$20 LCR ESR Transistor checker project

[madires]

I found that uncommenting #define HW_LC_METER produced this error. is that related to winavr toolchain somehow?

That switch is meant for the LC meter hardware option which is an additional circuit. Simply keep it commented out if you don't have that hardware option (commented out by default). The compiler errors are caused by the avr-gcc version you run, it doesn't support fixed-point variable types. Since fixed-point types are only used for the LC meter hardware option don't worry about that.

[madires]

Indman - sorry, I forgot to answer your final question - the screen indicates ST7735 on the reverse - photo attached.

That display doesn't seem to have a level shifter, only a 3.3V LDO. Does the old display have a level shifter (e.g. 74HC4050)?

[Steve3103]

Hello Madires,  thank you for becoming involved.  I have attached a copy of the screen as, even with a magnifying glass, I can not read what is printed on the chip.

[madires]

It's an HEF4050. If the LCD of the new module has the same flat-flex as the broken one you could use the new LCD with the old PCB to retain the level shifter (and the pinout). Otherwise you'd need to add a level shifter to the new display. The ST7735 is a 3.3V controller while the ATmega runs at 5V.

[Steve3103]

I will investigate and see what I can do.
Many thanks for your advice - much appreciated.

[drussell]

Hi, guys....

I'd like to get a couple of these tester-doodles but there is such a ridiculous number of variants, I don't know which one to buy (or more correctly I suppose, if there are any specific models that I should avoid.)

Specifically, is there anything wrong with this particular variant, I'm thinking of getting a couple of these:


This variant comes with a basic rechargeable Li-ion pack built in and with the current quantity discount, promotional codes, coupons and free shipping, I can get two of them for under $45 CAD total for the pair. 

That seems like a reasonable deal unless there is something spectacularly wrong with this model.

[madires]

TC-1's XXL drawback is U4, an additional MCU to control power and the test button. The other family members share the same design. If you like to run one of the two OSHW firmwares you need either to reprogram U4 or to replace it with a two-transistor circuit which also reduces the quiesent current dramatically. Some units come with cheap components in the power supply circuitry (shorted MLCCs, underrated Schottky diode or MLCCs for the 50V boost converter).

[Twiggy]

I found that uncommenting #define HW_LC_METER produced this error. is that related to winavr toolchain somehow?

That switch is meant for the LC meter hardware option which is an additional circuit. Simply keep it commented out if you don't have that hardware option (commented out by default). The compiler errors are caused by the avr-gcc version you run, it doesn't support fixed-point variable types. Since fixed-point types are only used for the LC meter hardware option don't worry about that.

Okay that about clears it for me, thank you for your firmware, your support, and also thanks again yuriy

[v81]

I've hit a roadblock as to what display i have.
It's colour, has 8 pins CD4050 chip on it.

ST7735 - You must set this display to config_328.h...

Thanks for that.
Have done this by removing the //#if 0 and //#endif for the section ..

Code: [Select]

/*
 *  ST7735
 *  - 4 wire SPI interface using bit-bang SPI
 */
Compiles and runs ok, but i get a grey screen when i hit the encoder button.
Any ideas?

Also is there any way to tell what display it is, like a guide or tell tale signs, or you just know it by sight or memory?

Out of curiosity i flashed the hex from the archive you linked from the Russian forum above and that worked OK, but the display was upside down.

[indman]

I have the code "ComponentTester-1.42m" and have made some changes to the make file, specifically the 20MHz xtal and some onewire stuff (it does currently read a DS18B20, and i'd like to keep that).
I've hit a roadblock as to what display i have.
It's colour, has 8 pins CD4050 chip on it.

There is no need  invent anything in a new way!
You have a standard kit for the AY-AT clone
Ready-made firmware for your clone can be applied directly from the k-firmware distribution
https://github.com/Mikrocontroller-net/transistortester/tree/master/Software/trunk/mega328_color_kit
AY-AT clone configuration settings for m-firmware can be viewed in the Clone file, which was kindly provided by madires
Ready-made k-firmware and m-firmware in English can be freely downloaded from my resource here
https://yadi.sk/d/yW8xa5NJgUo5z
For the AY-AT clone, you need to select the "M328Kit + TFT/Firmware/Markus Reschke/English" folder for downloading

[v81]

Out of curiosity i flashed the hex from the archive you linked from the Russian forum above and that worked OK, but the display was upside down.

Show the photo as inverted, it can be easily removed ...
This will probably be the solution to your problem ...
https://disk.yandex.ru/d/39xY4idSzvHvaw

This did not work at all.
Only a grey screen when the encoder button is held down.

The firmware you linked to in this post did work, but with upside down display.

Also i have modified the crystal to 20MHz

[indman]

Also i have modified the crystal to 20MHz

I suggest you return to 16MHz crystal. 20MHz does not provide any particular performance advantage, but it significantly reduces the stability work of the Chinese processor.

