Chris,

For the examples, I simply used the timers overflow to TOGGLE a pin, so the duty cycle is always 50%. But then, it's just an example. If you increase the frequency of the timer Overflows, either by reducing the prescaler, or by re-loading the timer on each interrupt, or both, you can control the duty cycle within the interrupt handler. By incrementing a variable you can have it turn on for 10 interrupts and off for 246, or whatever resolution you want.
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