Hi Paul,

Is there a reason to use 5% and measure pulse width?
Could you just count the revolutions, for a time period and multiply to get revolutions per minute?

Search the forum for: rpm*

http://www.picbasic.co.uk/forum/showthread.php?t=2811

http://www.picbasic.co.uk/forum/showthread.php?t=1150

http://www.picbasic.co.uk/forum/showthread.php?t=366

Skimask, the adjustable prescaler idea is a really good idea.

-Adam-