Real-Time Audio processing Based on Arduino

The project is an experiment to illustrate that an Arduino can be used to create a real-time audio processing wherein the first set of examples alter an incoming audio signal to an audio output and the second set are outputted computed waveforms.

In the design, a capacitor is used to connect the audio input signal to the analog input 1 of the Arduino board. A DC offset is added to the audio signal by the 2 resistors and a trim pot while the audio effect are controlled using a potentiometer connected to analog input 0. The trim pot adjusts the DC offset value. An RLC filter is used to connect the PWM audio output on pin 11 to the audio output jack and an active PC speaker can be used to connect the output.

A constant offset has to be added to the signal by implementing a resistor divider since the analog-to-digital converter on the Arduino can measure only positive voltages. A positive and negative wave parts comprise a natural audio signal that results to electrical AC audio signal. The concept of the software includes a main loop and an interrupt function.

Rest of the project