How then do we use the current readings? Near max rpm with normal load, the current should be stable. With no load at max rpm the current should still increase, does that differ from normal load when at an average rpm?
At low rpm the current will increase a lot, will the same thing at no load average rpm?
The first may not be able to stop over-revving the motor, the second may be exactly what Paul wants.
What about the current decay, does it always decay at the same rate as it increases, under the same load and speed?
Paul if you're going to do some testing, I suggest you do the timing thing, or on a button, and then do what mcudogs suggested. Turn on the pwm full, run several concurrent current readings (4 or 5) (should be safe 13*(4 or 5)*adc clock ~65us). Then turn the pwm to 0 and again run several readings. Then go back to normal control. I'd have my hand near the contactor just in case.
