Chord Identifier

Video of the Chord Identifier Identifying Chords from Synthesized Instruments

A microphone collects audio data, the microcontroller interprets that data and displays any 3-note chord that it hears on the VGA monitor screen.

This video depicts my final project for my senior design class, ECE 4760. Musical notes are identified by their frequencies. A series of notes played at the same time create a chord. My lab partners and I aimed to identify any 3-note chord using a microphone and a microcontroller. The microphone collects audio data. Using a Sallen-Key Low Pass Filter we remove any extra audio data. The remaining data enters a Pico microcontroller which finds the three 'strongest' frequencies using a Fast Fourier Transform (FFT). After the three strongest frequencies are found, they are matched to the correct note. If the combination of all three notes is a valid chord, that chord is displayed on the VGA monitor screen. Our design can identify major, minor, augmented, diminished, and triad chords.

If you would like to learn more about this project, here is some documentation at a lower level describing how this system was implemented and tested.