Guitar tremolo pedal firmware for Microchip PIC16F684. Uses CCS C compiler.
Firmware operation based heavily on Electric Druid's VCLFO (http://www.electricdruid.net). Five DDS functions implemented: Sine, Ramp Up, Ramp Down, Square, and Triangle. PWM output controls an LED which modulates a photoresistor, which adjusts the gain of an op-amp.