the tester because the voltage is too low), but I get nothing on the screen, so it will need some modifications  :-/O, which, unfortunately, I won't be able to get started on for at least a month. If I manage to get this firmware to work on my tester, I will post the changed files.

Looks like I won't be doing that after all. Had a little time on my hands and tried it out. The firmware is for strip-grid layout, which is not a problem, but the way it displays information seemed to look good from the screenshots, but up close and personal, I didn't like it at all. So I see no reason to try hacking it. On the other hand, I like the fact that they tried to use the screen in a more logical way for a graphical LCD. Something to think about when I actually get to do some coding.

Markus, Karl-Heinz, neither of you answered previously. If I make changes, is there a way to submit them to you without the use of SVN?

Edit to say, looks like I can read the chip but when I programmed the chip I just get a black bar now when I press the test button.

Does it turn off as soon as the button is released?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 26, 2015, 10:00:42 pm
Markus, Karl-Heinz, neither of you answered previously. If I make changes, is there a way to submit them to you without the use of SVN?

Send them directly to Karl-Heinz via email ;)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 26, 2015, 11:03:54 pm


Does it turn off as soon as the button is released?
Yes, The string of bars are only present while holding the test button.
As said before this is my first attempt at programming so this is a new learniing curve for me. I am using Extreme AVR burner and dont think I am doing it right. I read something in the "testers" manual about having to set fuse bytes. So with that I am sure I am doing something wrong.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on February 27, 2015, 11:51:09 am
Send them directly to Karl-Heinz via email ;)

Will do, thanks!

Yes, The string of bars are only present while holding the test button.
As said before this is my first attempt at programming so this is a new learniing curve for me. I am using Extreme AVR burner and dont think I am doing it right. I read something in the "testers" manual about having to set fuse bytes. So with that I am sure I am doing something wrong.

You need to burn both flash and EEPROM for the tester to work. Looks like flash didn't get programmed that time. I wouldn't recommend messing with fuse bits until you figure out what most of them do.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 27, 2015, 12:18:43 pm

You need to burn both flash and EEPROM for the tester to work. Looks like flash didn't get programmed that time.

I really think you are correct. Although the program says it is doing both somehow I do not think it is.

Quote
I wouldn't recommend messing with fuse bits until you figure out what most of them do.
Agreed and I have not touched those settings yet.

Back in the early 90's is the last time I have even played with any Atmels. And even then it was just a flash. So I am a complete noob when it comes to them. Since this tester is dead I thought perhaps this would be a good learning tool on the programming and learn a bit on how these testers work.  Even if I brick the chip I have the equipment and the knowledge to replace them.

I did notice something about the tester. The dead one has a 8MHz crystal on board and the new one has no crystal.  Both testers are identical other than the missing crystal.

Overthe next few days as time allows I plan to do a bit of reading up on AVR programming and watch a few YT vids.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 28, 2015, 12:19:46 am
Quote
I wouldn't recommend messing with fuse bits until you figure out what most of them do.
Agreed and I have not touched those settings yet.
You need to set the fuse bits only once for a brand new ATmega. The Makefile includes the logic to select the correct fuse settings and to call avrdude. For the k-firmware you simply call 'make fuses', 'make fuses-crystal' or 'make fuses-crystal-lp' based on the clock source. For the m-firmware it's just a 'make fuses'.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 28, 2015, 05:57:25 am

You need to set the fuse bits only once for a brand new ATmega. The Makefile includes the logic to select the correct fuse settings and to call avrdude. For the k-firmware you simply call 'make fuses', 'make fuses-crystal' or 'make fuses-crystal-lp' based on the clock source. For the m-firmware it's just a 'make fuses'.

Thanks for that bit of info madires.
Have not used avrdude yet. The only program I have tried is Extreme AVR. If I remember correctly I think avrdude is a dos base program. Atleast that is what I remember from Youtube.
I will try and do some more reading and YT vids over the short week end.
Title: Re: $20 LCR ESR Transistor checker project
Post by: dadler on February 28, 2015, 06:06:31 am
I got one of these boxes off ebay, but the cheap 2mm banana jacks drove me nuts. So I swapped in some shrouded 4mm jacks to be able to use my Fluke leads:

(https://dl.dropboxusercontent.com/s/mbps3ujuh50e5kz/mk-168_37.jpg)
(https://dl.dropboxusercontent.com/s/pxzez43m2bgt59j/mk-168_35.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on February 28, 2015, 07:54:40 am
I have the same unit, where did you find the shrouded connectors?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on February 28, 2015, 09:38:04 am
Thats looks pretty nice.
Thinking about ordering another one of these. Maybe that one.

Anyway been serching for more info on programing.  Read till my head hurts.
Sure wish there were some yourtube videos on this tester and programming it.  :-//
Know more about how would be nice, like do you program flash first or hex?  Have not been able to find this info. But I am sure I will  ;D
Title: Re: $20 LCR ESR Transistor checker project
Post by: dadler on February 28, 2015, 09:48:37 am
I have the same unit, where did you find the shrouded connectors?

