vitesse1508 - 2009-08-31

Hi guys

As you know im very new to using pic's and im very stuck on this. I'm trying to monitor the speed of a couple of computer fans and then output the rotation speed (rpm) to an LCD display. I've tested this out on a usb interface board I have using vb.net to code it and it appears that the fan gives a single pulse per revolution and i've used some simple maths to work it out

so count pulses for 1 second * 60 = RPM of fan

The problem i've got is im now clueless as to how to achieve that with a pic :) i'm assuiming i'd have to use a timer of 1 second interval and for the duration that timer is running keep adding 1 to a integer variable until the timer elapses then maths on that value and reset var to 0.

The other problem i can see with this is doing 2 or more fans at the same time, as this will need to use separate timers for each?

Any guidance in the right direction would be greatly appreciated

Thanks

Tom