I want to design a circuit with an H-bridge to control a brushed DC motor. In order to control its speed, I want to measure the back-EMF of the motor and make a PID control loop in software. I do not want to use external sensors for a number of reasons.
I want to build a circuit around a DRV8220 chip. It is a small chip, the specifications suffice, it is affordable and most important, it is in stock at my PCB supplier.
The motor has to be able to turn in both directions and may experience different loads.
Can I build a circuit around this chip in order to measure the back-EMF of a DC motor?
If so, what would it look like?