$20 LCR ESR Transistor checker project

[papabol_24]

Thanks tom it works now, one question pls? why is that when i compile fw using the make file that u give i always get a bigger hex file?

[tom666]

This is a problem of the older version of the compiler.

It was discussed several times here:
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg747575/#msg747575

[papabol_24]

Oh ok thanks again tom, 

[Radio Tech]

So decided to get back on this one tonight. Got some software loaded on a win 7 machine and read the mcu. Got a read. Was doing a few things and picked the tester up. The MCU was very hot. Guess this confirms that it is bad.     Now to order some, and do a swap.

[AlxDroidDev]

So decided to get back on this one tonight. Got some software loaded on a win 7 machine and read the mcu. Got a read. Was doing a few things and picked the tester up. The MCU was very hot. Guess this confirms that it is bad.     Now to order some, and do a swap.

If you wee able to read something from it (for example, its fuses, using avrdude) after it cooled down, it's probably not damaged (yet). These Atmegas can take a lot of beating.

Check for any short-circuit that might be causing its pins to source more than 40mA. If that's what's happening, any other MCU you replace that with, will also be damaged.

[Radio Tech]

If you wee able to read something from it (for example, its fuses, using avrdude) after it cooled down, it's probably not damaged (yet). These Atmegas can take a lot of beating.

Check for any short-circuit that might be causing its pins to source more than 40mA. If that's what's happening, any other MCU you replace that with, will also be damaged.

I had it under the scope earlier, no short circuit found. Not to say that there may not be  a component elsewhere that is shorted. Like I have said in a previous post I think a high voltage cap I tested may had been the culprit that caused the unit to fail.

Now as far as the read I got. Using Extreme burner.
This is my  second attempt ever with a programmer to read/write to a atmel chip. So I have know idea what I am seeing.
I did verify that it was actually doing something by clicking read with and without the header plugged in. Without being plugged in I got fails. With plugged in I got success.

[Gyro]

These things are REALLY easy to blow up when testing a capacitor, particularly a HV one that you think is discharged but has recovered some charge - go on, ask me how I know 

The symptoms when I did it were MCU getting hot and a tendency to identify everything as a mosfet! It still drove the display fine, presumably one or more MCU input protection diodes had fused.

When I replaced it, the first thing I did was to implement input protection - I used the relay option that shorts all the inputs together while not actively testing (as documented in the ttester.pdf for the 'k' version software). In my view this is a 'must have' modification.

[madires]

This is my  second attempt ever with a programmer to read/write to a atmel chip. So I have know idea what I am seeing.
I did verify that it was actually doing something by clicking read with and without the header plugged in. Without being plugged in I got fails. With plugged in I got success.

If the read was successful you should be able to find a lot of known strings.

[madires]

When I replaced it, the first thing I did was to implement input protection - I used the relay option that shorts all the inputs together while not actively testing (as documented in the ttester.pdf for the 'k' version software). In my view this is a 'must have' modification.

Another solution is to add a SRV05?4. The m-firmware supports the protection relay also (HW_RELAY in config,h).

[Gyro]

The m-firmware supports the protection relay also (HW_RELAY in config,h)

My apologies madires, I am only familiar with the other version.

[timofonic]

These things are REALLY easy to blow up when testing a capacitor, particularly a HV one that you think is discharged but has recovered some charge - go on, ask me how I know 

The symptoms when I did it were MCU getting hot and a tendency to identify everything as a mosfet! It still drove the display fine, presumably one or more MCU input protection diodes had fused.

When I replaced it, the first thing I did was to implement input protection - I used the relay option that shorts all the inputs together while not actively testing (as documented in the ttester.pdf for the 'k' version software). In my view this is a 'must have' modification.

I would love to have the best design done in KiCad, with the latest hardware and all kind of recommendations+additions. It could be the "trendy" hardware branch

I'll look about it if nobody does it earlier and I that happens quite common, I'm slow like a turtle. This will be my first "complex" project in my vocational school.

It ca  be an interesting way to convince my teacher to be the rebel guy that uses KiCad instead OrCAD 9.2. Yes, THAT old and only ONE fscking UNDO LEVEL! Even old KiCad from 2013 is less messy than this.

[Macbeth]

OrCAD 9.2? There's a blast from the past. It can do one thing I've not seen other software do - auto routing single sided boards with jumper links.

[timofonic]

OrCAD 9.2? There's a blast from the past. It can do one thing I've not seen other software do - auto routing single sided boards with jumper links.

OFFTOPIC WARNING
It's slightly less cumbersome to use than KiCad in the behavior of the wires, the rest is worse. It's full of windows too.

It has built-in simulation. I don't care about that so much, I hope to not get mad with SPICE model assignation when using KiCad.

