[dcbrown]

gryo w/drift compensation and programmable op-amp gain (similar to those used on model helicopters like ICG400).

sensorless motor feedback using back emf measurement sync'd with pwm cycle (i.e. automatically interrupt pwm setting, substituting neutral for a couple of cycles, but sync'd with start of pulse train). programmable op-amp gain would be a bonus. Should be available on any pwm output, but would require A/D channel to get the measurement. Would need sync signal on when to acquire analog sample.