# gbmUSBdevice

**Repository Path**: qq2524/gbmUSBdevice

## Basic Information

- **Project Name**: gbmUSBdevice
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-01-27
- **Last Updated**: 2026-01-27

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README


# gbmUSBdevice

A compact, simple, HAL-free USB device stack for easy creation of composite devices with STM32 MCUs.

Supported MCUs: STM32: F0x2, F103, L0, L4, F4 (OTG FS only), G0B1, H5x3, L5, U0x3, U535..585, C071.
Planned support: STM32U59x and above, STM32H7, CH32X03x.

Supported USB classes: CDC ACM (VCP), Printer, HID.
Planned: MSC BOT SCSI.

## Quick start using STM32CubeIDE

Out-of-the-box demos are currently available for STM32F0x2, F103, F401, G0B1, L4, H503/523/533, U083, U535/545, U575, C071. The demos uses pure event-driven approach with software-generated interrupts.
Example code for other MCUs as well as more conventional, event loop-based version of demo will be added soon.
By default, the example code creates a composite device made of generic text printer and two VCPs (only one VCP on F4 series due to only 3 application endpoints available in its USB OTG FS peripheral).
The composite device demo compiles to little over 5 kB with `-Os` option.
To use single VCOM (non-composite) demo, define the SIMPLE_CDC symbol in C Compiler preprocessor settings and set CDC_CHANNELS in 'usb_dev_config.h' to 1.

To compile and run the example using STM32CubeIDE:

- Download or clone the https://github.com/gbm-ii/gbmUSBdevice and https://github.com/gbm-ii/STM32_Inc repositories to your computer.
- Create a *New STM32 project* (STM32Cube type) for your MCU model. Do not change any settings; just generate code for the default configuration.
- Copy or link the `gbmUSBdevice` folder to include it in your project. Set the folder as source folder
 (right click on the folder name, *Properties - C/C++ Build* - uncheck *Exclude resource from build*).
- Copy or link the `STM32_Inc` folder to your project.
- Remove or rename the `main()` function in CubeMX-generated `main.c` file - `main()` from gbmUSBdevice example will be used instead of it.
- Add the `gbmUSBdevice/Example/Inc/<MCU_series>`, `gbmUSBdevice/USBdev/Inc` and `STM32_Inc` folders to the inlcude path; they should appear in the include path in exactly that order.

To see the demo in action:

- Connect the MCU's USB interface to a PC.
- Open the terminal sessions for the VCPs (TeraTerm seems to be good choice for Windows); once connected, the demo displays prompt with the VCOM logical number in a terminal window.
- The text typed in a terminal window is echoed. The text printed to the printer is displayed in VCOM0 terminal window.

Composite device configuration may be changed by editing `usb_dev_config.h` file. Newly added HID keyboard demo was tested on U0, U545, H5x3 and F401.

## Using gbmUSBdevice with HAL & CubeMX-generated code

Before calling `USBapp_Init()`:
- MCU and USB clocking must be set properly. This may be achieved using CubeMX-generated routine, replacing the `ClockSetup()` supplied with the examples. USB clock must be generated using:
	- PLL fed by HSE (all STM32; the only option for F1, F4)
	- HSI48 synchronized via CRS to USB SOF (F0x2, G0B1, L0, L4 excluding L47x, L5, U5, H5, H7)
	- PLL fed by HSI synchronized to LSE (STM32L47x, esp. Nucleo-L476 board)
- USB peripheral pins must be configured properly and the USB module must be activated. 
 In the examples it is done by `USBhwSetup()`. The replacement code may be generated by CubeMX if USB module is activated in device mode without selecting any USB-related middleware.
 
 ## CDC ACM (VCP) implementation
 
The Virtual COM port is meant to be compatible with CDC 1.2 ACM (no AT commands) specification, supporting the Set_Line_Coding, Set_Control_Line_State, Get_Line_Coding requests
and Serial_State notification.

## Printer

If enabled in `usb_dev_config.h`, Generic Text Printer device is created, which is recognized and handled by Windows without a need for a driver. 

## HID example

The HID example implements a keyboard device using one button/key and one LED. The hardware connection must be visible in the main file.
The example code for selected STM32 models uses Nucleo, F103 BluePill(Plus) or F4x1 BlackPill board button and LED. Once connected to a PC, the LED serves as ScrollLock indicator
and pressing a button causes the asterisk character to be input to the host computer.