$20 LCR ESR Transistor checker project

[stj]

latest is 1.12k SVN r684
and it does NOT support multi-coloured display output.

so you should try to dump the atmel in that unit.

[Dwaine]

latest is 1.12k SVN r684
and it does NOT support multi-coloured display output.

so you should try to dump the atmel in that unit.

I'll try it and see if I can get a dump

[kodi]

fixed.
 

I assume this banggood kit source is referring to this:
http://www.banggood.com/DIY-M12864-Graphics-Version-Transistor-Tester-Kit-LCR-ESR-PWM-With-Case-p-997023.html ?

[stj]

yes,
i didnt test it though - i did personally test the other 2, but i obviously arent about to collect lots of testers. 

[Dwaine]

latest is 1.12k SVN r684
and it does NOT support multi-coloured display output.

so you should try to dump the atmel in that unit.

Well I got two hours out of it.   Measured a capacitor and now it won't power up.   That was quick.  I think it's even a record for myself.

[flywheelz]

Now that more people got the color TFT units and had some time to play with them, how do they compare to the previous models?

From window shopping, what stands out in the new color TFT models to me is the nicer looking screens.  The input protections, DC jack and the extra connectors.  The DC voltage measurement and up to 30v zeners.

But...

• Is the slow display a real issue?
• Are you missing features due to Memory limitation?
• Are improvements worth extra price?
• Delay in software updates or none?

Is there one kit that is considered the "best"?  Its going to be my first.

[Willem52]

Not all the newer testers have all the options.

So do not all have the input protection circuit, that is for me a must have.

I have The EZM GM328A and the "Mega328 Color-Kit" models.
Both do a good job.

[stj]

• Is the slow display a real issue?

if it's your first - you wont really know any better,
if not then it will piss you off pretty fast.
it may be fixed by upgrading the clock from 8 to 16MHz with a new crystal - i will report on that when i get some more crystals.

• Are you missing features due to Memory limitation?

yes, at the moment you cant enable the crystal / resonator test.
(that test only works if you upgrade the crystal to 16MHz anyway)

• Delay in software updates or none?

software updates come from people like me and other forum members.

[flywheelz]

ok guys I ordered the TFT version.  http://www.aliexpress.com/item/2016-DIY-kits-TFT-LCD-M328-Transistor-Tester-LCR-Diode-Capacitance-ESR-voltage-meter-PWM-Square/32649811953.html

 Mainly because of having DC jack and whatever protection its got.

stj, thank you for baking the various firmwares. 

[tom666]

...

• Delay in software updates or none?

...

I recommend to carefully study the manual (file ttester.pdf) from the official SVN repository. Here you can also download the current k-variant of software by Karl-Heinz Kübbeler (kubi48) and alternative m-variant of software by Markus Reschke (madires).

For your tester with TFT color display is designed k-firmware in the folder "mega328_color_kit". Content of this folder (files TransistorTester.hex and TransistorTester.eep) can be used directly for burning to the MCU. If you require any changes to the firmware settings, you can make before compiling the adjustments in the file "Makefile". Of course a lot of useful information can be found in the above-mentioned manuals.

Note
In theory it could work also with m-firmware (by madires) because this software also supports controller ST7735.

[flywheelz]

tom,

Is there a comparison somewhere between k and m variant?  Perhaps I should have made my purchase with software in mind.

I take it if a variant supports my display in source code which you noted I have "ST7735" display, then I can compile it for my display?

[stj]

you can use both versions on any modern hardware.

modern as in using a cpu with atleast 32k flash.
no old ATMEGA8 / 168 hardware

[flywheelz]

you can use both versions on any modern hardware.

modern as in using a cpu with atleast 32k flash.
no old ATMEGA8 / 168 hardware

and no multi-colored units?

[stj]

K & M both handle tft colour displays.

[hapless]

I have a question about the VCC measured during self-adjustment of the m version. I measured it as 5.024V with a nicely adjusted DMM and set that in the config file. After the adjustment procedure, it gets set to 5.038V. Where should I look to correct this (i.e, I want the self-adjustment to measure correctly rather than just setting this manually)?

[deanflyer]

I need a cheap ESR tester to test a load of capacitors on a faulty power supply board. This looks like a good option.

There are loads of these chinese units out there. Not bothered about programming (maybe later, just dont have the time at present).

This unit seems okay as its got banana plugs and the zif board you can plug in.

