[SOLVED] increase PWM frequency, without affecting timers (like millis)?

I can post code and schematic if need be (it is on my Github, actually), but here is my situation.

I am building a rackmount server enclosure, and i have a ventilation blower (12V, salvage from a camper furnace) that i am driving with a BTS7960 based motor driver, using arduino PWM from pin 6 on an arduino Mega2560. the idea is to ramp up the blower, based on internal temperature. it all works good when i tested it, but the PWM whine from the blower motor is fairly annoying. what would be the best way to increase the PWM frequency, above hearing ability, so it runs quieter? i found THIS, but it affects the on-board timers.

if that is not possible, are there any recomendations?

Right now the code is set to turn the blower on full, or off full, depending on temperature. this works, but i would rather have the blower ramp up if possible.

Thanks in advance for any help.


Each hardware Timer controls the PWM on two pins. If you choose a pin that is not used by Timer0 you can change the frequency without affecting millis()

Study the relevant Atmega datasheet for the details.