CHOMPI firmwares • one at a time

Feed the CHOMPI

Send a firmware over USB, keep it in one of the launcher's fifteen slots, and start it right away. Send to the same slot again and the new version replaces the old one.

This builds on the multi-firmware launcher by @sfaber02, which does the hard part of running several firmwares from one card. Firmware upload over USB is part of it since launcher v1.1.

  • 4 steps
  • one firmware at a time
  • Chrome or Edge
First time? Set up the card
  1. Back up your SD card: copy everything on it to your computer.
  2. Download chompi-multi-firmware-card.zip from the latest launcher release and unzip it.
  3. Format a microSD card as FAT32 (32 GB or smaller).
  4. Copy everything inside chompi-multi-firmware-card/ to the top level of the card.
  5. Put the card in CHOMPI and switch it on. The first start shows a rainbow while the launcher is installed, then the picker: key 1 TAPE, key 2 TEMPO, key 3 WAVE, key 15 USB storage.
  6. Plug CHOMPI into this computer and continue below.

  1. 1Connectnot connected

    Turn CHOMPI on with the launcher showing, plug it into this computer, then connect. Your browser will ask to allow MIDI; say yes. After that, this page connects by itself whenever it opens.

  2. 2Choose a firmware

    Drop a .bin here, or

    Or send one of the firmwares from the launcher v1.1 release card:

  3. 3Pick a slot and a name

    Press a key on the CHOMPI below. Whatever is in that slot now will be replaced.

    Not connected yet.

    The file will be called NN_NAME.bin. Use A–Z, 0–9, - and _.

  4. 4Send it

    CHOMPI's keys fill cyan as the firmware arrives and amber while it's written to the card. Then it starts.

Message log