$20 LCR ESR Transistor checker project

[madires]

Have you tried the settings for AY-AT / GM328A in the Clones file? And don't forget to program also the EEPROM.

[wandows]

Yes, I've tried several versions and the only one that works is version 1.12.

And I always update the EEPROM

[indman]

After updating the firmware I'm having some problems, could any friends help me solve this problem (M328_KIT_TFT)?
Note: The device works normally with the original firmware

You have combined the files from the modified firmware with the original files yourself and compiling? Therefore, the display is chaos.
In order for the modified firmware to work well, you need to make changes in a very large number of source files and understand the whole mechanism of the author's algorithm. 

[wandows]

I modified the following files:
makefile
config.h
config_328.

[indman]

In that case you need to clean the entire crystal before you update the firmware. I see in the screenshot you showed the remnants of code from the previous firmware.

[wandows]

Friend indmam, what would be the procedure to clean the crystal?

[indman]

wandows,I don't know what shell you use. For example, in a very simple program AVRDUDE PROG 3.3 cleaning of the entire crystal is done by simply pressing the button which I have shown with a red arrow.

[Yuriy_K]

A small addition to the TTester circuit allows you to measure the frequencies of quartz and ceramic resonators. This is for testers that have an input for measuring frequency. The picture shows unsuccessful measurements of the Ttester according to the HilandM644 scheme, the first three pictures are the top row and measurements according to the attached scheme. For example, various measurements are given. The measurement range of the above circuit is 32 kHz - 4.5 MHz.
If you need to measure quartz resonators at high frequencies, use the 74HC4060, change the resistors and capacitors down and use a prescaler.

[wandows]

wandows,I don't know what shell you use. For example, in a very simple program AVRDUDE PROG 3.3 cleaning of the entire crystal is done by simply pressing the button which I have shown with a red arrow.

Hello friend indman!

I managed to solve it, and the problem was in the selection of the .HEX and .EEP files.

By a simple oversight I was selecting the .HEX file for the EEPROM.

Update completed successfully!

Thanks in advance for your attention and help!!!

[Martini]

I'd like to buy my first (and hopefully last) component tester. Could you advise me the right hardware and firmware depending on my requirements?

Please see https://github.com/madires/Transistortester-Warehouse/blob/master/Documentation/English/Clone-Comparison-Chart.pdf for an overview.

I did check it out but I'm not sure that's enough for me to make a decision

• I'll use it mostly for in-circuit capacitor testing, is there any difference ESR-wise?
• I saw the m firmware could test capacitor leakage (like this?). How does it work, what hardwares can do it?
• Does the power supply make any difference? Like, will a tester using a 9V battery be able to generate a 9V signal from his function generator? Or test a higher voltage Zener diode?
• I think a rotary encoder makes them easier to use, so that limits the choice
• I also think I'd like the pads to test DPAK or SOT-223 components

[madires]

I'll use it mostly for in-circuit capacitor testing, is there any difference ESR-wise?

No, but I'd recommend a dedicated in-circuit ESR tester (lower test voltage)

saw the m firmware could test capacitor leakage (like this?). How does it work, what hardwares can do it?

Works with standard probes, but only up to 5V. If you are playing with higher voltages better get a special leakage tester which can provide the voltages the DUTs are rated for.

Does the power supply make any difference? Like, will a tester using a 9V battery be able to generate a 9V signal from his function generator? Or test a higher voltage Zener diode?

Just 5V signals. However, the Zener check uses a separate boost converter up to 50V output. Some clones generate a test voltage around 25 or 35V, a few about 45V.

[juvann]

Very big and interesting thread, sorry if I don't read all pages, I tried to search my question without success.
I'd like buy a LCR-T7(2) and use the good alternative firmware madires, but I'd like also an interesting feature of Hiland M644 "quartz and ceramik resonators".
Is there a mod for support "quartz and ceramik resonators" in LCR-T7 and just enable it with define HW_FREQ_COUNTER_EXT?
I don't like Hiland M644 because use a not recharable battery, no ports protection and is not cheap.