I got them at the corner electronics store. They are just standard Pomona shrouded jacks. I can get the part number if you want.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on February 28, 2015, 10:22:55 pm

Anyway been serching for more info on programing.  Read till my head hurts.
Sure wish there were some yourtube videos on this tester and programming it.  :-//
Know more about how would be nice, like do you program flash fist or hex?  Have not been able to find this info. But I am sure I will  ;D

It's programmed like any other ATmega via ISP. A quick search for "flashing atmega" at youtube lists a lot of videos. If you got an avrdude compatible ISP programmer and the make tool, a "make upload" will do the job.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 10, 2015, 02:53:43 pm
If anyone has the latest m328p hex file for the M168 version (2x16 LCD) I'd appreciate it if you could attach a copy here.

edit: I found this, which contains a hex file. Is it the correct one?
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 10, 2015, 11:26:42 pm
If anyone has the latest m328p hex file for the M168 version (2x16 LCD) I'd appreciate it if you could attach a copy here.

edit: I found this, which contains a hex file. Is it the correct one?
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/)

If your tester has an ATmega168, please compile the firmware for the ATmega168. The pre-compiled ATmega328 firmware is too large for the ATmega168 (16kB flash). The ATmega328 got 32kB flash.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 11, 2015, 12:45:06 am
It's got a 328p.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 11, 2015, 01:40:50 am
It's got a 328p.

Ok, then it's the correct firmware. If you read the Makefile you'll see the enabled features.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 11, 2015, 04:56:51 am
Will the hex file set the config fuses correctly? I'm also using an Arduino in arduinoisp mode to program a blank ATmega328p, any hint using avrdude would be appreciated.

I'm a PIC programmer, AVR's are alien to me.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 11, 2015, 06:53:42 am
Will the hex file set the config fuses correctly? I'm also using an Arduino in arduinoisp mode to program a blank ATmega328p, any hint using avrdude would be appreciated.

No, the hex doesn't include fuse settings. But you could use avrdude to set the fuses if required (actually just for a brand new ATmega). If the ATmega already runs a tester firmware you don't need to re-write the fuses.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 11, 2015, 07:40:12 am
I ran the make file, it created a hex file. The fuse settings are still 00 00 00 so they're not getting set. I'm also not able to program the eeprom.
Quote
avrdude -c arduino -p m328p -P /dev/cu.usbmodem1411 -U flash:w:TransistorTester.hex:a -U eeprom:w:TransistorTester.eep:a

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e950f
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "TransistorTester.hex"
avrdude: input file TransistorTester.hex auto detected as Intel Hex
avrdude: writing flash (23832 bytes):

Writing | ################################################## | 100% 3.83s

avrdude: 23832 bytes of flash written
avrdude: verifying flash memory against TransistorTester.hex:
avrdude: load data flash data from input file TransistorTester.hex:
avrdude: input file TransistorTester.hex auto detected as Intel Hex
avrdude: input file TransistorTester.hex contains 23832 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 3.06s

avrdude: verifying ...
avrdude: 23832 bytes of flash verified
avrdude: reading input file "TransistorTester.eep"
avrdude: input file TransistorTester.eep auto detected as Intel Hex
avrdude: writing eeprom (14 bytes):

Writing | ################################################## | 100% 0.06s

avrdude: 14 bytes of eeprom written
avrdude: verifying eeprom memory against TransistorTester.eep:
avrdude: load data eeprom data from input file TransistorTester.eep:
avrdude: input file TransistorTester.eep auto detected as Intel Hex
avrdude: input file TransistorTester.eep contains 14 bytes
avrdude: reading on-chip eeprom data:

Reading | ################################################## | 100% 0.03s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
         0xff != 0x14
avrdude: verification error; content mismatch

avrdude: safemode: Fuses OK (H:00, E:00, L:00)

avrdude done.  Thank you.

Here's the TransistorTester I'm using.
(http://image4.pushauction.com/0/0/24b1a674-60a7-4d1b-80d4-58f42c015155/0f9bb578-8822-d4ce-7faf-de3d9eac290d.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 11, 2015, 08:40:16 pm
I ran the make file, it created a hex file. The fuse settings are still 00 00 00 so they're not getting set. I'm also not able to program the eeprom.

Didn't you use the pre-compiled firmware? Anyway, a few posts ago I explained how to use the Makefile to set the fuses. But since you've got an error while verifying the EEPROM, there's another issue.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimmc on March 11, 2015, 10:35:03 pm
I've got the same (Banggood) version, the original fuse settings were...
L   0xFF
H   0xD9
E   0x04
LB   0x3F

I enabled  the brownout detection using...
(I know that there have been problems reported when using brownout detection but if the power glitches I'd prefer to know and fix it - No problems so far.)
L   0xFF
H   0xD9
E   0x07
LB   0x3C

I used the precompiled .hex & .eep files.

