I am trying to implement a FOC algorithm in an MCU to use with a BLDC motor.

My problem is that I only have the Hall sensor feedback, no precise encoder can be used. With this 4 pole pairs motor, Hall sensors give 15 degree resolution.

I think this is the reason my algorithm is failing and I cant get a DC constant d and q values.

Is there any better way to drive a BLDC motor than FOC? What I need actually is a way to feed torque/ current to the regulator and be able to precisely read the feedback.

My analog circuitry for measuring \$I_a\$ and \$I_b\$ currents works fine, I just don't know how to calculate the needed feedback value.

In other words, can FOC even work for BLDC without an encoder but just with Hall sensors? If not, what is the better way?