Firmware

The firmware is the program that runs on the RP2040. Once it's installed, the pad shows up to your computer as a plain USB keyboard, no drivers or extra software needed. Each button or contact pad simply types a key.

What it does

When you press a button (or bridge a contact pad), the pad sends a key press:

Input	Key sent
Up	Arrow Up
Down	Arrow Down
Left	Arrow Left
Right	Arrow Right
Plus (+)	Enter
Minus (−)	Escape

These are the keys Stepmania (and most rhythm games) use by default, so the pad works out of the box.

Get the firmware

The easy option is the pre-compiled file, a single .uf2 you drag onto the board, no tools required.

• Download the pre-compiled .uf2 — recommended.
• Firmware source code (repo/firmware/) — if you want to read or change it.

Install it

1. Unplug the pad from your computer.
2. Hold down the BOOTSEL button on the RP2040, and while holding it, plug the pad back into your computer.
3. The pad mounts as a USB drive. You can let go of the button now.
4. Drag the .uf2 file onto that drive.

The pad reboots automatically and the drive disappears, that's normal, it means the firmware installed. It's now running as a keyboard.

Test it

Press any button, or bridge two contact pads together (a strip of aluminum foil works well), and check that the matching key registers. The keyboard tester site is a quick way to see your presses live in the browser.

Build it yourself (optional)

The source is a PlatformIO project for the Waveshare RP2040-Zero. With PlatformIO installed, open the firmware/ folder and run:

pio run            # compile
pio run -t upload  # compile and flash a connected board

Compiling also produces a fresh stepminia.uf2 you can install by hand using the steps above.