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iii

PRELIMINARY: we’re approaching version 1.0.0. some features may change before then!

An evolution of capabilities for monome grid and arc, where an interactive scripting environment runs on the device itself.

  • scripting is in Lua (which is familiar to norns and crow)
  • scripts can be uploaded and stored, to be executed on startup
  • in addition to USB-TTY access to the scripting REPL, the device enumerates as USB-MIDI and provides scripting control over all MIDI communication
  • Lua libraries are provided for time-based operations (metros, measurement) and writing arbitrary data to the internal flash (ie: presets or stored sequences)

why do this?

The grid was originally conceived of as “doing nothing by itself” without being connected to a computer running a program. Now, the tiny computer inside the grid (RP2040) is capable enough of doing some interesting things. We’re hoping this means in some cases simply requiring less complexity (as in, a specialized eurorack module or DAW plugin or tricky command line framework). It also provides the possibility to connect to less-general-purpose computers (like phones) who prefer MIDI.

That said, the original method of interfacing via norns or serialosc (and any of the various languages and environments) is a fundamentally excellent approach. iii fills a small gap.

The new firmware is capable of toggling between iii and monome/serial modes.

compatibility

grid – editions

  • yes: 2022 and later grids (includes grids one and zero)
  • no: 2020-2021 grids use different microcontroller, hence cannot use this firmware. (they are, however, mechanically compatible so we are considering a PCB upgrade. TBA.)
  • no: all other grids use an FTDI USB Serial chip which means they can’t do USB-MIDI.

arc – editions

  • yes: 2025. has pushbutton.
  • no: everything else

firmwares

Note: arc ships with iii support. This process is not needed.

  • Download the most recent firmware for your specific device (Note that grids from 2022 have a different LED driver and hence require a different firmware. Identify the PCB revision by checking the date on the corner).
  • Remove the bottom screws.
  • Locate the golden pushbutton near the USB port. Hold it down while connecting the grid to a computer. This will start the device in bootloader mode.
  • A USB drive will enumerate. Download the appropriate firmware listed below and copy the file to this drive. The drive will unmount immediately upon copying the file (on macOS this may cause a benign alert).
  • Disconnect and put the screws back on (make sure to place the spacers first).

For firmware updates you can use the diii command ^^b to reboot the device into bootloader mode without opening the unit again.

modes

The “mode” is indicated by the startup light pattern.

  • particles: this is standard monome/serial mode, compatible with norns, serialosc, ansible, etc.
  • plasma: iii mode with a blank script.
  • something else: previously uploaded iii script.

To change the mode, while powering up the device hold down

  • grid: key 1,1 (top left)
  • arc: there’s only one key

To force-clear a script, switch into iii mode while holding down the key for two full seconds. (This may be helpful for debugging a locked-up script).

diii

A terminal text interface for iii devices, based on druid. Send commands, get text feedback, and upload scripts. See the source here.

install

Requires python and is installable via pip:

sudo pip3 install monome-diii

(For extended install instructions see druid’s install guide and remember to replace monome-druid with monome-diii).

run

For ease of managing scripts, navigate to the folder with your iii scripts ie:

cd ~/iii

Type diii in a terminal.

If things are working, it will report your device connected.
A few quick commands:

^^p         print script
^^c         clear script
^^z         reboot script
^^r         reboot device
^^b         reboot into bootloader mode

To upload a script:

u step.lua

To re-upload the same script, you can just execute u.

All other commands will be passed to the device’s Lua environment and any results will be printed.

To quit, execute q or CTRL-C.

writing scripts

See the repository for a few example scripts. This is also where discussion happens.

There is preliminary documentation on the README. We’ll move it here with examples and studies once the feature set is finalized.

library

arc

  • cycles - rotating midi cc with friction
  • erosion - four by four meta cc with interpolation and scene recall
  • snows - very slow asynchronous arpeggiator