I am trying to control a servo motor (link). It is a brushless DC motor with an interface similar to a stepper motor.
The motor rotates for a defined distance based on the number of pulses it receives from the
PWM. The speed is determined by the pulse frequency of the
PWM, like a stepper motor.
To control this motor I am using a microcontroller
STM32F407ZET6. I can easily change the frequency and Duty Cycle of PWM, but my question is the following:
How do I generate a fixed number of pulses in the PWM? For example, I want the PWM to send 1000 pulses at a certain time with a frequency of 20kHz and a Duty Cycle of 50%. 20kHz and 50% Duty Cycle are easy to define, but I can't determine how to generate the 1000 fixed pulses.
One of the solutions I tried was to connect the PWM back to a timer in counter mode and stop the PWM when the required number of pulses has been generated. But the number of pulses is not always fixed, sometimes ranging from 998 to 1005 (for example).
Is it possible to do this without the need for feedback?