$20 LCR ESR Transistor checker project

[LinuxHata]

I have two different models, one with B/W 1602 LCD screen (the model with red pcb and space for 9V battery), and another one with color graphical LCD. (GM-328)
Haven't touched firmware at all, but both work in the same way - a press of the button goes each time thru the initialization sequence, which is very boring

[madires]

There's the k-firmware (https://github.com/kubi48/TransistorTester-source) and the m-firmware (https://github.com/madires/Transistortester-Warehouse). Maybe the m-firmware would be the better choice for you since it offers several options to customize the UI. Try the slightly older version 1.45m (1.46m has a small font issue impacting the GM-328A).

[LinuxHata]

Thanks, and is there a brighter and bigger display option for that color one?
I've set custom colors to white, but it is still quite dim.
In fact, I need to know display controller and pinout, and I'll handle other things by myself.

[Per Hansson]

I have no idea what version that is, but trying a OCR translation it seems to be saying that the USB port is only for user upgrades (of the firmware) and that it does not supply power.

Then it should be possible to update the firmware directly via avrdude.

Just noticed there is an unpopulated 0Ω resistor R12 near the USB port.
This would power the device directly with the VCC from the serial port, not through any regulator it seems.
I wonder how well the LMV358 (U5) works as a voltage reference in this implementation.
It would be interesting to see a schematic of this unit, have you tried asking the seller @lusant?
Sometimes they have been strangely forthcoming with that...

[lusant]

Just noticed there is an unpopulated 0Ω resistor R12 near the USB port.
This would power the device directly with the VCC from the serial port, not through any regulator it seems.
I wonder how well the LMV358 (U5) works as a voltage reference in this implementation.
It would be interesting to see a schematic of this unit, have you tried asking the seller @lusant?
Sometimes they have been strangely forthcoming with that...

Yes, there are 3 missing resistors, that one of 0 Ohm, and more two R15 and R16 of 5.1k, these are for terminating the data lines of USB, I suppose.
The funny thing is, when supplied from USBC plug (with the mobile charger) and without battery, the display shows the message MTester and also the voltage level, 7. something Volt (it is in the box, which does not allow access to the plug, and I need to open it to connect and the be more precise).
So, anyhow the cpu is running, maybe waiting for k2 pressing and some bytes of data from USBC.

If you guys need, I can make some measures to clarify some connections.
This is my first LCR of this kind and I was surprised when I saw the USB stuff.

I don't have any schematic and I doubt the seller will send it, I can try, but ...
I bought this module two weeks ago from Aliexpress in one seller named FNIRSI Factory Store. It cost me 13.98 € with the box and the test wires and now it cost 17.06 €. The pictures in the advertising doesn't show the bottom of the PCB.

[madires]

Thanks, and is there a brighter and bigger display option for that color one?
I've set custom colors to white, but it is still quite dim.
In fact, I need to know display controller and pinout, and I'll handle other things by myself.

The LCD controller and the pinout for the GM-328A is noted in the 'Clones' file. You can replace the display with a larger one if you like, e.g. ILI9341/ILI9342. Or try to change the resistor for the LED backlight.

[Yuriy_K]

Thanks, and is there a brighter and bigger display option for that color one?

If desired, can be converted to displays ILI9341 2.8"

[LinuxHata]

Thanks, will check it tomorrow.
And another question, my another one, with 1602 LCD, often makes same error - capacitance is displayed as 86.XX something, and ESR as 0.14K (always these values).
I've re-checked wiring, even replaced IC socket, but that does not helps. Any ideas, what can be causing this ?

[Yuriy_K]

... Any ideas, what can be causing this ?

It is necessary to look at the readings of self-tests, whether there was a replacement of the crystal, and it is possible to change the LDO, adjust the blocking capacitances ...

[madires]

And another question, my another one, with 1602 LCD, often makes same error - capacitance is displayed as 86.XX something, and ESR as 0.14K (always these values).
I've re-checked wiring, even replaced IC socket, but that does not helps. Any ideas, what can be causing this ?

Powered by SMPSU, unstable voltage regulator or self-adjustment not done?

[Per Hansson]

Can someone that has compiled Madires M-firmware for the Hiland644 post the config files here so I have something to start from?
I looked through the thread but could not find anyone that had posted a working config before?
Pictures of my meter: 1, 2.

[madires]

The required settings for the Hiland M644 are listed in the 'Clones' file (part of the firmware archive).

