I have made a basic PC fan controller with a thermistor and a n-MOSFET for driving the fan.
But the low default Arduino freqency creates a loud buzz from the fan. This is even more noticable than normal as to get an accurate RPM I turn the fan on full for 100ms while counting the tach.
So how can I change the frequency to something greater than 20kHz (human hearing limit)?
Also I am using the 16-bit PWM pin.