Anyway, my computer isn't fast enough to run the EDA apps fluidly.
I need to be the classroom rebel and fight alone, there's no escape: No money for a faster computer, mine's an old workstation that was fast when bought but not anymore. Bloatware and lack of money sucks. I tried to "sin" by installing Windows, but there were severe issues that made impossible to finish the process.

Today I tried to run Circuit Wizard 1.5 on a local Internet cafe with Windows 10 and it worked worse than in Wine. I'm amazed!
END OF OFFTOPIC

I plan to try to replicate the best design under KiCad and publish it in GitHub, of course!

[gojimmypi]

This is one great thread.

I am reading through everything (from page 1) and deciding if I order one ($23 on DX, but will end up costing $55 due to taxes) or build my own. I haven't read everything yet, but has anyone here had success with a homemade tester?

yes! complete success!

fwiw - I ordered mine here:

http://www.ebay.com/itm/381351024208

and it was only 4.99 shipping to USA (and apparently also to Brazil?)

(thanks again to whoever it was that recommend that link to me on this forum!)

In addition to all the nice detailed photos there, don't miss the "installation instructions" link:

https://www.dropbox.com/sh/uo7nr7xet09esbu/AAAMAjU0sE2hFqCXe0VAsGM_a?dl=0

but in case the link stops working, I've attached the file. There's definitely useful information there. (oops, the file is 3.5MB, and we can only upload 1MB here)

It was cool that the M328 also came pre-programmed. Assembly was really rather easy, and the device seems to work quite well. It is very cool.  Bravo!

I'm looking forward to digging into the source code.

http://www.mikrocontroller.net/svnbrowser/transistortester/

https://github.com/svn2github/transistortester

Enjoy!

[Datman]

Hi all
I've received yesterday my GM328A V1.20 2015.05 EZM Electronics studio
http://www.ebay.com/itm/New-All-in-1-Component-Tester-Transistor-Diode-Capacitance-ESR-Meter-Inductance-/321511426333?

Do you think I have any chance of mounting a indented rotary encoder instead of the pushbutton?
Does anyone know where can I find the original source code and, if needed for the encoder, an appropriate code?

Thanks!
Gianluca

[con-f-use]

Bottom-line, yes you can, but you will need to adjust the firmware. You will find documentation, links to the different firmwares and a schematic of the base unit linked in this thread.

[tom666]

I've received yesterday my GM328A V1.20 2015.05 EZM Electronics studio

Do you think I have any chance of mounting a indented rotary encoder instead of the pushbutton?
Does anyone know where can I find the original source code and, if needed for the encoder, an appropriate code?

Here you will find the answer (read also the following posts):
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg690137/#msg690137

[Datman]

Uhmm... After a few posts, discussion has gone to batteries... :-(

[tom666]

OK, so once again :
1. Is necessary to connect the encoder to MCU ports PD1 and PD3 as recommended.
2. Edit the file "Makefile" (CFLAGS += -DWITH_ROTARY_SWITCH=2 - enable encoder) and make compilation. This refers to the folder mega328_GM328.
3. Then this modified firmware flash to the MCU

That is all

[con-f-use]

That is all

You forgot:

[4] Pray, you got the other Makefile options right for your specific tester (graphic display, resistor-devider-ratio, etc.).

[MLXXXp]

Do you think I have any chance of mounting a indented rotary encoder instead of the pushbutton?

I have one with a 16 x 2 display but the way I added a rotary encoder may be of some use to you.
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg777509/#msg777509

[tom666]

You forgot:

[4] Pray, you got the other Makefile options right for your specific tester (graphic display, resistor-devider-ratio, etc.).

I did not forget

Folder mega328_GM328 contains the firmware designed directly for his GM328 tester. It need only set control with the rotary encoder.

[gojimmypi]

my transistor checker project kit arrived from China a couple of weeks ago. assembly went very smoothly and it works!  now my extra ATMEGA328P chips have arrived, so I was about to download the source code to start playing, when ta-da! I realized there's no JTAG, ISP, or any other pins available on the board for doing any sort of in-place, on-chip debugging. 

does anyone have a suggestion of how I might be able to compile & step through code with the '328 in place? I have both a bus pirate and AVR programmer on hand & hoping not to have to order an expensive emulator. can GDB / OpenOCD be used for this? I've not been able to find any information on how how this might be wired up.

thanks

[Messtechniker]

https://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/

Download the complete tarball. Look for the PDF file it contains (ttester.pdf).
Find the solution in the circuit diagram on page 10.

Yours - Messtechniker

[gojimmypi]

https://www.mikrocontroller.net/svnbrowser/transistortester/Doku/trunk/pdftex/english/

Download the complete tarball. Look for the PDF file it contains (ttester.pdf).
Find the solution in the circuit diagram on page 10.

Yours - Messtechniker

aha! an ISP header in next version! most excellent. thanks for the tip. I was just poking though the '328 data sheet to see if those pins were directly exposed. now to solder one onto my board. I appreciate your response!