Jim
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 12, 2015, 12:20:49 am
I've got the same (Banggood) version, the original fuse settings were...
L   0xFF
H   0xD9
E   0x04
LB   0x3F

I enabled  the brownout detection using...
(I know that there have been problems reported when using brownout detection but if the power glitches I'd prefer to know and fix it - No problems so far.)
L   0xFF
H   0xD9
E   0x07
LB   0x3C

I used the precompiled .hex & .eep files.

Jim

What version did you find? 1.17m?

Would you mind attaching the .hex & .eep files here?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 12, 2015, 04:36:33 am
Would you mind attaching the .hex & .eep files here?

There's a nice site (http://www.avrtester.tode.cz/index.php?p=firmware (http://www.avrtester.tode.cz/index.php?p=firmware)) with firmware files for most versions.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 12, 2015, 01:04:52 pm
Thanks, I tried FW1.11M328 but it displays rubbish after the power on screen? Could this be because of incorrect fuse settings? Seems the Flash and eprom program fine.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 12, 2015, 10:48:54 pm
Thanks, I tried FW1.11M328 but it displays rubbish after the power on screen? Could this be because of incorrect fuse settings? Seems the Flash and eprom program fine.

It's possible. The fuses set the clock source (internal RC, external quartz or external resonator) and the clock prescaler. I assume the firmware is compiled for an external quartz and 8MHz.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 01:56:45 am
Thanks, I tried FW1.11M328 but it displays rubbish after the power on screen? Could this be because of incorrect fuse settings? Seems the Flash and eprom program fine.

Flashed a firmware with a language that your display does not support?
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 02:34:58 am
Thanks, I tried FW1.11M328 but it displays rubbish after the power on screen? Could this be because of incorrect fuse settings? Seems the Flash and eprom program fine.

Flashed a firmware with a language that your display does not support?

Possibly, I used the EN folder, but it does say testing... on the powerup screen. Now I've got to build an HV programmer to reset the fuses! puddles of fun.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 03:11:16 am
Why would you want to do that? Simply try flashing a different firmware.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 03:14:28 am
Why would you want to do that? Simply try flashing a different firmware.

I've flashed pretty much any firmware I could find including the eeprom. Some power up with a bat & test screen but subsequent screens are garbage text. This is on a new ATMega328p, I didn't refresh the original with 1.05.

If anyone has an eep & hex combo (upload here) that works on a banggood board I'd be happy to try it.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 03:36:04 am
I'd like to suggest two things. First, if you don't have much money to put into a decent AVR ISP programmer, just get the cheapest one from eBay. There is no need for HV to program fuses unless your chip refuses to be programmed via ISP, and it beats trying to get Arduino to do something that it doesn't like doing. Second, "garbage text" doesn't tell much. Images could help a bit in such cases.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 04:48:04 am
I'd like to suggest two things. First, if you don't have much money to put into a decent AVR ISP programmer, just get the cheapest one from eBay. There is no need for HV to program fuses unless your chip refuses to be programmed via ISP, and it beats trying to get Arduino to do something that it doesn't like doing. Second, "garbage text" doesn't tell much. Images could help a bit in such cases.

I'm a PIC programmer with PIC tools, if this was a PIC based project I'd have it working by now. I've even considered porting it!

Here's the rub, there are several modifications to the original design, crystal, LCD- GLCD display, voltage reference, HV zener, rotary encoder, Mega8, 168, 328... the list goes on. This makes it a little daunting to anyone unfamiliar with AVR programming. Worse yet are 99% of the programmers for ATMEL are the LV serial variety, so if you mess up the fuse settings well that's that. I've messed up a couple of 328p when trying to set the fuses. This command -U efuse:w:0xfc:m would set the lfuse to 0x04 go figure.

I think the Arduino is a nifty bit of kit, simple IDE to setup & install, cross platform, and a no brainer workflow. On the other hand I have no real interest or use for ATMEL micro controllers or wish to blow $85 CDn on an AVR Dragon for what will amount to a one off endeavour. I simply want to upgrade a banggood clone to 1.11k or possible 1.17m (is one better than the other?). I'm using a bit pirate as a programmer. I might pick up a USBTiny programmer as they're supposed to work with OS X.

Seems I'm not the only person that had problems upgrading the firmware on an MK168. Based on this thread alone looks like most folks don't get it working without some help.

I've tried the files in the UK & EN directories (EN english? UK english? err what) FW 1.11K latest from this site. http://www.avrtester.tode.cz/index.php?p=firmware (http://www.avrtester.tode.cz/index.php?p=firmware) But without knowing what options were chosen it makes it tough to know if it'll work.
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 06:13:08 am
Here's the rub, there are several modifications to the original design, crystal, LCD- GLCD display, voltage reference, HV zener, rotary encoder, Mega8, 168, 328... the list goes on. This makes it a little daunting to anyone unfamiliar with AVR programming.

Not sure I understand how one follows from the other. The software options need to match your hardware, but that's how it would have been with any microcontroller. So, you simply use, for example the st7565 firmware if you have an st7565-based screen. Pretty straightforward in most cases.

