$20 LCR ESR Transistor checker project

[snapper]

@danielferran
Please take high-resolution photos of your bside tester with the new ATM328P and how you connected it to the programmer and upload them here.

[danielferran]

I have tried 2 arduinos as ISP, and tried to burn a New pro mini, but the same...

[danielferran]

Here friend... I have tried to upload in a pro mini board but the same happens.... with other Arduino I could upload an hex file normaly....

[snapper]

hi Daniel
you wired wrong, read here -->

https://docs.arduino.cc/built-in-examples/arduino-isp/ArduinoISP

where do the settings for the fuse bits come from?
I flashed my bside with low=CE, high=DF and Ext.=FF and it worked!

a new version AVRDUDESS is available here -->
https://github.com/ZakKemble/AVRDUDESS/releases/download/v2.14/AVRDUDESS-2.14-setup.exe

[danielferran]

Thank you, I Will try! i read about the wiring and in the sites they say this.... After I workout I Will try

[danielferran]

It is alive! Man, you help a lot! thank you!
I searched many sites on the web, tried many different softwares and configurations!
Is ther someone with the entire code? I would like to translate in portuguese...
The interface is different, but it seams that is working!

[snapper]

"I would like to translate in portuguese..."

https://github.com/Mikrocontroller-net/transistortester/

https://github.com/Mikrocontroller-net/transistortester/tree/master/Software/trunk

[Asko B.]

Hello
Sry, translatet by DEEPL

In the picture of user UltimateX, the board is labelled HW-849A.
The one I bought recently is labelled GM328A, but it is identical.
In principle, both versions are SMD versions of the AY-AT.

But what strikes me about the picture:
 https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4901579/#msg4901579
the capacitor "102" is missing at pin21 AREF.
Mechanically broken off or cold solder joint and fell off.

Greetings Asko

[indman]

But what strikes me about the picture:
 https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/msg4901579/#msg4901579
the capacitor "102" is missing at pin21 AREF.
Mechanically broken off or cold solder joint and fell off.

For modern firmware, this capacitor does not really matter, so it is not necessary to install it. You can read more about this in the manual from Karl-Heinz.

[Asko B.]

Hello indman,

I must have missed the part about the capacitor at AREF.

I also noticed that the voltage reference is no longer needed when using
MCP1702/1703 is no longer needed at all.
This was not the case in the days of K-Software < 1.xx.

At some point, the diode in the switch-on control also seems to be
disappeared (without a sound).

I wrote that the choke in the power supply of the AVR, which I had intended
power supply of the AVR is not needed, Karl-Heinz wrote to me a long
a long time ago.

Great! Three components less!
K.I.S.S.     

Greetings Asko

[madires]

The external 2.5V voltage reference makes only sense if the tester has a crappy 5V regulator. If you can get an MCP1702/1703 (0.4% voltage tolerance) go for it. The inductor in the Vcc rail is meant primarily as a filter for AVcc.

[MathWizard]

I have 1 of these generic ebay testers, from ~2017, IDK what chip, but with the big 2*4" screen or so.

But recently I took off a sot23 SMD part, marked as NAN, and the tester said it was a JFET, but with no negative rail, it said Vgsoff was like 63.2V and Idss was 2.8mA or something like that.

This thing seemed to check mosfets ok. Has anyone ever had a MOSFET read as a JFET on 1 of these testers?

Going by the pinot the tester said, I checked it with a dual PSU and it seemed to turn on at about -1.8Vgs, as I headed towards Vgs=0V, and at Vgs=0, it seemed to have an Idss of 10-20mA, with a 1k res. on the drain to Vdd, but with Vdd going past 23V, I seemed to have zapped it somehow.
more details below
https://www.eevblog.com/forum/repair/what-is-this-jfet-and-whats-its-purpose/msg4913053/#msg4913053


But I'm not sure if it was really a JFET, although if the tester pinout was correct, it never had any gate current, until I fired it a bit.

[madires]

Does your tester run one of two original OSHW firmwares or a modified one? Older firmware versions have an issue with confusing Germanium BJTs (leaky) with JFETs.

[Yuriy_K]

But I'm not sure if it was really a JFET, although if the tester pinout was correct, it never had any gate current.

To help you, we have to see your measurements on the display. For example, such as in the picture.

[Obelix2007]

Hi Yuriy,

I installed your ST7735_RGB_en16MHz software on my AY-AT today. Everything works fine so far - but it doesn't recognize any crystals  ?

Greeting Horst

[Yuriy_K]

Hi Horst,

The Mega328 does not have enough memory for such measurements. Mega644 or higher required.

[Obelix2007]

Hello Yuriy,

You are absolutely right, if you want to use all the functions of the KH 1.13 version, the memory of the Atmega328 is not enough.

So for this test I turned off the (CFLAGS += -DWITH_MENU) function and was able to use the quartz test function.

Greeting Horst

[UltimateX]

Hi,

Further to my previous post, I bought the USBasp ISP programmer and connected it to the dev board and my laptop (see photo).  I've launched Zadig and followed the https://www.instructables.com/USBASP-Installation-in-Windows-10/ instructions; however, the left Driver box shows "(NONE)", not "libusb0 (v1.2.6.0) as shown on the instructables image.  I selected libusb-win32 on the right Driver box and the installation successfully completed, according to the Zadig log.  I expected the driver (NONE) in Zadig to be replaced by the installed driver, but it still shows "(NONE)".  Furthermore, Windows 10 still shows "USBasp Driver is unavailable" under Windows Settings > Bluetooth and other devices.  Device Manager also shows "The drivers for this device are not installed. (Code 28)".

Any clues as to where I am going wrong? 

[UltimateX]

Sorted.  Didn't realise there are two installations (which the Instructable doesn't describe): one for the Windows driver and one for the WCID.  Getting the correct Zadig interface now.

[snapper]

don't forget the V-Target jumper!

[UltimateX]

Hi,

I have my USBasp connected and reading and writing with Extreme Burner (EB).  Referring back to post #8626, I installed the ATMega328P from the faulty GM328A in the chip reader and read the chip GM328A firmware into EB, then successfully wrote it out to a new ATMega328P.  I tried the new ATMega328P in my GM328A, but I still get the white screen a referred to in my post .  Could this be due to corruption of the GM32A firmware?  Is there a way of verifying the firmware or is re-flashing the latest GM328A firmware the quickest option?

Thanks   

[snapper]

please show what the SW reads!

[indman]

UltimateX,you need to fill in the controller with known working firmware and not the firmware you read from the ATMega328.
For example, this one I have attached below

[UltimateX]

Thanks Snapper.

My USBasp didn't come with one, but I had a spare.  The model of my USBasp looks different to your image and silkscreen printing on mine does not have "5V" and "3.3V" on JP1.  Mine has the same pin layout but with JP21 in place of JP1 and JP1 where JP2 is on your image.  I assumed it was the same and installed my jumper on the 3.3V pins.  Is this correct for ATMega328P?

[UltimateX]

If there is a particular piece of info you would like me to screen copy please let me know.  I have attached the .hex and .eep files (pls rename) in the meantime in case they are useful.

Thanks