Author Topic: The $20 LCR ESR transistor tester  (Read 7165 times)

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Offline The Radio Shop

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The $20 LCR ESR transistor tester
« on: February 25, 2015, 10:47:34 AM »
This was the first tester I purchased.  Worked really good.
Then one day testing a 100uf cap I forgot to discharge the tester took the load of the cap.

It now fails to come on. So perhaps it took out some components or maybe wiped the processor.

I am going to install a header and see if I can communicate to the processor.
Buddy kc4umo

Offline The Radio Shop

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Re: The $20 LCR ESR transistor tester
« Reply #1 on: February 25, 2015, 01:22:45 PM »
Well perhaps I was wrong about the controller being dead. After installing the pin header I was able to read the contents from the Atmega 168 chip.

After doing this I noticed something that was not happening before.  When ever I connected the battery to the device and hit the test button nothing happened. No display no red LED.
But now when I hit the test button for a couple of seconds I get a message on the LCD.

"BAT 4.8V empty"

I know my battery is good and test at 9 volts. So I but my DMM across the battery leads and when you hit the test button the voltage drops from 9 to 4 volts.

Looks like I need to check some on board components and see if any are failing.
Buddy kc4umo

Offline The Radio Shop

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Re: The $20 LCR ESR transistor tester
« Reply #2 on: February 25, 2015, 09:30:05 PM »
schematic
Buddy kc4umo

Offline The Radio Shop

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Re: The $20 LCR ESR transistor tester
« Reply #3 on: November 07, 2015, 10:01:09 AM »
I have yet to get this thing programmed.
If someone could do a YT video would be great.
I am not that good when it comes to piks and atmels
Buddy kc4umo

Offline The Radio Shop

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Re: The $20 LCR ESR transistor tester
« Reply #4 on: November 10, 2015, 07:55:38 PM »
Linking in this info from Tom666 over at the EEVblog.

http://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/1470/


Procedure for flashing a firmware into MCU (ATmega328P) with the USBasp programmer:

Required hardware:
- USBasp (price around US $1.87)

Required Software (download links below):
- USBasp Driver
- AVRDUDE
- Firmware

1. Unzip the downloaded files into a separate directory and then perform the installation USBasp driver.
2. Then connect (through the ISP cable) the USBasp programmer with the ISP connector on the tester.
3. Navigate to the folder with the unpacked software and perform this following command from command line:
avrdude -c usbasp -p m328p --B 4.0 -e -U flash:w:"TransistorTester.hex":i -U eeprom:w:"TransistorTester.eep":i -U lfuse:w:0xF7:m -U hfuse:w:0xD9:m -U efuse:w:0x04:m
This command (also includes a section for writing fuses) can be copied and saved as e.g. "flash.bat" and stored in a prepared folder. In the future you can simplify this flashing of the firmware by the usage of "flash.bat".

Links:
USBasp - Driver:
http://www.fischl.de/usbasp/usbasp-windriver.2011-05-28.zip
or
http://www.protostack.com/download/USBasp-win-driver-x86-x64-v3.0.7.zip

AVRDUDE:
http://download.savannah.gnu.org/releases/avrdude/avrdude-6.1-mingw32.zip

Firmware:
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/trunk/mega328_2X16_menu/?view=tar

USBasp - How to install driver on Windows 8:
http://letsmakerobots.com/node/36841

USBasp - How to install driver on Windows 8.1:
http://openchrysalis.wordpress.com/2014/09/26/installing-usbasp-driver-software-in-windows-8-1/

USBasp - User Guide:
http://www.protostack.com/download/Users%20Guide%20(AC-PG-USBASP-UG-V2.0).pdf
Buddy kc4umo

Offline The Radio Shop

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Re: The $20 LCR ESR transistor tester
« Reply #5 on: November 13, 2015, 08:50:27 PM »
board test
Buddy kc4umo