SoftPWM, written by Brett Hagman, can create additional PWM outputs on any pin. The signal frequency is relatively slow (default 30 Hz), which is mostly useful for controlling the brightness of LEDs.

Download: SoftPWM.zip - Modified to work with Teensy 2.0

Hardware Requirements

SoftPWM can control up to 16 pins. Any digital pin may be used.

TODO: photo: board with 5 RGB LEDs

SoftPWM is compatible with Teensy 2.0 and Teensy++ 1.0 & 2.0.

TODO: table showing which pins are no longer available as normal PWM. Teensy 2.0: pins 10 & 12. Teensy++ 1.0: pins 1 & 24. Teensy++ 2.0: pins 1 & 24.

Basic Usage

TODO: write this

Example Program

TODO:

CPU Usage & Interrupt Latency

SoftPWM uses a timer and interrupt routine, which consumes considerable CPU time.

TODO: actually measure CPU usage (maybe try changing the number of channels...)

Latency sensitive libraries, like Servo and NewSoftSerial, will likely be disrupted by SoftPWM.

More Details

Please refer to the official SoftPWM documentation for more details.