$20 LCR ESR Transistor checker project

[indman]

You need to check ATMega328 with a programmer.

[UltimateX]

I have the one in the attached photo.  Are there instructions somewhere on how to check, test, dump the chip contents, etc?

[indman]

I have the one in the attached photo.  Are there instructions somewhere on how to check, test, dump the chip contents, etc?

In your photo, this is not a programmer, but an attachment to the USBASP programmer. Do you have USBASP?

[UltimateX]

I don't have USBASP but I thought I could upload new firmware to ATMega chips with the USB attachment.  Can you suggest what I should I get to check and test my ATMega328?  Thanks.

[snapper]

https://www.ebay.co.uk/itm/255552888808

the atm328 of the chinese clones are mostly read protected, so you can only load a new firmware!

[UltimateX]

Thanks snapper.  So I buy the"USBasp ISP Programmer including cable" in your link and connect it to the chip writer device I showed in my photo previously, right?

[snapper]

Yes is correct, but you still need software, I use this

https://extremeelectronics.co.in/avr-tutorials/gui-software-for-usbasp-based-usb-avr-programmers/

http://digitalwizard.co.in/download.php?file_name=extreme_burner_avr_v1.4.3_setup.exe

close VTarget jumper on the USBASP board and the usb connection to the board with the 28pin socket is then not needed.

https://www.fischl.de/usbasp/

[UltimateX]

Thanks very much, snapper.  I will take a look. 

[danielferran]

hi, i am trying to put the firmware one new 328P, cause I burned the original one of the device, but there is an error on AVRDudess.... could anyone help me? i am a dumb in burning HEX files... sorry for my english to... i am using arduino isp..


Using the AVRDUDE Software it shows this error...on the att
 

[Fuzzy Star]

hi, i am trying to put the firmware one new 328P, cause I burned the original one of the device, but there is an error on AVRDudess....

Using the AVRDUDE Software it shows this error...on the att
 

Looks like your 'new' 328P is faulty. Where did you get it?
Are you sure your programmer is connected correctly?

[danielferran]

I have checked the connections, the 338p IS New, from Aliexpress... I don't know, we have to burn a bootloader ir something like this on the New chip?
i have other 328p, but I don't know, os ter something measing?

[indman]

danielferran AVRDude tells you that the ATMega328 is not detected. If you have other ATMega328 check them also by connecting to the programmer.

[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.