MM00

ModMIDI

ModMIDI is a modular MIDI hardware and software project. This repository brings the base board, pad shield, extension board, and shared Arduino library together in one monorepo.

Current state: the KiCad source projects and PlatformIO configuration are present, but there is no board firmware or generated hardware PDF yet. Firmware and PDFs will be added/generated later; the current projects are not yet ready for a firmware build or hardware release.

Repository map

The MIDIUSB fork is maintained as a separate repository and is not nested in this monorepo. PlatformIO obtains it through the library dependency declaration; users do not need to clone the sibling repository separately.

Prerequisites

• KiCad 9.x to open all hardware projects. MM00 uses KiCad 9-format files; MM01 and EX08 use KiCad 8-format files.
• PlatformIO Core for future firmware builds. Install PlatformIO yourself; this repository does not provide CI builds.
• Network access on the first PlatformIO dependency resolution to retrieve external libraries.

MM01's project includes its custom TL1105 footprint and the referenced STEP model using project-relative paths. A standard KiCad installation is still required for standard libraries and models. The included E-Switch asset did not come with license/provenance information; confirm its redistribution terms before publishing the repository publicly.

Open the hardware

Open each KiCad project file:

• MM00 base board
• MM01 4×4 pad shield
• EX08 extension board

The editable KiCad projects are the hardware source of truth. PDFs, Gerbers, and BOMs are generated manually and are not produced by a script in this repository.

Board PDFs

No PDFs are included yet. Adam will generate and add them manually under each board's hardware/output/ directory. These links show the planned locations and will become available once the files are generated:

• MM00: boards/MM00/hardware/output/MM00-schematic.pdf — pending
• MM01: boards/MM01/hardware/output/MM01-schematic.pdf — pending
• EX08: boards/EX08/hardware/output/EX08-schematic.pdf — pending

Gerbers and BOMs may also be added manually under the same hardware/output/ directories. Intended output files are not ignored by the repository rules.

Firmware

MM00 is the base board with the STM32F103C8 controller. MM01 is a shield driven by the MM00 controller; EX08 is passive and has no firmware. The per-board PlatformIO configurations select the STM32 Arduino target and link the local modmidi-arduino/ library. USB support flags are included for USBLibrarySTM32/MIDIUSB.

For example, the MM00 configuration is in boards/MM00/software/platformio.ini:

cd boards/MM00/software
pio run

MM01 has a corresponding configuration under boards/MM01/software/. These commands cannot build firmware yet: neither software directory contains source files. Adam plans to add firmware later. No upload protocol is configured; confirm the actual programmer/bootloader and MM00's 16 MHz HSE clock/USB setup before attempting to flash. EX08 has no software/ directory.

The board projects reference the library locally with symlink://../../../modmidi-arduino. Do not install the repository root as a PlatformIO library URL; the library's library.json is inside the modmidi-arduino/ subdirectory. PlatformIO fetches the declared USB dependencies, including the adampisula/MIDIUSB branch 1.0.5 and levi--g/USBLibrarySTM32 ~1.0.1.

See the modmidi-arduino README for API details and current implementation notes.

Licensing

First-party ModMIDI code, documentation, and hardware are provided under the MIT License; see LICENSE. Third-party dependencies and assets retain their own licenses and are not relicensed by the root MIT license. In particular, MIDIUSB is LGPL-2.1 and USBLibrarySTM32 is LGPL-3.0-or-later. Redistribution terms for the bundled E-Switch footprint/model still need confirmation before a public push.