HID Multiple Interfaces

A composite USB device with two separate HID interfaces — one keyboard and one mouse — each with its own report descriptor, endpoint, and interface string.

What it does

• Presents two independent HID interfaces: a keyboard (interface 0, "Keyboard Interface") and a mouse (interface 1, "Mouse Interface").
• Polls the board button every 10 ms:
  • Keyboard: while the button is held, sends the A keycode; releasing sends an empty report.
  • Mouse: while the button is held, moves diagonally (+5, +5).
• If the device is suspended, pressing the button issues a USB remote wakeup.
• The LED blinks to indicate USB state (250 ms not mounted, 1000 ms mounted, 2500 ms suspended).

USB Descriptors

Configuration

Notable tusb_config.h settings:

#define CFG_TUD_HID            2 // keyboard + mouse
#define CFG_TUD_HID_EP_BUFSIZE 8

Building

CMake:

mkdir build && cd build
cmake -DBOARD=raspberry_pi_pico ..
cmake --build .

Make:

make BOARD=raspberry_pi_pico all

Try it

After flashing, the board enumerates as two distinct HID devices, a keyboard and a mouse. Press and hold the button: the host receives repeated A key presses and the pointer drifts toward the bottom-right.