[Ralph] used a 44.2 MHz can oscillator and set the device to use an external clock. He tested with a bit ... We’ve covered pushing a 20MHz AVR to 30MHz before, but that’s a little less ratio ...

AVR chips can use external clocks like a crystal oscillator ... Now that we have a divided clock source for the counter, and a target number of 15,625 cycles to watch for thanks to the math ...