some question about usb implementation for STM32F3

1. The STM32_USB_Device_Library that is shipped with STM32CubeMX only supports one configuration and one interface, therefore it's not suitable for composite device implementation. This limitation doesn't apply to the hardware itself, and it has enough endpoints and packet memory to support your application needs. There are commercial USB device drivers that support multiple interfaces, you can check the list 

http://www.st.com/en/embedded-software/stm32-3rd-party-embedded-software.html?querycriteria=productId=LN1900

2. The Vendor IDs are assigned by the USB Consortium, so for commercial use you either buy one, or find a partner with an appropriate licence who can allocate Product IDs for you. If you are developing an open-source device, you may use one of these services:

http://pid.codes/

http://wiki.openmoko.org/wiki/USB_Product_IDs

3. The CDC class is only complex in its descriptor, the actual data transfer is very straightforward: you can directly use USBD_LL_PrepareReceive() and USBD_LL_Transmit() functions to receive and transmit data through the VCP (packetizing is handled by the HAL, so you can call these with any length). Of course you should still rely on the CDC receive callback and TxState to determine if the previous transfer has completed.

Hello

cialdi

There is a composite example proposed under

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32-standard-peripheral-library-expansion/stsw-stm32html

.In the example, the independent interfaces are : Mass Storage (MSC) and Custom HID.

MSC_HID_Composite

Khouloud.