I simply want to upgrade a banggood clone to 1.11k or possible 1.17m (is one better than the other?).

They are a little different, but it's best to try both first-hand to see which one you like better.

Seems I'm not the only person that had problems upgrading the firmware on an MK168. Based on this thread alone looks like most folks don't get it working without some help.

Which I find very strange. They seem to be just a rather vanilla implementation of the circuit, so the firmware from mikrocontroller.net, whether m or k, should just work if the flash and EEPROM are programmed correctly. Hopefully, you're not flashing M168 firmware into your 328p?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 13, 2015, 08:10:15 am
I've flashed pretty much any firmware I could find including the eeprom. Some power up with a bat & test screen but subsequent screens are garbage text. This is on a new ATMega328p, I didn't refresh the original with 1.05.

For a brand new ATmega you have to set the fuses, since the default setting is to use the internal RC as clock source and the 1:8 prescaler, resulting in an 1MHz MCU clock.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 08:20:27 am
I've flashed pretty much any firmware I could find including the eeprom. Some power up with a bat & test screen but subsequent screens are garbage text. This is on a new ATMega328p, I didn't refresh the original with 1.05.

For a brand new ATmega you have to set the fuses, since the default setting is to use the internal RC as clock source and the 1:8 prescaler, resulting in an 1MHz MCU clock.

Wouldn't the LCD work normally though?
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 08:35:04 am
Yes. Just slower.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 08:46:19 am
What's the difference between the EN & UK versions? Spelling?
Title: Re: $20 LCR ESR Transistor checker project
Post by: hapless on March 13, 2015, 09:00:55 am
EN is supposed to be English. UK... I have no clue. Ukrainian? I doubt that it stands for United Kingdom.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 10:26:33 am
Well I'll be, I was using the wrong UK firmware. 1.11K flashed no problem, thank you.

I'll still have to get the fuses working but that can wait, I'll flash the original chip tonight.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 13, 2015, 04:44:04 pm
I've flashed pretty much any firmware I could find including the eeprom. Some power up with a bat & test screen but subsequent screens are garbage text. This is on a new ATMega328p, I didn't refresh the original with 1.05.

For a brand new ATmega you have to set the fuses, since the default setting is to use the internal RC as clock source and the 1:8 prescaler, resulting in an 1MHz MCU clock.

I got it working, it's an excellent bit of kit and I'm gobsmacked that you're the Markus that designed the thing :-+

My noob level AVR experience got me into trouble as I had to get the hang of avrdude plus a bus pirate pressed into service as a programmer and sort out which firmware worked with the banggook kit.

Did I mention it's a great addition to the handy as anything tool collection.
(http://www.electro-tech-online.com/imgcache/4956-JunebugMongoose.jpg)
FYI: a few years back I designed the Junebug kit, a PICkit2 programmer tutor, so I'm not completely...
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 13, 2015, 10:19:10 pm
I got it working, it's an excellent bit of kit and I'm gobsmacked that you're the Markus that designed the thing :-+

Great! And nope, I'm the Markus who does the m-firmware. The Markus who did the original design abandoned the project. Karl-Keinz (k-firmware) took over and I joined in.
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimmc on March 14, 2015, 12:40:56 am
Glad you got it working, I had used 1.11k from http://www.mikrocontroller.net/svnbrowser/transistortester/#dirlist (http://www.mikrocontroller.net/svnbrowser/transistortester/#dirlist) but I couldn't find the revision I had used (360?).

I believe there is now a version 1.12k (latest is always under 'trunk') but I haven't tried it yet.

Jim
Title: Re: $20 LCR ESR Transistor checker project
Post by: Radio Tech on March 14, 2015, 01:10:06 am
Nice going.
As far as my project I have given up on it  for the moment.
Just do not know much about AVR programming and got to see if I can find a better noob training video.
I do know I was not sending anything to my chip.  Read somewhere on this thread about the file size was too large. So that is most  likely my problem.
So think mine in blank and giving me just a bar when the test button is pressed.

Not sure if I even have the correct programmer
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 14, 2015, 03:39:53 am
Nice going.
As far as my project I have given up on it  for the moment.
Just do not know much about AVR programming and got to see if I can find a better noob training video.
I do know I was not sending anything to my chip.  Read somewhere on this thread about the file size was too large. So that is most  likely my problem.
So think mine in blank and giving me just a bar when the test button is pressed.

Not sure if I even have the correct programmer

It looks like a USBTiny. If it's not a 328p get a 328p before you begin.
Assuming you're using an ATMega328p, from your command prompt try.
 avrdude -c usbtiny -p m328p
Title: Re: $20 LCR ESR Transistor checker project
Post by: jimmc on March 14, 2015, 06:31:23 am
Nice going.
As far as my project I have given up on it  for the moment.
Just do not know much about AVR programming and got to see if I can find a better noob training video.
I do know I was not sending anything to my chip.  Read somewhere on this thread about the file size was too large. So that is most  likely my problem.
So think mine in blank and giving me just a bar when the test button is pressed.

