monome / Whimsical RapsEurorack & modular
Scriptable USB-to-CV Lua module (discontinued)
crow is a 2HP Eurorack module from monome and Whimsical Raps with two CV inputs, four 16-bit CV outputs, a USB port and an ii/i2c connection on the rear. It runs a Lua scripting environment on an STM32F722 microcontroller and stores a complete script, so it keeps responding to CV and ii messages with no computer attached. Scripts are loaded from norns, from a computer through the druid terminal tool, or from Max and Max for Live.
monome's site lists crow as discontinued as of October 2025; the firmware repository still receives commits. Firmware is open (GPL-3.0) and community forks add features, so read each fork's own docs before swapping builds. Update with druid (`druid firmware`), the fledge script on norns, or a manual DFU flash. Lua scripts run on stock firmware and are not catalogued.
Official open-source crow firmware: the Lua scripting runtime, ASL envelope and LFO engine, i2c leader and follower, and USB text interface for the 2HP module.
by monome, Whimsical Raps
evnoj's crow fork with extra output modes (including a "spinner" ramp oscillator for circular parameters), clock additions and TELEX / TXi commands. Built from source.
by Evan Johnson
| Version | Date |
|---|---|
| main-ev (branch head) | 2026-06-07 |
Unofficial crow fork that merges the i2c2midi library into the firmware itself, with chord and note commands plus first-pass MIDI getters. One pre-release build was published in November 2023.
by eethann
| Version | Date | Notes |
|---|---|---|
| 4.1.0-i2c2midi-rc1 | 2023-11-07 | GitHub pre-release. |
monome's Python terminal REPL for crow: send Lua, upload scripts, read output, and update crow firmware with `druid firmware`.
by monome
Browser-based Lua editor and REPL for crow and crow-like devices over Web Serial, with a Monaco editor beside the output console, modelled on maiden. Chromium browsers only.
norns script that updates crow firmware: it checks for pip3 and Python modules, fetches the current crow firmware, activates the bootloader and flashes it.
by monome