Turn your bookshelf into a piano

Get the board

You'll also need kitchen foil, one jumper wire per book (female-to-male), tape, a good phone charger, and Chrome on Android, Windows or Mac.

Tape a wire to a strip of foil and slide it behind the book's spine. Glue it so it can't move.

One wire per book onto the touch pins: 4, 13, 14, 27, 32, 33, then 15, 2, 12. On an S3 board, pins 1 to 12. Any order works.

Plug the board into a laptop, open this page in Chrome, and press install.

Open this page in Chrome or Edge on a laptop or desktop to install.The installer needs a secure (https) page.

Only if you're adding more books.

Power the board from a charger. Open TapTune on your phone, tap Connect Bluetooth, then Setup, and touch each book when it asks.

Something not working?

Books play by themselves: Use a better charger. A cheap one made mine go crazy.
A book won't stop playing: The foil moved. Glue it down and tap lightly.
One tap plays two books: Move the foil strips further apart.
Touching my phone plays notes: Don't plug the board into the phone. Use Bluetooth.
The laptop can't find the board: Try another USB cable, or hold BOOT while plugging it in. On Windows the ₹349 board may need its CP210x or CH340 driver.
Book Piano doesn't show up in TapTune: Use Chrome, turn on Bluetooth and Location, and unplug the board for five seconds.

Prefer Arduino? The code is on GitHub. The ₹349 board's software is brand new; tell me how it goes.