Not sure if I even have the correct programmer

I'm an AVR newbie too, I found that AVRDudess (http://blog.zakkemble.co.uk/avrdudess-a-gui-for-avrdude/ (http://blog.zakkemble.co.uk/avrdudess-a-gui-for-avrdude/)) GUI for AVRDude made my life much easier.
I did have problems installing LibUSB until I used Zadig (http://zadig.akeo.ie/ (http://zadig.akeo.ie/)) which sorted the installation for me. (Windows 8.1)

Jim
Title: Re: $20 LCR ESR Transistor checker project
Post by: coromonadalix on March 14, 2015, 07:45:24 am
With windows 8.1  for me    the usbtiny v3 dongle works best, it has the 6 and 10 pins connectors, avrdude and avrdudess are great.

Had many troubles with Atmel products ( i have avr dragon, isp mkII, stk500  etc ...)  passed windows 8,  the damned drivers signatures ....  are a pain.

Be careful,  flashing some mega 328 with no crystal  may give errors ... depending of the programmed fuses,    learned the hard way.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 16, 2015, 04:29:41 am
I got it working, it's an excellent bit of kit and I'm gobsmacked that you're the Markus that designed the thing :-+

Great! And nope, I'm the Markus who does the m-firmware. The Markus who did the original design abandoned the project. Karl-Keinz (k-firmware) took over and I joined in.

Do you have any documentation on your version of the firmware? Is it an enhanced K firmware or something alltogether different?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 16, 2015, 09:58:24 pm
Great! And nope, I'm the Markus who does the m-firmware. The Markus who did the original design abandoned the project. Karl-Keinz (k-firmware) took over and I joined in.

Do you have any documentation on your version of the firmware? Is it an enhanced K firmware or something alltogether different?

The distribution package includes a readme file describing all the differences. The functionality of both firmwares is quite similar. but there are differences on how things are done. And the m-firmware lacks support of graphical LCDs (might change). The m-firmware measures caps down to 5pF for example, or is able to distinguish MT1 and MT2 of a detected TRIAC.
Title: Re: $20 LCR ESR Transistor checker project
Post by: texaspyro on March 17, 2015, 05:07:21 am

And the m-firmware lacks support of graphical LCDs (might change). The m-firmware measures caps down to 5pF for example, or is able to distinguish MT1 and MT2 of a detected TRIAC.

Well, if you find yourself with a little time on your hands,  how about adding the graphics support (with pretty device pictures),   the ability to measure FET on resistance,  and a scope/logic analyzer mode?  I'd buy you a beer...
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 25, 2015, 05:53:23 am
Great! And nope, I'm the Markus who does the m-firmware. The Markus who did the original design abandoned the project. Karl-Keinz (k-firmware) took over and I joined in.

Do you have any documentation on your version of the firmware? Is it an enhanced K firmware or something alltogether different?

The distribution package includes a readme file describing all the differences. The functionality of both firmwares is quite similar. but there are differences on how things are done. And the m-firmware lacks support of graphical LCDs (might change). The m-firmware measures caps down to 5pF for example, or is able to distinguish MT1 and MT2 of a detected TRIAC.

I'm going to give your firmware a try, mind posting a link to the distribution package? The sites I've found are all in German.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 25, 2015, 06:11:19 am
I'm going to give your firmware a try, mind posting a link to the distribution package? The sites I've found are all in German.

You'll find the source at http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/ (http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/) or pre-compiled versions at http://www.avrtester.tode.cz/index.php?p=firmware (http://www.avrtester.tode.cz/index.php?p=firmware) for example.
Title: Re: $20 LCR ESR Transistor checker project
Post by: BlueBill on March 27, 2015, 01:02:09 am
I've tried 1.17m

It seems somewhat different, it seems to be in continuous auto test mode and it doesn't begin a calibrate when I connect all three leads on power up. Also I haven't found any other test modes (holding down the switch on the k firmware). Does it need the rotary switch?
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on March 27, 2015, 04:29:41 am
I've tried 1.17m

It seems somewhat different, it seems to be in continuous auto test mode and it doesn't begin a calibrate when I connect all three leads on power up. Also I haven't found any other test modes (holding down the switch on the k firmware). Does it need the rotary switch?

