Host: Device Info

Example source: examples/host/device_info

A USB host example that enumerates any attached device and prints its descriptor information over the debug UART. No class drivers are enabled — only the hub driver, so it works with any kind of device.

What it does

  • On mount of any device, fetches and prints the full device descriptor: VID/PID, USB version, device class/subclass/protocol, max packet size, bcdDevice, and number of configurations.

  • Reads and prints the manufacturer, product, and serial-number string descriptors (UTF-16 to UTF-8), falling back to a placeholder serial when none is present.

  • Blinks the board LED, with a faster pattern while no device is mounted.

  • Builds on either the bare main loop or a FreeRTOS task, depending on CFG_TUSB_OS.

Requirements

The board must support USB host mode (provide VBUS to the connected device); some boards need an external USB-A port / host adapter.

Configuration

Notable tusb_config.h settings:

#define CFG_TUH_ENABLED             1
#define CFG_TUH_HUB                 1
#define CFG_TUH_DEVICE_MAX          (3*CFG_TUH_HUB + 1)
#define CFG_TUH_ENUMERATION_BUFSIZE 256

Building

CMake:

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

Make:

make BOARD=raspberry_pi_pico all

How to use

Plug any USB device into the board’s USB host port. The debug UART prints the device’s ID vvvv:pppp, serial number, and the decoded device descriptor (a hub lets you attach several devices, each printed in turn). Unplugging the device prints a removal message.