$20 LCR ESR Transistor checker project

[madires]

I see that the PCB already contains a Zener test. Is there a list and circuits for other options?

Please see the documentation of both OSHW firmwares (k and m) and also the hardware directory in the repo.

Also, instead of the near-obsolete 9V batteries, I would prefer to use 5V power and/or Li-Ion batteries with boost-up to 5V, which would also simplify some of the circuitry. (Possibly even using a cheap Chinese boost-up for the Zener part) Is there a reason to use 9V?

No, you just need a stable, clean and precise 5V supply. And don't forget to adapt the power management  to whatever you choose. The tester shown by Obelix2007 comes with a LiPo battery plus boost converter and linear post regulation, for example.

[steveharriss]

Really appreciate that. Here's the manufactured PCB's. I have a few spares I can send out for postage. I'm in the UK

[Aldo22]

I can confirm that these come with an ATMEGA328PU (Version "English Language" without "New").
Not particularly fast, but much more accurate than my TC1 with the APT32F172K8T6.

[madires]

That's an AY-AT (aka GM328A) which is still a nice basic tester. And it's supported by both OSHW firmwares (k & m).

[morgan_flint]

I can confirm that these come with an ATMEGA328PU (Version "English Language" without "New").
Not particularly fast, but much more accurate than my TC1 with the APT32F172K8T6.

And the "New English Version" of that seller also comes with a genuine ATMEGA328PU, as I confirmed here , just in QFP package.

[Aldo22]

That's an AY-AT (aka GM328A) which is still a nice basic tester.

Yes, I've done a few simple tests.
It's pretty accurate for such a cheap device.
Attached:
200Ω (1%) SMD resistor.
1KHz
1.0111 V

[mentholflash]

Really appreciate that. Here's the manufactured PCB's. I have a few spares I can send out for postage. I'm in the UK

Hey mate whereabouts in the uk are you would you consider sending 1 to Australia
cheers

[mentholflash]

Hi all
Can anyone tell me if this is
A. OK
2. Going to work
for adding a rotary encoder to 2013 booster edition
Thanks

[hojnikb]

Is anyone still porting LGT8F328P to m/k-firmware ?

Or is this it? https://github.com/DurandA/transistor-tester-lgt328p

[dirtmover]

I recently bought a TC2 HaoQi from AliExpress and the PCB was silkscreened with "T7-PLUS V2.0". The tester is utter crap as the measurements are very inconsistent, erroneous and all over the place 

I fell for that POS as well and am having similar problems. There's some instructions a few months back for swapping out the LGT8F328P for an Atmega328 and switching to open source FW to get it working correctly.

https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4804496/#msg4804496
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4899587/#msg4899587

I've got a couple of Atmega328p in my parts drawer so will give this a try when I get a chance.

Is anyone still porting LGT8F328P to m/k-firmware ?

Or is this it? https://github.com/DurandA/transistor-tester-lgt328p

That repo looks abandoned since Feb 2021. I think you can safely say that was a pie in the sky attempt that never got off the ground.

[madires]

Is anyone still porting LGT8F328P to m/k-firmware ?

Someone wanted to, but I don't know the current status.

[madires]

Can anyone tell me if this is
A. OK
2. Going to work
for adding a rotary encoder to 2013 booster edition

The resistors seem to be reversed. Please see Karl-Heinz' documentation (https://github.com/kubi48/TransistorTester-documentation) for the rotary encoder option.

[DELTA67]

Hi all,
Thanks madires for maintaining this awesome project!!!
How about using an LGT8F328P instead of the ATMEGA328P?
Can the 12bit resolution of the ADC in the LGT improve accuracy?
Is the differential mode, of the said ADC, of any useful application in measurements?
How about the pseudo math coprocessor uDSC, Can it speed some calculations?

[madires]

We'll stick with the ATmega for the next years for several reasons. e.g. long term availability. If someone likes to port the OSHW firmwares to the LGT8F328P that would be totally fine with us. I have no hands-on experience with the LGT8F328P, so I can't say anything about the impact of its higher resolution ADC. The circuit of the Transistortester is designed for single-ended inputs. Complex real-time calculations aren't done by the firmware to keep the firmware size small. Instead we use tables with pre-calculated values.for those cases.

[DELTA67]

OK, GREAT thanks anyway.
I want to try using an external ADC (ADS1115) instead of the integrated one. is it mandatory to read many samples then averaging and How to calculate values like "BJT_Level = 2557; " to accommodate the new 15bit resolution ?
Can you, please, add a battery testing function (Li-ion and Lead-acid types) ?
Perhaps this needs extra hardware to measure cranking current for LA batteries for example.

