For a while I couldn't see the Arduino microcontrollers that IMA gave us to serve as anything more than little science projects. Until I came across tiny piezoelectric speakers and the tone function. Normally these things are used to play a single tone in a particular rhythm to signal errors and the like, but by differentiating the pitches that it plays, one could turn it into an instrument.
The overall project was objectively simple: put a bunch of buttons on a circuit and add a speaker. Then, map each button to a number using an array. The number is the frequency of the note that I want a certain button to play, i.e., middle C is 262 Hz. Back on the hardware side, each button required a different resistor so that the signals they sent back to the Arduino were unique. Changing and trying out different resistors on just eight separate buttons took a while, but in time I got it to work well enough, where the sound each button produces is clear enough to work as a makeshift keyboard. I then used a marker and index card to create the “keys” that would go over the electronics and serve as a larger platform for users to rest their fingers on.
From here, it should be possible to extrapolate the project and make a full size keyboard by simply adding more breadboards or even a custom soundboard, given one has enough individual resistors to uniquely identify all the buttons they want to use.
