Set up a timer that interrupts at your duty cycle (say 500us). Once that timer trips, set it up for another interrupt for 51582us-500us. This provides a total period of 51582us -> 19.5hz.
Set up a timer that interrupts at your duty cycle (say 500us). Once that timer trips, set it up for another interrupt for 51582us-500us. This provides a total period of 51582us -> 19.5hz.