Arduino Basics: PWM Frequency The PWM frequencies in Arduino a pretty much set. You can’t really change them from the IDE. For example, pin 9 PWM frequency is set at 490Hz. Other pins have different frequencies, which are controlled by the Atmega 328P timers. You can change the pre-scaler for these timers and effectively change the frequency, but it can be a bit of a bother to look up the code. But, the good news is that there is a library, called PWM that let’s you change the frequency of the PWM pins in the IDE with the SetPinFrequencySafe() function. You can download this library here: https://code.google.com/archive/p/ard… The frequency counter I used in this video is from BangGood.com. It’s a kit, and it’s available here: Geekcreit® DIY Frequency Tester 1Hz-50MHz Crystal Counter — https://goo.gl/DCy9Pz