[madires]

The oversampling with the ATmega's internal ADC is done to improve the resolution, accuracy and measurement results. Moving to an external ADC won't be easy as you would need to adapt large parts of the firmware. If you want to do that the first step is to understand the firmware. Only then you will be able to determine what you have to change and how. And it will surely increase the firmware size significantly. For battery testing I'd recommend a proper battery tester, expecially for batteries with a high short circuit current. Yes, that involves power electronics, e.g. a bank of MOSFETs to switch the current.

[coromonadalix]

@delta67

since all the code is / are available  you are free to implement what you want and share your results

this project is made simple to avoid the previously given explanations, adding this or that will change the code and design, and the project price

you are free to adapt whatever mcu you want etc ...   you have more powerful arduino pcb's  teensy's   stm32 arduino compatible stufff you can go up to 24 bits  if you want  loll  any lcd size too

i have one of theses   it work well enough for  my needs

but keep in mind  this is not a professional tool  in any way,  its not a dmm
not a battery load, not a professional  lcr   etc ...

it is a general / simple tool / practical tool 

[DELTA67]

@coromonadalix
I know very well this great project and I'm aware of it's limitations. I've built one not just bought a ready made clone.

@ Markus
I've tested (PROTEUS simulation) the ADS1115 with a stripped down version of Frejek's code and it works "pas mal"!
The problem is with the voltage values. For an 1N4148 I've got more than 1V forward voltage.
I've joined the code with simulation file.
NOTE:
- This stripped version can be used as a starting point to study the full code.
- ADS1115 module is very easy to use (code) and to add to the hardware.
- The full code has already the I2C driver needed to communicate with the ADS.

[ayubando]

Wow. I would surely  loveto have one

[madires]

Something for long, cold winter evenings:

v1.51m
- Changed GetThirdProbe() into convenience function UpdateProbes2() to reduce firmware size and adapted calls in various other functions (suggested by Viktor Klimkovich).
- Optimized DataStorage() and ManageAdjustmentStorage() to reduce firmware size (thanks to Viktor Klimkovich).
- Added option to slow down bit-bang SPI in case of a high MCU clock rate (SPI_SLOWDOWN, suggested by Viktor Klimkovich).
- Changed calculation of delay loop in IR_Detector() to support MCU overclocking (thanks to Viktor Klimkovich).
- Improved voltage drop algorithm in function LargeCap().
- Function LargeCap() takes now also negative zero offset into account.
- Changed self-adjustment to show the list of adjustment values only on success to prevent any misunderstanding.
- Corrected wrong value in E24 table (reported by siealex@EEVblog).
- POWER_OFF_TIMEOUT applies also to the main menu now (suggested by indman@EEVblog).
- Added French texts (thanks to moimem@EEVblog).
- Updated Brazilian Portuguese texts (thanks to wandows@EEVblog).
- Updated Polish texts #2 (thanks to Jacon@EEVblog).
- Corrected character 'q' in font_8x8_iso8859-2_hf.h (thanks to siealex@EEVblog).
- Updated Russian texts (thanks to indman@EEVblog).
- Updated Spanish texts (thanks to pepe10000@EEVblog).

Please downlaod at:
- https://github.com/madires/Transistortester-Warehouse/tree/master/Firmware/m-firmware
- https://github.com/kubi48/TransistorTester-source/tree/master/Markus

[moimem]

Thanks madires for the update, here attached my 1.51m builds for LCR-T4 nostripgrid

[Brad808]

This thread is great, thanks for all the information and hard work! I spent last weekend replacing the ATmega328p in a bside esr02 (blew it up with a charged cap a long time ago) and programming 1.13k onto it. I have a second esr02 that I bought after the first one blew up and I'm thinking of trying to put the m firmware on that one. Does anyone release a pre-compiled version of the m firmware for the esr02? I did find an old version floating around, but I wasn't sure if anyone maintains new versions anywhere. Thanks

[horo]

If you want to experiment you can also clone my repo that's a mirror of Markus' source code in git mode.

https://github.com/Ho-Ro/ComponentTester

Here's the branch of my version for the AY-AT with 20 MHz:

https://github.com/Ho-Ro/ComponentTester/tree/AY-AT_20MHz

[Yuriy_K]

Something for long, cold winter evenings:
v1.51m

Thank you madires.

There were problems during testing.
With these settings

//#define SW_MONITOR_L          /* just L */
#define SW_MONITOR_RCL        /* R plus L, or C plus ESR */
//#define SW_MONITOR_RL         /* R plus L */

Capacitors are measured unstably at inputs 1-2, 2-3 and are not measured at inputs 1-3.
Hiland M644 16 MHz.
shown in the photo:

[madires]

I tried your settings with a 16MHz ATmega644 tester but couldn't reproduce what you've seen. Also after running the RCL monitor a 1µF cap measured fine for all probe combinations.