[madires]

If that model got two unused pins and if T0 is also available then it should be possible to add the extended frequency counter. The next challenge is to make it small enough to fit into the case.

[juvann]

Looking at the schematics available online PB0 (T0) and other 3 pins are available
So I will buy and I will try the mod.
what will be the maximum frequency that can be detected?

Thank you madires for the help.

[madires]

I don't know the max frequency supported by the hardware of the extended frequency counter but for the MCU the theoretical limit is:
   f_max = MCU clock * prescaler / 4
(prescaler is 16 or 32)

[indman]

madires,are there plans future to add the SamplingADC function in your to doo list?
External additional modules are, of course, good and they expand the capabilities of the tester.But if it is possible to use internal reserves and processor capabilities for the same purpose, then why not?
This is аctual true for a small portable device.

[madires]

Back then when Karl-Heinz added PA3FWM's idea of the SamplingADC I had a look at it and my first thought was that it's an interesting concept. On the other side I'd prefer a proper LCR meter when measuring such tiny values. Weighing up pros and cons I decided to not implement the SamplingADC. But if someone likes to implement it for the m-firmware I wouldn't hesitate to add the code.

[indman]

But if someone likes to implement it for the m-firmware I wouldn't hesitate to add the code.

This is definitely a great motivation for those who want to thoroughly understand PA3FWM's code, but this task does not seem too easy to me. Maybe I'm wrong.

[coromonadalix]

I'm surprised to see the lack of mega 1280 - 1284  2560 series of arduino's  .... or diy  boards

With bigger display shield(s)  it could be evolved further without costing an arm

[indman]

coromonadalix What do you think this is? 
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3119442/#msg3119442
https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4504399/#msg4504399

[BroMarduk]

Not sure if this has been pointed out or not but there's a small bug in config.h

Line 2082 is where it starts:

This

Code: [Select]

/* variable Start_str */
#if defined (SW_OPTO_COUPLER) || defined (SW_DS18B20) || defined (SW_ONEWIRE_SCAN) || defined (HW_EVENT_COUNTER)
  #ifndef VAR_START_STR
    #define VAR_START_STR
  #endif
#endif
Should be:

Code: [Select]

/* variable Start_str */
#if defined (SW_OPTO_COUPLER) || defined (SW_DS18B20) || defined (SW_ONEWIRE_SCAN) || defined (HW_EVENT_COUNTER) || defined (SW_DHTXX)
  #ifndef VAR_START_STR
    #define VAR_START_STR
  #endif
#endif
At least that is the only way I can enable DHTXX without one of the others also enabled.

[Yuriy_K]

When setting up sampling_lc.c for the TTester on MEGA 2560, I noticed the dependence of low inductance readings on the connection to the inputs with direct and reverse switching. This dependence is also observed on other measuring instruments. See for yourself in the picture.

[Feliciano]

I don't know if that is an issue specific to the MEGA2560, but on other ctesters, I've noticed when I measure several times the same inductor --whithout moving it-- the results differ a little.

I haven't looked into the measurement subroutine, but maybe the method tends to let some remanent core magnetization. You may want to dig into that.

[madires]

The Transistortester uses DC for measuring inductance (standard measurement method, SamplingADC is a different story) while a proper LCR meter applies an AC signal.

[Yuriy_K]

I don't know if that is an issue specific to the MEGA2560, but on other ctesters, I've noticed when I measure several times the same inductor --whithout moving it-- the results differ a little.

No, the testimonies themselves are stable, all meaningful numbers. Indications have more value when connecting the lower output of inductance to the input "1" and less when connecting the upper output of inductance to the entrance "1". The method implemented in sampling_lc.c is very accurate. I only adjust it to the length of the internal compounds of the Mega 2560 in the range of 40 nH - 2 μH.

 Here is a fragment from ttester-1.13k en.pdf
"...Together with a parallel connected capacitor the inductor build a resonant circuit. With a
short current pulse this circuit begins to oscillate some times without further stimulation. With the
sampling method the frequency of this oscillation can be measured..."