BTW, the new GM328A model with the black round PCB runs fine with the Semi-ST7735 driver.

[Yuriy_K]

Can someone that has compiled Madires M-firmware for the Hiland644 post the config files here so I have something to start from?

Verified changes for Hiland.

[indman]

BTW, the new GM328A model with the black round PCB runs fine with the Semi-ST7735 driver.

Yeah, it's true. For this "GM328A(BGR)2" clone I added actual k-firmware 1.13k and m-firmware 1.46m in English for 8Mhz to my firmware collection  https://yadi.sk/d/yW8xa5NJgUo5z
Also added a schematic diagram for this clone (thanks to the member of the forum 4pa.to vad.leo for creating it).

[Per Hansson]

The required settings for the Hiland M644 are listed in the 'Clones' file (part of the firmware archive).

Thank you!
Maybe something to change: in the 1.46m archive the "ILI9342" LCD is enabled with:
//#if 0 in config_644.h this took a while before I realized because Notepad++ did not do proper syntax highliting.
It was not until I viewed the file with VIM that I realized why I only had a white screen on my tester after loading the firmware on it...
The reason I think this is a mistake is that further down is this code, but it will obviously never be invoked to help the user as it is now.
Maybe it could even be improved to check if multiple displays are enabled, unless there is some use case for that?
(P.S: Not relevant for my compile but in config_328.h "ST7565R" is enabled by default instead).

Code: [Select]

/*
 *  check if a LCD module is specified
 */

#if !defined(LCD_TEXT) && !defined(LCD_GRAPHIC)
  #error <<< No LCD module specified! >>>
#endif
Lastly I think the "Clones" file should mention that you should change the MCU type in the Makefile from the default atmega328 for those models where that is relevant.

Everything should be 0xFF. Write the desired values: L = 0xFF, H = 0xD9, E = 0xFC, LB remains 0xFF.

The recommended setting of the low fuse for the Hiland M644 (ATmega 644, 8MHz) is 0xf7.

I know this is an old message but I have to ask why? Does this disable the external 8Mhz crystal and use the internal RC crystal, if so what is the purpose of this change, and if I misunderstood it can you please explain?

Verified changes for Hiland.

Thank you! I had already done pretty much exactly the same changes as you when I saw your message, but I did borrow some of them now!
But a question for you: does your tester not require the hFe fix? Mine does, it displayed way too high values otherwise, after enabling the fix it shows the same as my other tester:
#define NO_HFE_C_RL

[Yuriy_K]

But a question for you: does your tester not require the hFe fix?
#define NO_HFE_C_RL

My previous post shows a photo of my Hiland board. You can see some changes, but there are also not noticeable ones, these are C4, C3, C10 values. I don't need to enable this option.

[Per Hansson]

But a question for you: does your tester not require the hFe fix?
#define NO_HFE_C_RL

My previous post shows a photo of my Hiland board. You can see some changes, but there are also not noticeable ones, these are C4, C3, C10 values. I don't need to enable this option.

Thank you, I remember you posted about the high resistance for the VCC and GND traces on the Hiland board a long time ago but I can't find the post any longer.
Could you detail what the different mods achieve / what improvement you see in the behavior with your changes?
1: GND/VCC lower resistance traces
2: C10 input and C4 output capacitor for IC1 1117M3 voltage regulator, and what values do you use? Just recommended from the datasheet?
3: C3 capacitor, did you change it or just add the one that is directly on pins AVCC to AGND of the Atmega644?
4: C8 fixed capacitor for self-adjustment
5: Anything I missed? (except for precision test resistors, those are obvious what they do...)

[Obelix2007]

Hi Yuriy,

... could you please tell us the values of the capacitors?

Regards Horst

P.S.

sorry for the overlap

[madires]

Maybe it could even be improved to check if multiple displays are enabled, unless there is some use case for that?

Another good idea for the to-do list.

Lastly I think the "Clones" file should mention that you should change the MCU type in the Makefile from the default atmega328 for those models where that is relevant.

RTFM (please see README, section 'Building the Firmware')!

The recommended setting of the low fuse for the Hiland M644 (ATmega 644, 8MHz) is 0xf7.

I know this is an old message but I have to ask why? Does this disable the external 8Mhz crystal and use the internal RC crystal, if so what is the purpose of this change, and if I misunderstood it can you please explain?

0xf7 enables the external quartz crystal and sets the prescaler to 1:1. The ATmega's default setting is internal RC oscillator and 8:1 prescaler.

