Methods and apparatus to detect a stall of a stepper motor

At least one non-transitory computer readable storage medium comprising instructions that, when executed, cause programmable circuitry to at least:

• determine a first value of power transferred to a stepper motor during a first operation of the stepper motor;
• determine a second value of power transferred to the stepper motor during a second operation of the stepper motor;
• determine a load angle of power delivered by the stepper motor during the first operation and second operation of the stepper motor based on the first value, the second value, and a stall power;
• and
• compare the load angle to a stall threshold to detect a stall of the stepper motor.

A method comprising:

• determining a first value of power transferred to a stepper motor during a first operation of the stepper motor;
• determining a second value of power transferred to the stepper motor during a second operation of the stepper motor;
• determining a load angle of power delivered by the stepper motor during the first operation and second operation of the stepper motor based on the first value, the second value, and a stall power;
• and
• comparing the load angle to a stall threshold to detect a stall of the stepper motor.