Please read the README file in the distribution archive. Everything is explained there. Power on the tester with a long key press (>0.3s) for the auto-hold mode. For the menu short circuit all three probes or press the test button two times (short key presses). And it doesn't require a rotary encoder, besides for the squarewave generator.
Title: Re: $20 LCR ESR Transistor checker project
Post by: sasa_mm on March 27, 2015, 11:23:24 am
Hello
I bought on ebay this esr meter
(http://lygte-info.dk/pic/ComponentTesters/Fish8840V2.1/DSC_7173.jpg)

everything is working ok except for the measurement of capacity and ESR
If I measuring small value capacitors <10uF readings are quite accurate but when I measure 100uF results are about 200uF (5 capatitors new and used) esr 0.20-0.40ohm
for 1000uF readings are 600-700uF,
470uF readings 0nF vloss around 1% esr no readings
1500, 2200uF readings 0nF

for all test I used brand new and used capatitators
Can someone help me to fix it? I try calibrate (connect pins 1 2 3 go trough test mode....)
thank you
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on March 28, 2015, 11:19:16 pm
Most probably is the wrong setting of fuses. The correct values should be:
lfuse:0xff hfuse:0xd9 efuse:0x04

In the annex is backup original firmware of my tester (v2.1) and compiled firmware v1.12k revision 424 (Karl-Heinz Kübbeler).

Note
The problem could be a bad value C16. The correct value must be 1nF.
Title: Re: $20 LCR ESR Transistor checker project
Post by: sasa_mm on March 30, 2015, 02:18:52 am
thanks for your response
I measured the c16 and its value is 1nF.
I'm new at this, to do new firmware I need USBASP interface?
like this
http://www.ebay.com/itm/USBASP-USBISP-AVR-Programmer-Adapter-10-Pin-Cable-USB-ATMEGA8-ATMEGA128-Arduino-/310506909410?pt=LH_DefaultDomain_0&hash=item484ba76ee2 (http://www.ebay.com/itm/USBASP-USBISP-AVR-Programmer-Adapter-10-Pin-Cable-USB-ATMEGA8-ATMEGA128-Arduino-/310506909410?pt=LH_DefaultDomain_0&hash=item484ba76ee2)
on ebay I can find that can flash ATmega328P or this one can?
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on March 30, 2015, 07:05:19 pm
Yes. I use exactly this type of USBasp programmers. In practice, you can use any ISP programmer intended for programming AVR MCU's.

The attached picture documents connection USBasp to board of my tester with the ISP connector.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Muxr on April 02, 2015, 02:13:38 am
I got one of these for $15 off Ebay. So far it's been doing the right thing on any component I tried. I am actually kind of impressed.
Title: Re: $20 LCR ESR Transistor checker project
Post by: JoeO on April 02, 2015, 07:35:26 am
How about a link to the seller's page.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Muxr on April 02, 2015, 03:52:37 pm
How about a link to the seller's page.
here you go: http://www.ebay.com/itm/281476169022?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT (http://www.ebay.com/itm/281476169022?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on April 03, 2015, 10:37:53 pm
Freshly compiled and tested version 1.12k revision 444 for Fish8840 Tester. To download at the end of the first post on the forum:
AVR Component Tester (RLC/ESR & Semiconductors Tester) (http://svetelektro.com/Forum/avr-component-tester-rlc-esr-semiconductors-tester-t30285.html)
or here  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: neslekkim on April 04, 2015, 02:51:40 am
Which of the testers are that?, I found another one described here:
http://techobsessed.net/2015/01/fish8840-avr-transistor-tester-review/ (http://techobsessed.net/2015/01/fish8840-avr-transistor-tester-review/)

Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on April 04, 2015, 04:13:54 am
My tester I bought here:
Ebay item: 281477820303 (http://www.ebay.com/itm/281477820303)

It is precisely this:
Review: Component Tester Fish8840 (http://lygte-info.dk/review/ComponentTester%20Fish8840%20UK.html)

Note:
These devices are sold by many vendors with different display panel. However, the motherboard is identical - see attached pictures.
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on April 04, 2015, 04:42:55 am
"Fish8840 Tester" version I preferred due to the easy implementation of other types of LCD (characters or graphics). Supplementing of few parts (LCD & ISP connector, trimer 10k) and changing one resistor on mainboard LCD (LED resistor) can be used classic 16x2 character LCD. Further adjustments can be with supplemented precision voltage source (R19, U3) and fix the connection of the voltage divider (R8, R15) for battery voltage measurement. A lot of useful information can be found in the official manual (http://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/?view=tar) (by Karl-Heinz Kübbeler).
Title: Re: $20 LCR ESR Transistor checker project
Post by: eas on April 04, 2015, 08:03:49 pm
My tester I bought here:
Ebay item: 281477820303 (http://www.ebay.com/itm/281477820303)

It is precisely this:
Review: Component Tester Fish8840 (http://lygte-info.dk/review/ComponentTester%20Fish8840%20UK.html)

Note:
These devices are sold by many vendors with different display panel. However, the motherboard is identical - see attached pictures.

I'm pretty sure all of those originated from Fish8840's TaoBao store.

The yellow "T-4" transistor tester Muxr linked to comes from 91Make's TaoBao, which is also the source of the inexpensive AD584 voltage reference boards, and the slightly more expensive plexi-encased versions that have been mentioned elsewhere on the forum before.

