iii (arc)
monome's iii firmware for the 2025 arc, which has a pushbutton: standalone Lua scripts on the arc itself, USB-MIDI and a serial REPL, with a serialosc mode for use with norns, ansible and computers.
- Distribution
- Prebuilt image you flash yourself
- Requires stock
- 2025 arc (with pushbutton)
- License notes
- Docs state GPLv3 and LICENSE.txt is GPLv3 text; no per-file "or later" grants found.
- Source
- codeberg.org https://codeberg.org/tehn/iii
- Homepage
- monome.org https://monome.org/docs/iii/
- platform
- scripting
- usb-midi
Description
The 2025 arc ships with iii support, so it needs no separate install; this entry tracks the arc build that is published beside the grid builds in each iii release (iii-arc.uf2). Hold the key while powering up to return the arc to serialosc mode. Older arcs cannot run it; viii runs iii scripts in a browser against them instead. Example scripts named in the docs include cycles, erosion and snows.
Install notes
The UF2 is attached to each iii release; see the iii docs for entering the bootloader. The docs describe the diii browser tool for restarting a grid into it.
Version history
| Version | Date |
|---|---|
| v1.1.2 | 2026-04-18 |
| v1.1.1 | 2026-03-24 |
| v1.1.0 | 2026-03-22 |