I use STM32F105XX STM32F401XX have realized the USB HID interface; Only STM32F103C8T6 this not line, I got a lot of examples, set up directly with STM32CubeMX USB HID out of the project, connecting computers are prompt device descriptor attempt failed, I also tried many group device descriptor results are the same, on the DP has 1.5 K to 3.3 V, external crystals is 8 m, now please have greatly provide one set of the project, OK requirements must be MDK - ARM USES HAL library, due to the limitation hardware design way DOWN program to use ST - Link, thank you very much,