I was a mentor for MakerBay and want to document here the project from my student:

The goal is to building and designing an functioning electric piano with the microcontroller Arduino.

Ever since I started learning piano about 8 years ago... my friend started to make music using his computer, I started started to become a little bit more interested in making some music of my own. However when I come up with some chords or melodies, I am unable to play and record it properly on Logic Pro (in the software instrument where I can then edit it afterwards); as such, I end up trying to play it on my piano. Except, if I could have a portable electric piano, I would be able to jot my ideas down on the go, and be able to record it easily ...

This task is highly challenging as it requires the creator to be pretty well versed in electronics, be creative, know coding ... Some more specifics are having the ability to design a functioning piano, create an electrical circuit, and create the product using “final product” type materials.

Supplies

3D printer
with filament in two colors (classic is black and white)
breadboard (size depends on the amount of keys you want to have)
buttons for arduino (amount is the same as the amount of keys)
arduino microcontroller
2-AAA battery holder
speaker
wire
sandpaper
wood
drill

Autodesk Fusion 360 for Design
Automaker from Robox for 3D printing
Audio will be programmed with this library: https://github.com/bhagman/Tone/blob/master/README.md

Research:

Step 1: Design the Instrument

Make some initial sketches. They can be done on the computer (with Autodesk Fusion 360 a 3D CAD, CAM, and CAE software) or/and also with pen and paper. The size of the instrument depends on the amount of keys you want to have. If you need to be ready on time you should decide at this point how many functions you want to have because every function will need time. (for example: recording your music, power from battery or power from cable, an external Audio Jack to connect all kind of speaker or just one fixed speaker, just white or also black keys)

Step 2: Coding

The Tone library allows to play tones on a speaker (obviously^^).

The biggest effort was to make playing 3 tones together possible.

Micro Electric Piano.ino
Download

Step 3: Building the Circuit

Please see this to understand how your breadboard works/looks from the inside.

Step 4: 3D Printing

You can use a software like Automaker from Robox to design the parts and send the command to the printer. We printed 3 parts. One for the black buttons and two for the white (or here grey).