TinyUSB

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Overview

TinyUSB

TinyUSB is an open-source cross-platform USB Host/Device stack for embedded systems. It’s designed for memory safety (no dynamic allocation) and thread safety (all interrupts deferred to non-ISR task functions). The stack emphasizes portability, small footprint, and real-time performance across 50+ MCU families.

Sponsors

TinyUSB’s continued development is made possible by its sponsors. If TinyUSB helps your products or projects, consider funding its development on GitHub Sponsors.

Platinum

Adafruit has backed TinyUSB since day one as its founding and sole Platinum sponsor. Buying their products directly funds the project’s development.

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Key Features

  • Thread-safe: USB interrupts deferred to task context

  • Memory-safe: No dynamic allocation, all buffers static

  • Portable: Supports 50+ MCU families

  • Comprehensive: Includes CDC, HID, MSC, Audio, and Host support

  • RTOS-friendly: Works with bare metal, FreeRTOS, RT-Thread, and Mynewt

stackup 
.
├── docs            # Documentation
├── examples        # Examples with make and cmake build system
├── hw
│   ├── bsp         # Supported boards source files
│   └── mcu         # Low level mcu core & peripheral drivers
├── lib             # Sources from 3rd party such as FreeRTOS, FatFs ...
├── src             # All sources files for TinyUSB stack itself.
├── test            # Tests: unit test, fuzzing, hardware test
└── tools           # Files used internally

Getting started

See the online documentation for information about using TinyUSB and how it is implemented.

Check out Getting Started guide for adding TinyUSB to your project or building the examples. If you are new to TinyUSB, we recommend starting with the cdc_msc example. There is a handful of Supported Boards that should work out of the box.

We use GitHub Discussions as our forum. It is a great place to ask questions and advice from the community or to discuss your TinyUSB-based projects.

For bugs and feature requests, please raise an issue and follow the templates there.

See Porting guide for adding support for new MCUs and boards.

Device Stack

Supports multiple device configurations by dynamically changing USB descriptors, low power functions such like suspend, resume, and remote wakeup. The following device classes are supported:

  • Audio Class 1.0/2.0 (UAC1/UAC2)

  • Bluetooth Host Controller Interface (BTH HCI)

  • Communication Device Class (CDC)

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

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

  • Printer class

  • Mass Storage Class (MSC): with multiple LUNs

  • Musical Instrument Digital Interface (MIDI)

  • Media Transfer Protocol (MTP/PTP)

  • Network with RNDIS, Ethernet Control Model (ECM), Network Control Model (NCM)

  • Test and Measurement Class (USBTMC)

  • Video class 1.5 (UVC): work in progress

  • 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 a special requirement, usbd_app_driver_get_cb() can be used to write your own class driver without modifying the stack. Here is how the RPi team added their reset interface raspberrypi/pico-sdk#197

Host Stack

  • Communication Device Class: CDC-ACM

  • Vendor serial over USB: FTDI, CP210x, CH34x, PL2303

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

  • Mass Storage Class (MSC)

  • Musical Instrument Digital Interface (MIDI)

  • Hub with multiple-level support

Similar to the Device Stack, if you have a special requirement, usbh_app_driver_get_cb() can be used to write your own class driver without modifying the stack.

Power Delivery Stack

  • Power Delivery 3.0 (PD3.0) with USB Type-C support (WIP)

  • Super early stage, only for testing purpose

  • Only support STM32 G4

OS Abstraction layer

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

  • No OS

  • FreeRTOS

  • RT-Thread: repo

  • Mynewt Due to the newt package build system, Mynewt examples are better to be on its own repo

Supported CPUs

Table Legend

✔

Supported

⚠

Partial support

✖

Not supported by hardware

[empty]

Unknown

Development Tools

The following tools are provided freely to support the development of the TinyUSB project:

Information

Project Info