Wooden Touch Piano

Touch piano that can play a full octave of notes, without any moving keys! The notes are played using just the touch of your fingers on conductive paint keys. Play any tunes you want using the power of Arduino and Circuit Python!

• Plywood- 3/8 inch or 1/2 inch
• Plywood- 1/8 inch
• Hamburger Speaker
• Arduino Nano rp2040 connect
• breadboard - solder or solderless
• any wire, preferably small, about 10 pieces
• conductive paint (or foil)
• any color paint of your choosing
• battery pack with two usb ports
• micro usb cables (should come with speaker)
• mpr121 touch pad and stemma qt cable

The size of the piano board does not have to be exact and can be any size you want, minimum of 8 inches tall and 10 inches long to contain the electronics on the back.

For mine, i made it 21 inches long and 9 inches tall. Using 3/8 inch plywood, i cut out this rectangle on the miter saw.

I created a box 7 inches by 6 inches by 1.5 inches to hide and protect the electronics

The conductive keys are connected to the touch pad through wires, this is is done by drilling holes through the wood. Use whatever holes are just big enough to snake the wire through.

These holes should be spaced out evenly, as they will be in the location of each piano key.

A two inch hole is also drilled, and can be placed where ever the speaker is desired to be located.

If you would like handles to hold the piano from the sides, i found that and inch diameter hole works for most hand sizes, and anywhere from 4.5 to 5.5 inches should be long enough. be sure to leave two inches along the entire bottom edge of the piano for space for the keys.

Take your arduino with circuit python, and install the code attached. Plug the stemma qt cable into the touch pad and place the pins into the correct spots on the board.

Snake the wires through the holes you have drilled, securing them with hot glue.

Speaker can be attached using hot glue

Then solder these to the touch pad, 0-7, making sure to do them in order, from left to right, 0 to 7.

The speaker jack wire should be cut and stripped, using the green wire as ground and red wire as power, soldering them to the bread board as well.

The power bank can be attached however you would like, for simplicity and removability i used velcro command strips.

Paint a 2 by 2 inch square using the conductive paint, being sure to cover the wire that is sticking out from the holes you drilled.

IMPORTANT: It is also imperative to include a gap between the keys that is free of conductive paint that way each key can send a signal and operate correctly. If any of the keys are touching or connected by even a small amount of paint, the notes will not play correctly.

Sanding around the handles is recommended for comfort

This is also true with making sure the wire is in contact with the painted surface. The conductive paint may require more than one coat to ensure effectiveness. The remaining wood can be painted in any color.

Box can be assembled using super glue or wood glue, sealing the electronics. Small cuts may need to be made in these pieces to allow for wires to pass through.