PWM - Pulse-width Modulation

Pulse-width modulation creates a rectangular wave signal that is commonly used for dimming or blinking an LED, control a display backlight or the speed of a motor (e.g. a fan).

Note that the outputs are only useful as control signals, not to actually drive a motor.

The PWM controller that has outputs available on the Raspberry Pi header (pwm@7e20c000) has two independent channels. The output of the first can be routed to GPIO 12 or GPIO 18, the second's output to GPIO 13 or GPIO 19.