[qsera]

I once tried to make a RC toy car so that it has proportional speed controls. I used some hall effect sensors to measure the speed at which the wheels are rotating and used it to compute the PWM signal that should be fed to the motor.

But the interference from the PWM signal appeared to mess with the speed sensor readouts that I couldn't make it work.

Can what you describe be used to solve it? If you would be kind enough to describe it, that would be great.

[chrisb]

I use an MT6701 magnetic rotary sensor mounted on the motor shaft, running in AB[Z] mode. This is used to measure the angle of the motor, and generate the correct PWM signals for the three motor coils. My inner current-control loop runs at 15kHz, using a PI controller.