I like the presentation of the information on the 91Make version the best, but I like the "EZM Electronics Studio" GM328 (http://www.ebay.com/itm/GM328-transistor-tester-ESR-table-LCR-frequency-meter-square-wave-genera/171467739124) most because it is, as I understand it, closest to the original design, and open source firmware, plus the MCU is socketed and most of the components are through-hole for easier modification. There are variants with both a graphical display and a 2-line display.

I should probably finish the video I started editing comparing the three...but I probably won't.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gyro on April 05, 2015, 12:46:10 am
I've owned two of these testers now. The first was a Fish8840, which I stupidly killed with a (not very) charged capacitor. My current one is a "Yellow T-4", I got the up-market one with the plexiglass case, but the board looks identical to the cheap ones. I could never think of an easy way of casing the Fish8840 due to the separate display board needing either a stepped front panel or extending the ZIF socket and buttons.

A couple of observations. I agree that the Yellow "T-4" screen layout does seem to be the easiest to read (aging eyes) it also has an external 2.5V reference on board, even if it is only a TL431 rather than anything more exotic, I couldn't find one on the Fish8840 PCB. The battery voltage reading on the T-4 seems to start low on the "T-4" and slowly creep up over subsequent presses of the test button, no idea why that would be. The "T-4" has a slightly amusing representation of a Zener when connected between pins 1 and 3... It shows it as two opposite polarity diodes in SERIES rather than parallel.

The first thing I did after buying the second tester was to fit the relay input protection mod as detailed in the official manual. I hadn't realised just how sensitive the inputs would be to a capacitor that had been unsoldered and sitting for several days (charge recovery).
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on April 05, 2015, 02:31:56 am
@Gyro:
I sent a personal message.
Title: Re: $20 LCR ESR Transistor checker project
Post by: intrax on April 12, 2015, 01:14:25 am
What about this one:

http://m.ebay.com/itm/251791049879?nav=SEARCH (http://m.ebay.com/itm/251791049879?nav=SEARCH)

Power through rechargable batt. or usb and suitable for in circuit testing…

Any comments?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Towger on April 12, 2015, 01:52:21 am
I am still waiting for the Free Electron version...
Title: Re: $20 LCR ESR Transistor checker project
Post by: tom666 on April 12, 2015, 01:58:29 am
What about this one:
http://m.ebay.com/itm/251791049879?nav=SEARCH (http://m.ebay.com/itm/251791049879?nav=SEARCH)
Power through rechargable batt. or usb and suitable for in circuit testing…
Any comments?
All of this testers are just only different variations of the PCB - based on the standard wiring diagram (http://www.mikrocontroller.net/articles/Datei:TransistorTesterVC1.png) ;) This tester includes rechargeable battery - it is only one difference.  Images on ebay documented use of the original software by Karl-Heinz Kübbeler. In recent posts on the official discussion forum (http://www.mikrocontroller.net/topic/248078?page=7#4086662) you will find also some information.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Yekuku on April 17, 2015, 09:16:13 am
I got this one :  LCR-T5 Mega328 (http://www.banggood.com/LCR-T5-Mega328-Transistor-Tester-Diode-Triode-Capacitance-ESR-Meter-p-945644.html) but I am having some issues...
(http://img.banggood.com/images/2014/xiemeijuan/09/SKU162928/SKU162928-1.jpg)
Unit seems to operate well but when testing electrolytic capacitors the screen flickers and gets upside down and mirrored.
Could it be a buggy factory firmware or a component issue? Did anybody else had the same problem?

Title: Re: $20 LCR ESR Transistor checker project
Post by: Richard Crowley on April 17, 2015, 02:57:47 pm
Are you careful to fully discharge large capacitors before trying to test them?
Title: Re: $20 LCR ESR Transistor checker project
Post by: Yekuku on April 17, 2015, 07:06:54 pm
Are you careful to fully discharge large capacitors before trying to test them?
Yes, all caps are properly discharged.
It looks to me like  a firmware / LCD screen compatibility issue. Any suggestions ?
The screen looks like this :
(http://i177.photobucket.com/albums/w211/yekuku/30f79999-6111-4a69-8e27-b3db3f8c31aa_zpswbwrajfm.jpg)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gyro on April 18, 2015, 08:07:10 pm
I'd suggest beefing up the supply decoupling as these boards seem to have minimal amounts, try a 10uF on the regulator output as a starting point and additional 100n's as close as you reasonably can to the chip.
Title: Re: $20 LCR ESR Transistor checker project
Post by: aRGee on April 19, 2015, 05:46:42 am
Hi to all ! did anybody of you try to add a Rotary encoder to one of the chinese clones with a graphical display ? I tried a Rotary switch with my homemade tester with M-firmware and a 2*16 line display , it worked fine. When I tried the chinese clone with graphic display (the one from EZM electronics and discrete components) I didn't succeed, I tried a lot of combinations of PD1,PD2 and PD3 inputs of the atmega328.  Maybe somebody has an idea ?? Robert.

ps : I changed the 680R/470K resistors for the 0.1% types and also replaced the voltage regulator for a mcp1702-5002 and I got an accuracy of 0.1% back when measuring a precision resistor
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gixy on April 20, 2015, 12:08:48 am
Hello,
I bought this one on eBay. The software version is 1.11. I've got the documentation on the website of the developpers but I don't find what exactly are the information displayed for transistors: what are IC0 and ICs?
Thanks
Denis
Title: Re: $20 LCR ESR Transistor checker project
Post by: bianchifan on April 21, 2015, 06:45:42 am
Quote from: tom666
In the annex is backup original firmware of my tester (v2.1)
Thank you very mch! How did you get it?

