This project is a light controlled Theramin for the 4-chord enthusiast. It is based on Project 6 in the Arduino Starter Kit projects book and extended to be pitch focused rather than a continuous spectrum of frequencies.
This project uses a photoresistor, 2 buttons, a piezo, and a Potentiometer to create a Theramin which can play 4 chords (I - IV - V - vi) in any key. Changing the amount of light reaching the light sensor (by moving a hand up/down near it) controls pitch. The buttons control the arpeggiated chord that is played:
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- no buttons pressed: I chord
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- BUTTON1 pressed: V chord
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- BUTTON2 pressed: IV chord
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- both buttons pressed: vi chord
The potentiometer controls the key in half steps - 0 is A major -> 12 is G# major.
When the Arduino is first powered on, it enters a calibration phase for 5 seconds during which time the onboard LED will be on. To calibrate, move your hand near the light sensor in the range that you expect to use it.