A mechanical keyboard... but the OTHER type of "keyboard."
This DIY 3D printed monophonic (1 key at a time) keyboard uses 12 mechanical keyboard switches for piano keys. It is powered by an Arduino UNO and fitted with a speaker and a potentiometer to change between 3 octaves. Watch the video demo below to see how it sounds!
3D overview of the keyboard case. I printed using a .4mm nozzle and 20% infill. Supports are necessary for some parts but do not put too many. Printing took around 2 days to fully complete all parts but can be reduced signifcantly by reducing infill and lowering the thickness of the walls. Since the STL files were larger than my print area, I had to split the case into multiple parts.
First, gather all necessary parts before building. This includes the 3D printed case, keys and screws, 12 mechanical keyboard switches, 1 potentiometer, 1 speaker/piezo, a mini breadboard, and an Arduino Uno. Components are placed as shown in the second image.
Next, wire up the mechanical switches to the mini breadboard according to the circuit diagram in the next sections. Be sure to route the wire under and through the keycap holder prior to soldering.
Then, attach the piezo speaker and the potentiometer attached to the top of the case.
Lastly, screw in piano keys on top of the mechanical switches and cover the top case.
Done!
Refer to the following circuit diagram for information on how to wire components together.