What about this one:
http://m.ebay.com/itm/251791049879?nav=SEARCH (http://m.ebay.com/itm/251791049879?nav=SEARCH)
Any comments?
Feel free for a little look inside here:
http://www.mikrocontroller.net/topic/248078?page=7#4086662 (http://www.mikrocontroller.net/topic/248078?page=7#4086662)
FW from 15.04.2015:
http://www.mikrocontroller.net/topic/248078?page=7#4092967 (http://www.mikrocontroller.net/topic/248078?page=7#4092967)

Quote from: aRGee
When I tried the chinese clone with graphic display (the one from EZM electronics and discrete components) I didn't succeed, I tried a lot of combinations of PD1,PD2 and PD3 inputs of the atmega328.
I do not know EZM, only Fish and new LiIon, but the rotary must be activated in the makefile.
IMHO you need a special compiled version of your own, no standard-hex.
In some makefiles the rotary is pre activated.

Quote from: aRGee
I changed the 680R/470K resistors for the 0.1% types and also replaced the voltage regulator for a mcp1702-5002 and I got an accuracy of 0.1% back when measuring a precision resistor
.1% resistors are no bad idea but the LDO alone isn't the hack... you need to offer an external voltage reference.
My choose was a LT1009C, it's precision is 0.2%. So the overall prec should be better than 0.5%.
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on April 21, 2015, 01:41:15 pm
Hello,
I bought this one on eBay. The software version is 1.11. I've got the documentation on the website of the developpers but I don't find what exactly are the information displayed for transistors: what are IC0 and ICs?
Thanks
Denis

Vf forward
Vt threshold
S source
D drain
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gixy on April 21, 2015, 03:44:59 pm
Thanks Shock,
With BJT transistors the device indicates ICE0 and ICEs (forgot the ´E' in my previous post). Those values are most of the time 0.00mA with small signls transistors, and non zero for power transistors.  Probably collector-emitter currents, but in which conditions? There are also the current gain hFE and a voltage Uf (base-emitter).
For MOS and FET, the device indicates only two voltages: Vt and Uf and a capacity.
The user manual explains very well the measurement principles, but not the results.
Denis
Title: Re: $20 LCR ESR Transistor checker project
Post by: Shock on April 21, 2015, 05:43:56 pm
Gixy you can find all the acronyms with diagrams here
http://www.onsemi.com/pub_link/Collateral/AN1628-D.PDF (http://www.onsemi.com/pub_link/Collateral/AN1628-D.PDF)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Gixy on April 21, 2015, 07:54:30 pm
Excellent document Shock, I appreciate.
ICEo (not ICE0) and ICEs are then leakage currents under reverse voltages. I found also this document from the device's developpers.
This device is really impressive!
Denis

Title: Re: $20 LCR ESR Transistor checker project
Post by: Gyro on April 21, 2015, 08:42:08 pm
Quote
.1% resistors are no bad idea but the LDO alone isn't the hack... you need to offer an external voltage reference.
My choose was a LT1009C, it's precision is 0.2%. So the overall prec should be better than 0.5%.

Having said that, it's worth just checking the accuracy of the cheapo TL431 reference on the board (if fitted) before swapping it - the one on mine reads a nice stable 2.501V  :)
Title: Re: $20 LCR ESR Transistor checker project
Post by: Evil Lurker on April 23, 2015, 10:15:26 am
I'm debating on getting one of the Chinese "GM328 fish clone" testers.

Anyone know where I could land an unpopulated PCB so that I can use my own precision components?



Title: Re: $20 LCR ESR Transistor checker project
Post by: firepower on April 23, 2015, 02:54:05 pm
Still be more economical to buy one and remove parts you dont want.
Title: Re: $20 LCR ESR Transistor checker project
Post by: madires on April 23, 2015, 10:21:10 pm
Anyone know where I could land an unpopulated PCB so that I can use my own precision components?

There are several PCB layouts in the forum at http://www.mikrocontroller.net/topic/248078 (http://www.mikrocontroller.net/topic/248078) (mostly German) and from time to time someone organizes an aggregated order. But I haven't seen any shop selling bare PCBs yet. You can also find two PCBs in the firmware repo for DYI-ing (one is veroboard based, and the other one is for through-hole parts). There's also an rotary encoder / frequency counter adapter for character LCDs.
Title: Re: $20 LCR ESR Transistor checker project
Post by: mikronauts on April 25, 2015, 12:54:51 pm