$20 LCR ESR Transistor checker project

[Feliciano]

Did you replace the STC chip with the already discussed two-transistors circuit? Or you flashed that IC with the alternate firmware?
On the original TC-1 that MCU was in charge of controlling the turning on and off the CTester; the OSHW works in a different way.

[tedris]

My card is still with the original one. I just bought a new amega324pa and I'm trying to flash it with the software here. Is there any other change I need to make?

[Kim Christensen]

Like I mentioned in the other thread, did you program the EEPROM as well as the FLASH memory?

[tedris]

https://drive.google.com/drive/folders/19flDVmQclU_30opdUtMj_kIzZY0iK2bQ?usp=sharing

Yes, two files are flashed, they are also in the picture. Finally, the integrated system gave an error. He couldn't stand all this effort. I have 2 spare ones, but I won't try them unless I'm sure. His last chance may be wasted. I couldn't upload the pictures, I sent them to driva, I would be happy if you can look at them from there. At least all this effort wouldn't have been in vain. thanks

[Feliciano]

My card is still with the original one. I just bought a new amega324pa and I'm trying to flash it with the software here. Is there any other change I need to make?

As I said, the m-firmware is not meant to work with the original STC15L104W. You have two choices: you can a)remove it and add a two-transistors circuit, like in the attached schematic, or b)you could leave it but flashing a new firmware for that U4, which was shared here years ago.
For more information on how to make that TC-1 work with the official firmware, search on this thread around mid-2018.

[tedris]

I understood, thank you. If I disable Stc. Can I get an image on my screen? I just want to do this to test whether my screen is working and whether the integrated circuit is flashing. I will fix it later when I get the elements in the diagram.

[Feliciano]

Let me phrase it this way: the m-firmware assumes you're running one of the typical boards described in the clones file. The old TC-1 with its STC is not one of those. So, if that CTester were mine, I would read around page 195, and try to match what's described there, verifying it against your LCD connections. If your new ATmega is good and correctly soldered, nothing else got burned when you inserted the charged capacitor, and you follow without errors all the steps, you should get your unit working, like several of us have achieved.

I will fix it later when I get the elements in the diagram.

FYI:
1)I have made several of those circuits on veroboards with different values for transistors and resistors, and it worked because you only need those "to latch" when you press the power button
2)Some of the old TC-1 developed shorted capacitors/diodes on the power supply due the relatively high voltage of the Zener tester section
3)Probe there's no standard, the last TC-1 I got didn't require that other board or firmware for STC,  because it follows a different schematic. (But first I had to fix a bad solder job)

On the other hand, you're now on a point of no-return: you burned your old ATmega and now you have an useless board, so it's up to you to decide how much more time you want to spend/invest on this, and learn from it, or toss the unit and find another $20 one (being aware you probably won't get an original ATmega).

And off-topic: if any of our hints help you, there's the "Say thanks" button on this page

[Yuriy_K]

After placing the structure in the case and adjusting the frequency of the quartz generator in the Ttester itself, you can see the following picture of measurements...

Added external oscillator frequency measurements. Lower frequencies measurements are possible, but my homemade Si5351 oscillator cannot produce lower frequencies. External dividers must be added...

[tedris]

I decided to buy a new LCR meter. Can you recommend me a device that I can use with open source? Bangood, Sonara, Amazon and AliExpress.

[Yuriy_K]

Here is an example of a good kit for self-assembly. You can install both firmware versions of the k & m.
https://aliexpress.ru/item/32799188546.html?sku_id=65022357966&spm=a2g2w.productlist.search_results.4.477a5c4fEQX4jp

[tedris]

is it same ?
AliExpress'te bu muhteşem ürünü buldum. Hemen göz atın!
288,15TL | GM328A transistör test cihazı diyot gerilim frekans LCR metre PWM kare dalga sinyal jeneratörü monitör
https://a.aliexpress.com/_Eumslhf
There is no remote control, I wish there was an IR

[tedris]

AliExpress'te bu muhteşem ürünü buldum. Hemen göz atın!
531,42TL | Gm3transistor transistör test cihazı tip-c diyot kapasite direnci ESR gerilim frekans metre PWM kare dalga sinyal jeneratörü
https://a.aliexpress.com/_EuVjonX

[tedris]

Which one would be the one in the link I posted? I'm asking because I want it to be smd atmega

[Feliciano]

First, I cannot tell whether your screen is damaged or not, you may try to flash the alternate firmware to the STC and then try the m-firmware, or you could replace the STC with the other circuit as I told you before.

Besides that, the thing with the TTesters these days is the ATmega are hard to find in China, so they're using hardware and firmware alternatives, with sub-par quality, and not compatible with the original project. So you could cross your fingers and look for old stock of TC-1 or T7, if you want something similar to what you had. Or you could look for a DIP-28 unit which is more likely to be original. Regarding the IR, if you flash the official firmware, you could create an external add-on circuit for IR detection.

And please try to write in English. For the majority of us, English is not our native tongue, and we all make the effort of using the official language for this forum.

[madires]

There is no remote control, I wish there was an IR

No problem at all! The m-firmware supports an IR receiver module connected to a dedicated MCU pin or temporarily connected to the probes. And it detects up to about 20 protocols.

