Hi Henrik,

Nothing is set in concrete on this project!
8kHz is the PWM frequency now but it can be changed. I don't know what the down side would be, if any, to increasing the PWM frequency but I am willing to give it a go if it will help things overall.

I chose 60 steps per revolution on the encoder wheel because a) it was easy to achieve and b) it made RPM calculation easy.
I have now played with period measurements using the 18F2431's IC module so there is less reliance on the original step rate.

Given the inertia of the final system, what would be the expectation for the number of steps per revolution, interrupt rate and minimum motor speed to achieve a nice, tight PID operation?

Cheers
Barry
VK2XBP