AVR-based transitor tester

Posted on Tuesday, December 13th, 2011 in Development by DP

After our recent post about the commercial semi-conductor tester we started a discussion about building a similar open source project. What came up is this AVR based transistor tester (machine translation) by Markus.

It’s built around an ATmega8 IC that interfaces with a standard HD44780 16×2 character LCD. The circuit that does the testing is simplicity itself. Three pairs of resistors are connected to 6 pins of the microcontroller, and each pair is connected on the other end to one of the transistor pins.

The theory of operation is also relatively simple. The microcontroller cycles through different patterns on its output pins until a recognizable pattern is read on its input pins. It supports a very large range of devices:

Arup and Fcobcn have already built one for themselves. Join the discussion and add your input to our development of an open source part tester.

Via the forum.

This entry was posted on Tuesday, December 13th, 2011 at 6:00 pm and is filed under Development. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “AVR-based transitor tester”

  1. tbutuza says:


    It is a nice device / project.
    For the DP version I could recommend using different LCD.
    I feel 2×16 chars resolution is too small. 4×20 chars were better, graphic LCD would be the best.


  2. Marcin says:

    It would be nice to add zener diode detection, and measure the breakdown voltage.

  3. Joe says:

    This is impressive. Wonder if it could be adapted to test the impedance of an FPGA iostandard.

  4. Hey guys I built a version of this using my CNC machine to make the case. Really happy with the device, and very well done in both software and hardware design. I might fiddle a little with the software to unify the display output a little and also attempt to add maybe zener detection and maybe even rudimentary inductor measurement.

    Let me know what you think.

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