Mark Jenkins wrote: > I am in need of some advice regarding the possibility of using a > pic16f84 or any other kind of pic to sense the speed of two seperate > wheels. What I would like to do is to be able to turn a led on if the > speed of one wheel increases to a speed of say for example 10% over > the other. Sounds entirely practical. May we assume you have optical "choppers" on each wheel which have approximately equal mark and space, and anywhere between one and 64 "chops" per revolution? Should be no trouble. I'm too tired now, going to bed, but may have an algorithm figured in the morning (unless everyone else gets there first). -- Cheers, Paul B.