[Per Hansson]

RTFM (please see README, section 'Building the Firmware')!

Well the little note would not hurt to add to the "Clones" file IMO

0xf7 enables the external quartz crystal and sets the prescaler to 1:1. The ATmega's default setting is internal RC oscillator and 8:1 prescaler.

I had to re-read the Atmega644 datasheet about 28 times but I finally got it, the most important piece of the puzzle when reading the datasheet is this:

Note: 1. For all fuses “1” means unprogrammed while “0” means programmed.

With it programmed with 0xFF it sets all bits to "1" meaning unprogrammed, this means that the oscillator has a limited frequency range of 8 to 16MHz and startup mode: "slowly
rising power" this is a low power operation mode for the crystal oscillator.
With it programmed with 0xF7 instead the CKSEL3 bit is progammed and this means that the crystal oscillator has a frequency range of 0.4 to 20MHz with the same starup mode as before, this is a higher power mode for the crystal oscillator.

Here it is in practice, measured with a 100:1 probe to affect the drive level as little as possible, 1.3v vs 5.4v as you can see:

[Yuriy_K]

Anything I missed? (except for precision test resistors, those are obvious what they do...)

You've got almost everything right. Here is the full scheme of changes and an enlarged view of the board. Enlarged view of T1, location in the case and the use of additional sockets, for the resonant method of measuring small inductances.
When selecting capacitances, one should take into account the change in capacitance and ESR values after heating the soldering points. It may take several hours to restore the original values. It depends on the type of ceramic. In the first two pictures, cold capacitors, in the next picture after warming up.
On my homemade Ttesters with ILI 9341 (built according to the Hiland scheme) I experimented with various changes in the Hiland scheme. To improve the stability of the readings and the correct measurement of the ESR of electrolytic and film capacitors, I selected the indicated capacitors, I don’t know their type, but they are soldered from cell phones of well-known companies. On a self-made capacitance meter, I can see the capacitance value of 5-6 characters. In the continuous measurement mode, you can judge the stability of the readings of these containers as they warm up. All significant changes obtained during experiments on homemade products were transferred to Hiland. Important, all changes are individual, adjusted to the installed ATmega644 and may have deviations from those indicated in this scheme. When selecting blocking containers, I paid special attention to the correct ESR. If the capacitance value is insufficient, the readings are underestimated. If the capacitance is too large, the readings are more than necessary. This is exactly for ATmega644, for circuits with ATmega328 it's the other way around.
This is a very simplified explanation.

P.S. Perhaps this is not true for most Hiland users. All my alterations are designed for firmware with increased up to 4 digits for measuring inductances and up to 5 digits for measuring capacitances. This was first worked out on homemade with ILI9341 in color, and then I transferred the changes to the sources for Hiland but the line length should be 20 characters. This is only possible with my font with a different display approach compared to the original "k" version. For this reason, I do not distribute the sources for the "k" version.

[Per Hansson]

I have a question about the rotary encoder on my Hiland 644.
It does not work so well with M-firmware, and I found something strange:
On channel B the voltage is 4.97v but on Channel A it is only 460mV.
I checked the pullup resistors R3 & R4 and they are 10K as they should.
And then the PB5 & PB7 resistors R6 & R8 are 1K as they should.
Is this normal behavior or what could be causing this?

In addition I measured the A and B channels with my scope like I did on my other component tester.
I used 10:1 probes for both channels, yes I know, it looks like I fucked up the probes or settings but it really is like this!


I used the Zener page because that does not write to the display: so it is much easier to scope gray codes, otherwise it looks like this:

You've got almost everything right. Here is the full scheme of changes and an enlarged view of the board.

Thanks Yuriy_K! If you could just describe what problems the different changes solve that would be nice, except the obvious ones of course
P.S: Do you have a link for a higher resolution version of the schematic than the one on Indman's Yandex site?
P.P.S: Two errors in that schematic I noticed: R17 connected to base of T3 should be named R19 and R3 and R4 should swap places.

[indman]

P.S: Do you have a link for a higher resolution version of the schematic than the one on Indman's Yandex site?
P.P.S: Two errors in that schematic I noticed: R17 connected to base of T3 should be named R19 and R3 and R4 should swap places.