[tedris]

There is only 1 atmega processor left. I do the missile settings or crystal settings randomly and I think it breaks the atmega. I have the usbasp encoder but win10 sees it as ch340 and not usbasp. So I had to use it with Atmel studio. I adapted the settings myself and it is loaded at first but when I try to use the fuse settings many times because there is no image, the chip cannot be reached. Can you tell me the fuse settings and crystal settings, try it one last time. It has a 16000 crystal but atmel studio does not allow me to make any settings other than 8mhz. There are crystal settings in two places, when I select high on the first screen, it warns me to select 1/4, I tried 400mhz for 16000 etc. but there is no screen and I tried other things. I got ridiculous as I tried. If you can tell me exactly, I will try it, there is more than one code with the LCD model you recommended in the clone file. Like an equation with many unknowns? I am literally reinventing the device.

[Teoman]

Hello,

I am a beginner in electronics and I am researching the devices I need in my workshop. While trying to decide on one of the component testers mentioned in this title, I wanted to do some research and came across this OLED Screen Component Tester project whose link I shared. I would like to know what you think about this design. Thanks in advance.

Fareed Clarity
https://fareedish-blogspot-com.translate.goog/2023/10/membuat-oled-transistortester-v2.html?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=fr&_x_tr_pto=wapp

PCB
https://www.pcbway.com/project/shareproject/OLEDTransistorTesterRight_44370643.html

[indman]

Teoman, This is a compact version of the tester, but powering the microcontroller directly from USB is not the most correct option, which has its drawbacks. I don’t advise you to repeat it, unless as practice for entry-level self-assembly! 

[Teoman]

indman Thanks for your reply. I ordered a LCR-T10H from Banggood but I'm trying to research the best option for my level/needs.

LCR-T10H
https://fr.banggood.com/LCR-T10H-Transistor-Tester-Multimeter-TFT-Display-Auto-Measurement-3_7V-Lithium-Battery-25pF-100mF-0_01-50M-80x60x20mm-p-2017268.html?cur_warehouse=CN&ID=6327738

ArduTester PCB
I saw that Electronoobs' work for Ardutester Pcb.

https://electronoobs.com/eng_arduino_tut191.php

But I can't decide to buy a Chinese clone (I've bought already ). Can you advise me which one would be a better choice for me? DEER EE D5000, Hantek 1833C, UT622E, etc?

[indman]

Yuriy_K on the previous page showed a link to a version of the tester with a controller in a DIP-28 package. This is the option you should buy. You should not consider other options - there is a high probability of buying a disposable toy instead of a device. 

[Feliciano]

I have the usbasp encoder but win10 sees it as ch340 and not usbasp. So I had to use it with Atmel studio. I adapted the settings myself and it is loaded at first but when I try to use the fuse settings many times because there is no image, the chip cannot be reached. Can you tell me the fuse settings and crystal settings, try it one last time.

I have used the USBasp (set for 5V) under Win 7 and 10. No problems with Win10 after I installed the unsigned libusb drivers with the help of Zadig.

For compiling under Windows, we use WinAVR Programmer's Notepad, overwriting a wrong .dll, and integrating the 8.3.0 toolchain. And later I burn the binaries with AVRDUDESS.

Fuses for 8MHz or 16MHz full-swing Crystal:

Code: [Select]

# HFUSE = -U hfuse:w:0xd9:m
# EFUSE = -U efuse:w:0xfc:m
# LFUSE = -U lfuse:w:0xf7:m

All the details has been disclosed several times on this thread, so I'm not going to repeat it. You can search here the keywords for more information, and/or you can read the FAQ I wrote.

[tedris]

Although the ch341a programmer driver etc. is working properly, the programs do not see it. I am using win 10. When I open the program, it says it is not connected. The device manager says it is connected.

[tedris]

Thank you for the summary information. Okay, I did it. There is a problem and it keeps restarting like in the video. https://drive.google.com/file/d/189lygC9GednGO5T6VDAodPhylREtQRpi/view?usp=drivesdk

[Feliciano]

You didn't state whether you replaced the STC MCU with the two-transistor circuit, or you flashed that IC with the firmware that bypass its functionality, and whether the battery is connected or not, so I can't tell whether you have a power supply issue (brownout?), and/or a possible error on the replacement circuit, and/or other hardware/firmware failure.

I don't like the 18V battery reading, and some apparently dead pixels on the center of the screen, but in any case, to discard the firmware side you could try the russian firmware kindly shared by indman time ago.

[tedris]

Hello, I set the battery event and it almost measures the voltage. I pull up the settings +- and fix it to the full value, I turn the screen etc. no problem, I downloaded the u4.h file for STC from the given site and flashed it anyway, after that I saw an image on the screen. But it stays in this loop until the battery drops to the low level in the setting. Then it writes by and closes. Actually it does its job. But it seems to reset at the very measurement stage, I wish there was a debug so I could watch it from there, at what stage does it lock. I thought, is there no element to measure, I put a resistor, it's back to the beginning. Physically, the u5 integrated circuit on the card is heating up, I will add a picture. I checked the probe pins, it's the same with my card. As a result, solving the heating problem seems to solve the resetting as well. Could the u4.h file I uploaded for STC not be suitable for STC15L104W?
https://drive.google.com/file/d/18KBy8o6FPWjAloOuH0AoV-GisgGZXy4-/view?usp=drivesdk