Infrared Controlled Wah-Wah – Big Picture

The goal of this project was to build and program a wah-wah guitar effect pedal that is controlled through an infrared sensor to detect hand motion and vary the frequency of a guitar signal based on distance from the sensor.  Traditional wah-wah pedals are controlled via a potentiometer that varies the frequency response of the guitar creating a vocal wah wah sound effect. For this project the potentiometer was replaced with an LDR ( light dependent resistor), which varies resistance based on the amount of light detected.  The LDR was coupled to an LED with heat-shrink tubing to directly vary the amount of resistance based on the brightness of the LED. The LED is controlled with the atmega328pb microcontroller using ADC and PWM. The project was successful and resulted in an effective wah-wah guitar effect that is controlled through hand  movement. Control through the distance sensor allows for unique and expressive sounds based on the motion that the IR sensor detects. The sounds range from smooth crescendoing wah, to a fast stuttering effect when the hand is waved in successive motion over the sensor.