Drops of Jupiter by the Common Tones of Boston College Capacitive Touch Board

For my Physical Computing course Make Art project, I made my own take on the DJ board we constructed in class. I took vocal tracks from my a cappella group that I recorded and then mixed in the studio, and made a board that plays each when a person's photo is touched.

Raspberry Pi Pico W board, small speaker (mine has a stereo jack), MPR121 Capacitive Touch Sensor, MicroSD SPI reader, conductive copper tape, purple & pink 1/8" acrylic, 12 alligator to alligator wires, breadboard, jumper wires.

First, we recorded all of the tracks in the studio. We saved them as mono tracks in .wav file format. This entire process and mixing took well over twenty hours but the final product is awesome!

As Publicity Director of the group, I then designed our single cover to be released on all streaming platforms. For this project, I had it printed as a 12" x 12" printout on C2S thick & glossy paper at Eagle Print for only $1. This served as my board and it's where I added the copper tape. I placed the copper tape on 12 of our members whose tracks I planned to use for this piece. Each piece of tape goes to the edge of the board to make it easier to wire after.

Attached is the code to mount the SD card with the song files to the board. Beneath it is the code that loads the .wav files into an array that calls each file depending on the touchpad activated. There is optional code that can be uncommented, which allows for an audio mixer to be used and tracks can be played simultaneously – it can't be used on all 12 of my tracks because the files are well over four minutes and even in their most condensed form (8000 Hz) they are too dense, but it does work for several which can be seen here. This program is the third code file.

This is the hardest part of the process for me. Attaching the speaker jumper wires, the microSD card reader, and the MPR121 Capacitive Touch Sensor can be done as pictured above. The pinout numbers can be found in the code, and I recommend checking out this site for an extensive diagram.

For cosmetic purposes, I also took advantage of the laser cutter. I created a box out of 1/8" pink and purple acrylic for my Pico W board and some of the wires. I also made a QR code of our song on Spotify to give the board some more structure and to add another fun interactive element. Both of the patterns are pictured and so is the final product.

Demo can be found here. Explanation of the parts can be found here.