HID Generic In/Out

A USB HID device that exchanges raw IN/OUT reports over a vendor-defined usage page, with no standard keyboard/mouse usage. It simply echoes back whatever the host sends.

What it does

• Presents one HID interface built from the generic in/out report descriptor template (vendor usage page), with both an IN and an OUT endpoint.
• Whenever the host sends data on the OUT endpoint (or via SET_REPORT), the device echoes the same bytes back to the host via tud_hid_report.
• The LED blinks to indicate USB state (250 ms not mounted, 1000 ms mounted, 2500 ms suspended).
• Because the reports carry no standard HID usage, the device is meant to be driven by a host-side tool rather than recognized as a keyboard/mouse. The example ships with hid_test.js (node-hid) and hid_test.py (Python hid) scripts to send and receive data.

USB Descriptors

Configuration

Notable tusb_config.h settings:

#define CFG_TUD_HID            1
#define CFG_TUD_HID_EP_BUFSIZE 64

Building

CMake:

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

Make:

make BOARD=raspberry_pi_pico all

Try it

After flashing, run the bundled host tool — node hid_test.js or python3 hid_test.py — to send a buffer to the device and observe the same data echoed back.