esp32-s3-devkitc-usb-midi2

midi2cpp | Device MIDI 2.0

ESP32-S3-DevKitC-1

Full-spec USB MIDI 2.0 device on the ESP32-S3-DevKitC-1 (Xtensa LX7, USB-OTG internal PHY at full-speed 12 Mbps). Headless single-file showcase of every MIDI 2.0 message category beyond MIDI 1.0. ESP-IDF v5.4 build, no Arduino IDE.

USB identity

Field	Value
VID:PID	cafe:4090 (development-only)
Product	ESP32S3DevKitC
Manufacturer	github.com/sauloverissimo

Build

Requires ESP-IDF v5.4+ with . $IDF_PATH/export.sh sourced, an ESP32-S3-DevKitC-1, two USB cables (left jack for UART + flash, right jack for native USB).

cd idf
./scripts/fetch_tinyusb.sh         # one-off, ~36 MB clone of TinyUSB upstream
. $IDF_PATH/export.sh
idf.py set-target esp32s3
idf.py build
idf.py -p /dev/ttyUSB0 flash monitor    # left jack (CP2102)

The left jack uses a CP2102 with real DTR / RTS, so esptool's auto-reset puts the S3 in download mode without a button press.

CP2102 not detected on Linux

Some DevKitC-1 v1.1 boards ship a CP2102N variant with idVendor=0x11ca, idProduct=0x0204, which the cp210x driver does not list by default. Force the bind once per kernel session:

echo "11ca 0204" | sudo tee /sys/bus/usb-serial/drivers/cp210x/new_id

Flash via the right jack (USB-Serial-JTAG)

The right jack exposes the S3 USB-Serial-JTAG ROM bootloader as /dev/ttyACM0 before the firmware claims it. Real DTR / RTS is fake on USB-Serial-JTAG, so a watchdog reset is required:

idf.py -p /dev/ttyACM0 flash
python -m esptool --chip esp32s3 -p /dev/ttyACM0 --after watchdog_reset run

To override TinyUSB with a local working copy: ln -sfn /path/to/your/tinyusb idf/external/tinyusb && idf.py reconfigure.

Hardware

Pin	Use
USB Port (right jack)	Native USB-OTG, MIDI 2.0 device interface
USB-to-UART (left jack)	Console stdio @ 115200 8N1 (showcase log)
GPIO48	On-board RGB LED (WS2812). Green = mounted, red = waiting for host. Override with -DLED_STRIP_GPIO=<n> for v1.0 boards (LED on GPIO38)
BOOT (GPIO0)	Hold during reset to enter download mode

Validation

lsusb | grep cafe:4090
amidi -l                        # IO  hw:N,1,0  Group 1 (Main)
PORT=$(aseqdump -l | grep -i ESP32S3DevKitC | awk '{print $1}' | tr -d ':')
timeout 30 aseqdump -p ${PORT}

Microsoft MIDI Services Console (Windows) shows ESP32S3DevKitC with Native data format = UMP, MIDI 2.0 Protocol = True.

Spec coverage

Tier A (full spec). The ESP32-S3's 512 KB SRAM (plus 8 MB PSRAM on R8 variants) 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. GPIO48 LED green.

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 (left jack) at 115200 8N1.

License

MIT, inherits parent midi2cpp LICENSE.