Thank you, I corrected the errors in the circuit that you found! I am attaching the corrected scheme in the highest possible quality for SPlan in jpg format

[madires]

I have a question about the rotary encoder on my Hiland 644.
It does not work so well with M-firmware, and I found something strange:
On channel B the voltage is 4.97v but on Channel A it is only 460mV.
I checked the pullup resistors R3 & R4 and they are 10K as they should.
And then the PB5 & PB7 resistors R6 & R8 are 1K as they should.
Is this normal behavior or what could be causing this?

In case of the Hiland M664 PB5 and 7 are shared between display and rotary encoder. Both I/O pins are set to output mode at startup, and when waiting for user feedback the pins are temporarily set to input mode to poll the rotary encoder every few ms. What you see can be normal at a specific time (pin setup).

[madires]

This time we have done some work on the display output.

v1.47m:
- Fixed swapped resistor symbols in font_8x12t_iso8859-2_vfp.h and font_8x12t_iso8859-2_hf.h (reported by b0hoon@EEVblog).
- Added option to display quartz crystal symbol for LF/HF modes in extended frequency counter (UI_QUARTZ_CRYSTAL, suggested by indman@EEVblog).
- Added fonts font_8x12t_iso8859-2_hf.h (FONT_8X12T_ISO8859_2_HF) and font_8x16_iso8859-2_hf.h (FONT_8X16_ISO8859_2_HF, thanks to b0hoon@EEVblog).
- Fixed wrong reference of '\' in font_8x8_iso8859-2_h.h, broken diode symbol A-C and 'W' in font_6x8_iso8859-2_hf.h (Thanks to b0hoon@EEVblog).
- Added option to display a Zener diode symbol in any Zener check (UI_ZENER_DIODE, suggested by indman@EEVblog).
- New 32x39 symbol set to match 26 pixel high fonts (SYMBOLS_32X39_HF, thanks to indman@EEVblog).
- Added options to auto-hold ESR and inductance for C and L monitor (SW_MONITOR_HOLD_ESR, SW_MONITOR_HOLD_L, suggested by theHWcave@EEVblog).
- Added character translations for inversed pin numbers to Serial_Char().
- Added option for /RESX line on separate MCU port to ST7735 driver (LCD_RES_PORT, LCD_RES_DDR, based on idea from lhlad@EEVblog).
- Added option to display a question mark symbol in case of a failed test run (UI_QUESTION_MARK, suggested by indman@EEVblog).
- Added symbols for question mark, Zener diode and quartz crystal to all symbol sets (thanks to indman@EEVblog).
- Added additional positioning flags for fancy pinout (PIN_CENTER, PIN_ALT_CENTER, suggested by indman@EEVblog).
- Display small diode symbol in front of Vf for MOSFETs and IGBTs (suggested by indman@EEVblog).
- Added numbers 1-3 and character x with reversed color plus degree character to font_8x16alt_win1251_hf.h. Also updated 1-3 and x with reversed color in font_8x8alt_win1251_vf.h. Same for font_16x26_win1251_hf.h (thanks to indman@EEVblog).
- Added option to disable display of text based pinout of the body diode for MOSTFETs (UI_NO_BODYDIODE_TEXTPINOUT, suggested by indman@EEVblog).
- Added symbol set 32x39 (SYMBOLS_32X39_HF, thanks to indman@EEVblog).
- Added alternative symbols sets 24x24 (SYMBOLS_24X24_ALT1_H, SYMBOLS_24X24_ALT2_H, SYMBOLS_24X24_ALT1_HF, SYMBOLS_24X24_ALT2_HF, SYMBOLS_24X24_ALT1_VFP, SYMBOLS_24X24_ALT2_VFP, SYMBOLS_24X24_ALT1_VP_F and
SYMBOLS_24X24_ALT12_VP_F), 30x32 (SYMBOLS_30X32_ALT1_HF and SYMBOLS_30X32_ALT2_HF) and 32x32 (SYMBOLS_32X32_ALT1_HF and SYMBOLS_32X32_ALT2_HF, thanks to indman@EEVblog).
- Added option to fancy pinout to show right-hand probe numbers above/below the symbol (UI_PINOUT_ALT, suggested by indman@EEVblog).
- Fixed issue in FontTest() with missing spaces for some display drivers.
- Added test output of component symbols (SW_SYMBOL_TEST, suggested by indman@EEVblog).
- Updated Russian texts (thanks to indman@EEVblog).
- Fixed missing ')' character and broken '*' in font_10x16_hf.h (reported by pepe10000@EEVblog).

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