Macropad Sequencer#

A minimal USB MIDI step sequencer that runs on the Adafruit Macropad written in Rust using Embassy.

This is more of a tech demo than anything else! I'm using it to mess around with ideas I have around structuring non-trivial Embassy apps and will probably come back and add more features whenever I need a break from life.

Quick demo of it in action:

https://github.com/user-attachments/assets/acf0101d-1b00-4f44-b153-62827f4cb186

Usage#

This isn't the ideal hardware interface for a step sequencer, but I've (mostly) done the best with what I have.

• Each key is a step in the sequence
• Press and release a key to toggle the step on and off
• Hold a single key down to change the note and velocity
• Hold down multiple keys to cycle between those notes

Flashing#

While holding down on the rotary encoder, press and release the reset button on the side. The macropad should show up as a USB mass storage device. You can then drag the uf2 file the releases page and reboot it.

For development, install elf2uf2-rs and do cargo run --release.

Future development#

I had to stop hacking on this before it completely consumed my life, but here's a few things I'd like to add:

• Swing
• "Gate" (percentage of step note is on)
• Menu scrolling to support more than 4 options per menu
• A little synth engine that uses the onboard speaker (need to make use of that second core!)
• More than 12 steps?