Ah - just read your reply in more detail. I think I will probably go for setting the timer to a constant rate of, say, 10Hz, then
changing my effective frequency by only responding every n interrupts, where n is a value received over the serial link.

This will make it easier to change the frequency than having to recalibrate the hardware timer each time. As long as the hardware timer is >= my max desired frequency, then by setting different values for n I should be able to get any frequency below.

Thanks,


Ben