representation of the TinyUSB stack.

Device Stack

Supports multiple device configurations by dynamically changing usb descriptors. Low power functions such like suspend, resume, and remote wakeup. Following device classes are supported:

  • Audio Class 2.0 (UAC2)

  • Bluetooth Host Controller Interface (BTH HCI)

  • Communication Class (CDC)

  • Device Firmware Update (DFU): DFU mode (WIP) and Runtinme

  • Human Interface Device (HID): Generic (In & Out), Keyboard, Mouse, Gamepad etc …

  • Mass Storage Class (MSC): with multiple LUNs

  • Musical Instrument Digital Interface (MIDI)

  • Network with RNDIS, CDC-ECM (work in progress)

  • USB Test and Measurement Class (USBTMC)

  • Vendor-specific class support with generic In & Out endpoints. Can be used with MS OS 2.0 compatible descriptor to load winUSB driver without INF file.

  • WebUSB with vendor-specific class

If you have special need, usbd_app_driver_get_cb() can be used to write your own class driver without modifying the stack. Here is how RPi team add their reset interface [raspberrypi/pico-sdk#197](

Host Stack

  • Human Interface Device (HID): Keyboard, Mouse, Generic

  • Mass Storage Class (MSC)

  • Hub currently only supports 1 level of hub (due to my laziness)

OS Abstraction layer

TinyUSB is completely thread-safe by pushing all ISR events into a central queue, then process it later in the non-ISR context task function. It also uses semaphore/mutex to access shared resources such as CDC FIFO. Therefore the stack needs to use some of OS’s basic APIs. Following OSes are already supported out of the box.


All TinyUSB sources in the src folder are licensed under MIT license. However, each file can be individually licensed especially those in lib and hw/mcu folder. Please make sure you understand all the license term for files you use in your project.