[v81]

Also i have modified the crystal to 20MHz

I suggest you return to 16MHz crystal. 20MHz does not provide any particular performance advantage, but it significantly reduces the stability work of the Chinese processor.

The original was 8MHz, and the interface was slow and clunky.
I might be better off switching to a unit with a mono display for better features and performance.
Would love to have the menu that was in the firmware of my original, supported extras like reading DS18B20 etc..

This did not work at all.
Only a grey screen when the encoder button is held down.

Also i have modified the crystal to 20MHz

I confirm the messages of indman, but for verification, here is the firmware for 20 MHz.
https://disk.yandex.ru/d/JDI0RR_KVcx1Xg

Thanks, I'll try this one.

[v81]

There is no need  invent anything in a new way!
You have a standard kit for the AY-AT clone
Ready-made firmware for your clone can be applied directly from the k-firmware distribution
https://github.com/Mikrocontroller-net/transistortester/tree/master/Software/trunk/mega328_color_kit
AY-AT clone configuration settings for m-firmware can be viewed in the Clone file, which was kindly provided by madires
Ready-made k-firmware and m-firmware in English can be freely downloaded from my resource here
https://yadi.sk/d/yW8xa5NJgUo5z
For the AY-AT clone, you need to select the "M328Kit + TFT/Firmware/Markus Reschke/English" folder for downloading

I'm actually intending to do some modifications, so i do need to re-compile the code.
I have already swapped out the crystal for a 20MHz unit, and i have a precision 2.5v reference ready to try.
In addition to that I'd like to incorporate any improvements recent firmware has bought.
Finally, I'm not super familiar with working outside the arduino IDE, so it's also a learning experience to learn to select the correct options and compile the code.
Flashing firmware intended for a clone which was originally 8MHz, but which has been modified to 20MHz will affect the test results i think.

[indman]

@v81 The folder "M328Kit + TFT / Firmware / Markus Reschke / English" contains ready-made firmware for 3 different clock frequencies 8MHz, 16MHz and 20MHz. Look carefully!

[v81]

v81 The folder "M328Kit + TFT / Firmware / Markus Reschke / English" contains ready-made firmware for 3 different clock frequencies 8MHz, 16MHz and 20MHz. Look carefully!

Tried this previously and it didn't work, but have since tried it again and it does work.
Have flashed it across 2 different MCUs and it consistently fails on one of them... possible counterfeit or dud???
I know one of them came with the component tester and the other is sourced via Element14 in Australia.

So now i have a couple of firmwares working on 20MHz

The ready made firmware above does not seem to have a menu or any way to interact with the rotary encoder, just seems to repeat the test over and over.
Is there a way to add OneWire functionality to it?

To you and Yuriy_K - i appreciate both your help.

[indman]

The ready made firmware above does not seem to have a menu or any way to interact with the rotary encoder, just seems to repeat the test over and over.

Read carefully the Tester Control Readme by madires. This must be done in the first place, if you want to use all the capabilities of the device correctly. Tester management on m-firmware differs from the work of k-firmware. See https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg3260672/#msg3260672

[hamlet600]

where can i calibrate zener reading in m-firmware?
thanks

[madires]

There's no need for an additional adjustment for the Zener voltage, because the normal adjustment takes care about the reference voltages anyway. However, the resistor values of the voltage divider for the Zener voltage could be off by some degree. There's also one clone which doesn't use the standard 10:1 divider. BTW, the next version of the m-firmware will allow to specify resistor values for a custom voltage divider.

[drussell]

TC-1's XXL drawback is U4, an additional MCU to control power and the test button. The other family members share the same design. If you like to run one of the two OSHW firmwares you need either to reprogram U4 or to replace it with a two-transistor circuit which also reduces the quiesent current dramatically. Some units come with cheap components in the power supply circuitry (shorted MLCCs, underrated Schottky diode or MLCCs for the 50V boost converter).

Ahh...  Thank you.

That gave me enough to search for everything I needed to know which was posted in various places earlier in this thread.  I see it is easy enough to modify that U4 circuitry to be generic (and essentially simpler and better!) if and when I move up to the generic open source firmware.

Thank you guys for all your hard work with regard to these units!!   

[hamlet600]

is there any option in m-firmware which generate predetermined pulse duration(for example 100ms)

[madires]

Not for a single pulse.

[hamlet600]

Not for a single pulse.

very usefull feature if you consider in next version update!

[XantheFIN]

I have read from here too that LCR meter can be used to measure Battery impedance if added example DC blocking cap.

I have here mega328_T4_v2_st7565 firmware installed at moment on mine cheap "LCR" meter and it shows resistance with that config plus capacitor but i am not sure what exactly it is and so i want check is it false reading and if its impossible.

I would be in time to check what are bad cells on my laptop battery.


If asked earlier i apologise.

[madires]

The Transistortester's ESR measurement can't measure battery impedance because it doesn't create an AC test signal.