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midi2cpp | Device MIDI 2.0

Waveshare RP2040 Pi Zero

Full-spec USB MIDI 2.0 device on the Waveshare RP2040 Pi Zero (compact 18.0 x 23.5 mm RP2040 board with USB-C). Headless single-file showcase of every MIDI 2.0 message category beyond MIDI 1.0. Pico SDK build, no Arduino IDE.

waveshare-rp2040-midi2 banner

USB identity

Field Value
VID:PID cafe:4072 (development-only)
Product RP2040PiZero
Manufacturer github.com/sauloverissimo

Build

Requires Pico SDK 2.x (with PICO_SDK_PATH exported), arm-none-eabi-gcc, CMake 3.14+.

cmake -B build         # first run fetches TinyUSB
cmake --build build -j

Pointing at a local TinyUSB checkout: cmake -B build -DPICO_TINYUSB_PATH=/path/to/tinyusb.

Flash

Hold BOOT, plug USB-C, drag build/waveshare-rp2040-midi2-showcase.uf2 to the mounted RPI-RP2 drive.

Hardware

Pin Use
USB-C MIDI 2.0 device (only USB function)
GP0 / GP1 UART TX/RX debug print @ 115200 8N1
GP16 On-board WS2812 RGB LED (not driven)
BOOT Hold while plugging USB-C to enter BOOTSEL

No on-board reset button on the standard model; power-cycle to reset.

Validation

lsusb | grep cafe:4072
amidi -l

Plug straight into a laptop running Microsoft MIDI Services Console for end-to-end MIDI 2.0 enumeration:

bench setup Microsoft MIDI Services Console

Spec coverage

Tier A (full spec). The RP2040's 264 KB SRAM affords the complete UMP + MIDI-CI surface.

UMP MT Spec Notes
0x0 Utility M2-104-UM §3 JR heartbeat 500 ms, Delta Clockstamp
0x4 MIDI 2.0 Channel Voice M2-104-UM §7 32-bit CCs, Per-Note family, Note Attribute, RPN/NRPN, Relative RPN/NRPN
0x3 SysEx7 M2-104-UM §7.7 up to 6 bytes per packet, auto-fragmented
0xD Flex Data M2-104-UM §10 Tempo, Time Sig, Key Sig, Metronome, Chord Name, Start/End of Clip
0xF UMP Stream M2-104-UM §11 full Endpoint + FB Discovery

MIDI-CI: Discovery + Profiles (1 custom registered) + Property Exchange (3 properties: static, dynamic, subscribable) + Process Inquiry, all via the m2ci Appendix E convenience responder.

Showcase

Always on while mounted: JR heartbeat (500 ms), UMP Stream + MIDI-CI Discovery responders, 1 custom Profile, 3 PE properties, Process Inquiry replies.

Per cycle (~22 s):

Scene Content MIDI 2.0 only because
A. Flex Data Tempo (120 BPM), Time Sig (4/4), Key Sig (C), Metronome, Chord Name (Cmaj7), Start of Clip MT 0xD + 0xF
B. Per-Note Sustained C4 with Per-Note Pitch Bend (5 Hz vibrato), Registered Per-Note Controller #7, Assignable Per-Note Controller #74, Per-Note Management Reset Per-Note family is MIDI 2.0 only
C. Resolution Chromatic walk C5→G#5 with 16-bit velocity ramp, 32-bit CC #74 sweep, 32-bit Pitch Bend, 32-bit Poly Pressure, 32-bit Channel Pressure MIDI 1.0 caps at 7/14-bit
D. Program + Bank Program Change with bank MSB/LSB in a single UMP MIDI 1.0 needs three messages
E. RPN/NRPN RPN 0/0, NRPN, Relative RPN (+delta), Relative NRPN (-delta) RPN/NRPN first-class + Relative
F. Note Attribute Note On with attribute_type=0x03 (pitch_7_9), E4 +50 cents Microtonal attribute
G. SysEx7 Universal SysEx Identity Reply, 12 bytes, auto-fragmented (Start + End) MT 0x3
H. Delta Clockstamp DCTPQ=480 + Delta Clockstamp=240 ticks MT 0x0 utility
I. PE Notify Broadcast OverlayRate change to subscribers (value increments per cycle) Property Exchange
J. End of Clip Sequencer End of Clip marker MT 0xF status 0x21

Every scene logs to UART (GP0). Windows MIDI Services Console captures live in monitor/.

License

MIT, inherits parent midi2cpp LICENSE.