Originally Posted by Roelof

I know a lot of electronics but know nothing of programming uP's (although I do know what is possible with them), I have a Arduino starterskit to start with but have still so many other things to do in my mind....

Basically a simple phase detector should be able to detect a positive/negative timing and that can be done with some simple logic components.

On the other hand, a simple DSO201 oscilloscope is very affordable and easy to transport.