mikep

While agree that you should not worry about interrupts in general, using any routine that has timing in it i.e. Serial will get messed up. LCD routines though do not from my experience suffer.

Concidering the requirements he has you could happly implement a counter based on direct interrupts when he gets a pulse or using a counter to do the counting for you. One thing you do need though is a time base to work to. No good saying you have received 100 pulces if you do not know over what period you collected them.

I decided this would make a good project so am currently writting an artical how to count pulces over a preset period, all in the back ground via an interrupt routine. Just read the result when required. Should be operate from 4hz to about 26,000 hz (or a bit more). I will let you know when it's done.

Tim