Dear Mr. Jacek Bogusz,

EDN magazine has a excellent article telling how to build a frequency counter using an Atmel 89C2051 Microprocessor. It has source code, schematic and a description.

It should be everything you need to count your signal.

The address is http://www.e-insite.net/ednmag/in...mp;stt=001

Good luck,

Charles Bannister