Add more io

Projects General Guidance
11

I don't think you really need to know 3000RPM as such, just that you get pulses faster than 1 every 20mS.

As such you could do something like

period = pulseIn(pin, HIGH);
period += pulseIn(pin, LOW);
if (period > 20000)
   // too slow

This would give you a reading for one channel in two revolutions, x 40 that's 800mS to read all motors.

Rob