Reduce PWM Frequency Arduino DUE
The Palatis Softpwm library can generate PWM on any digital pin with (almost) any frequency. Example for 25Hz:

#include &lt;SoftPWM.h&gt;
SOFTPWM_DEFINE_CHANNEL(0, DDRB, PORTB, PORTB2);  //Arduino pin 10
void setup() {
  // begin with 25Hz pwm frequency
  Palatis::SoftPWM.begin(25);
  Palatis::SoftPWM.set(0, value); // value is 0 to 255 just like normal Arduino analogWrite
}