说明：  1,将STM32的USB枚举为HID设备。 2,STM32使用3个端点，端点0用于枚举用，端点1和2用于数据的发送和接收。 3,端点长度为64，也就是单次最多可以传输64个字节数据。 4,STM32获取上位机下发的数据并将该数据通过USB原样返回，同时将数据打印输出。 5,上位机程序通过调用windows的API实现对HID设备的读写控制。
(1, the STM32 USB enumeration HID devices. 2, STM32 three endpoints, endpoint 0 for enumerating endpoint 1 and 2 are used to send and receive data. 3, the endpoint of length 64, that is a single can transmit up to 64 bytes of data. 4, STM32 access to the data issued by the host computer via USB and the data is returned unchanged, while the data printout. 5, the PC program by calling the windows API to read and write control of HID devices.)