Measuring the gain of a NPN or PNP transistor.
The circuit and the software are modified versions of 'the transistor test circuit by Burkhard Kainka' on

http://www.elektronik-labor.de/AVR/NPNpnp.html

There an ATTiny13 is used and the data is sent to a PC via RS232

Here the test is done by an ATMega8 or ATMega88 and data is displayed on a LCD display.

For PNP transistors the collector and emitter have to be connected in reverse.

I only had a 20 * 2 LCD but a 16 * 2 or even smaller LCD is also o.k..

On the left picture the transistor under test can be seen - in this case a BC548B.

Thanks to Burkhard Kainka for the permission to adapt his project.