Class drivers: skip and account the SS endpoint companion descriptor in every descriptor walk (hid, midi, midi2, ecm_rndis, printer, mtp, usbtmc), via a shared usbd_skip_ss_ep_companion() helper in usbd_pvt.h (cdc/ncm already handled; vendor/dfu naturally tolerant). usbtmc buffer grows to 1024 at SS to satisfy its packet-multiple assert. bth/audio/video are left FS/HS-only (ISO-centric; ISO is unsupported on the CH569 dcd). usbd.h: new SS template macros TUD_HID_SS_DESCRIPTOR(+INOUT), TUD_MIDI_SS_DESCRIPTOR (+ DESC_EP_SS part), TUD_MIDI2_DESC_ALT1_EP_SS, TUD_PRINTER_SS_DESCRIPTOR, TUD_MTP_SS_DESCRIPTOR, TUD_USBTMC_BULK_SS_DESCRIPTORS/INT_SS_DESCRIPTOR, with _SS_DESC_LEN counterparts (bulk endpoints hardcode 1024, companion after every EP). Examples: 17 bulk/interrupt examples gain the full SS descriptor set (EP0 512/64 clamp, SS device descriptor bcdUSB 3.20 mps0=2^9, SS config with companions, BOS caps, speed-switched callbacks): cdc_dual_ports, cdc_msc_freertos, dfu, dfu_runtime, dynamic_configuration, hid_boot_interface, hid_composite(+freertos), hid_generic_inout, hid_multiple_interface, midi_test(+freertos), midi2_device, msc_dual_lun, mtp, printer_to_cdc, usbtmc, webusb_serial. msc_dual_lun is un-skipped for CH569 using read-only flash disks (16KB RAM can't hold two 8KB RAM disks, same as ch32v10x/v20x boards). Validation: full example sweep green for hydrausb3_v1 (SPEED=super, 19 device ELFs) and raspberry_pi_pico; wTotalLength == sizeof() verified for every SS configuration array in the built ELFs; ceedling 65/65; pre-commit clean; code-size delta +0.0% on rp2040 (SS code folds out on non-SS builds). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_019MRGjBT2NBkCoWwyDT4LaE
MIDI 2.0 Song Sender
USB MIDI 2.0 Device example that plays "Twinkle Twinkle Little Star" using native UMP (Universal MIDI Packet) format with full MIDI 2.0 expression.
MIDI 2.0 Features Demonstrated
- 16-bit Velocity (vs 7-bit MIDI 1.0)
- 32-bit Control Change values
- 32-bit Pitch Bend (vs 14-bit MIDI 1.0)
- 32-bit Channel Pressure (Aftertouch)
- 32-bit Poly Pressure (Per-Note Aftertouch)
- Per-Note Management (MIDI 2.0 exclusive)
- Program Change with Bank Select
- JR Timestamps
USB Descriptors
The device exposes both USB-MIDI 1.0 (Alt Setting 0) and USB-MIDI 2.0 (Alt Setting 1) as required by the USB-MIDI 2.0 specification. A MIDI 2.0 capable host (e.g. Windows MIDI Services) will select Alt Setting 1 for native UMP transport. Legacy hosts use Alt Setting 0 with automatic MIDI 1.0 fallback.
| Interface | Class driver |
|---|---|
| 0–1 | MIDI 2.0 (audio control + MIDI streaming) |
Configuration
Notable tusb_config.h settings:
#define CFG_TUD_MIDI2 1
Building
CMake:
mkdir build && cd build
cmake -DBOARD=raspberry_pi_pico ..
cmake --build .
Make:
make BOARD=raspberry_pi_pico all
Testing
Linux:
aseqdump -p "MIDI 2.0 Device"
Windows (MIDI 2.0 native):
midi endpoint list
midi endpoint monitor
Song Data
Twinkle Twinkle Little Star in C major, 120 BPM. Six phrases with dynamic shaping (pp to ff crescendo and back), pitch bend vibrato on sustained notes, and channel/poly pressure for expression. All values use genuine MIDI 2.0 resolution with no 7-bit equivalent.