[Mike Rozar]

Originally Posted by Larry Barello

The local io loop is very fast. I think I clocked it at a mere 29 cycles (doing nothing else, of course) which is many hundred thousand times per second.

HOWEVER, that isn't guarenteed! Once every 26.2 ms the main loop fires off and who knows how long that will take.

So I ran my encoder stuff off the PORTB 4-7 interrupt lines (IFI digital inputs 2-5), enabled the port B change interrupt so it interrupts whever any line changes.

When choosing encoders & such, keep in mind that the IFI CPU can only handle around 5-8 thousand counts/sec each for two encoders. So figure out how many RPM, how many slots (multiply by four for quadrature) and do the math. If you are substantially higher than 10k/sec total, then re-think.

I posted my quadrature code (including interrupt setup) in the thread about Yaw sensors.

Our team has assumed that since we are controlling the direction of the motors, we would not need quadrature for directional counting. Are we missing something?