Any comments, or any other units I should be looking at?

eBay auction: #http://www.ebay.co.uk/itm/Portable-MK-328-Transistor-Tester-Diode-Capacitance-LCR-ESR-Meter-PNP-NPN-O04F-/361444775198?hash=item5427c9951e

[madires]

I have a question about the VCC measured during self-adjustment of the m version. I measured it as 5.024V with a nicely adjusted DMM and set that in the config file. After the adjustment procedure, it gets set to 5.038V. Where should I look to correct this (i.e, I want the self-adjustment to measure correctly rather than just setting this manually)?

If you have enabled the external 2.5V reference in config.h, then the value set via UREF_VCC in config.h is adjusted accordingly to the external reference. In this case, measure also the voltage of the 2.5V reference and change UREF_25 in config.h too. Or disable the external reference to prevent the automatic adjustment of UREF_VCC. You might also need to tweak the values a little bit to reach your desired voltage, because the ATmega328 has a resolution of only 4.88mV with Vcc (5V) as reference. Another setting to play
with is ADC_SAMPLES. More samples will improve the measurement, but slow it down at the same time.

[flywheelz]

I need a cheap ESR tester to test a load of capacitors on a faulty power supply board. This looks like a good option.

There are loads of these chinese units out there. Not bothered about programming (maybe later, just dont have the time at present).

This unit seems okay as its got banana plugs and the zif board you can plug in.

Any comments, or any other units I should be looking at?
http://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=mk-328&_sacat=0

I think this MK-328 is one of the best units I've seen for everyday bench use.  Mega328p chip, three clip leads and nice case with brass inserts.  Looks like it even has input protection.  If you had posted a day sooner I would have bought this one for sure instead of the 328-color tft kit.  A member indman has a folder for mk-328 with teardown pics and few older firmwares https://yadi.sk/d/yW8xa5NJgUo5z

All the best.

[deanflyer]

Cheers Flywheelz,

Unit ordered

[hapless]

If you have enabled the external 2.5V reference in config.h, then the value set via UREF_VCC in config.h is adjusted accordingly to the external reference. In this case, measure also the voltage of the 2.5V reference and change UREF_25 in config.h too. Or disable the external reference to prevent the automatic adjustment of UREF_VCC. You might also need to tweak the values a little bit to reach your desired voltage, because the ATmega328 has a resolution of only 4.88mV with Vcc (5V) as reference. Another setting to play with is ADC_SAMPLES. More samples will improve the measurement, but slow it down at the same time.

That's what puzzles me. I set the voltage of the reference after measuring it, too, so I see no reason for the small but persistent offset. I could adjust it to compensate, of course, but that would be cheating.  I tried different numbers of samples, but the default seems good enough. Anything else I could try? By the way, the bandgap offset voltage is also set high, 15mV up from my measured 5mV... possibly related?

[madires]

Seems so. Have you measured Vcc at the AVCC pin of the ATmega?

[hapless]

It's connected directly to VCC. Did you mean AREF? Right now I'm getting 1077mV both with my DMM and with the self-adjustment measurement.

[Harm2k16]

Hi all,
I'amfollowing this topic for quite a while now, but i can't seem to find a solution for my MTester (LCR-T4 NoStripGrid, ATMega328P, 8MHz, FPC-12864B graphical display).
When i bought the unit, the display was buggy. So ordered a new one on eBay and replaced the 328P chip.
...but then what i tried, i can't seem to flash (read: get hold of) the appropriate software or software wich works with this tester.
The only thing i've found is (compiled) firmware on this site:

https://yadi.sk/d/yW8xa5NJgUo5z

...but this 8MHz firmware is in the Russian language, don't misunderstand me, i don't have anything against Russian, but i can't simple read it and don't understand it either.
No i have a question for you gentlemen/ladies; does anyone have ready compiled firmware for my/this tester in the English language?

(For clarity, on yadi.sk it's the LCR-T4(T3)NoStripGrid tester with a 8 MHz crystal and no rotary encoder, just a push-button switch.)

Please seeking help with this.
Thank you in advance.

(P.S. I use the "Extreme Burner AVR" from this site: http://extremeelectronics.co.in/avr-tutorials/gui-software-for-usbasp-based-usb-avr-programmers/ in combination with a USBASP hardware from LC-Studio (eBay)).

[hapless]

Could you be more specific about the firmware you tried to use other than the Russian one, and exactly how it didn't work (upside-down screen? immediate shutdown?)?

[stj]

The only thing i've found is (compiled) firmware on this site:

https://yadi.sk/d/yW8xa5NJgUo5z

...but this 8MHz firmware is in the Russian language, don't misunderstand me, i don't have anything against Russian, but i can't simple read it and don't understand it either.

they included the makefile - give me 5 min's