用DMA实现串口数据的收发，采用中断模式，实现数据在串口间的传送-The DMA is used to implement a serial port to send and receive data, using interrupt mode, implement the data transfer between a serial port

基于stm32开发板的DMA串口通讯程序，可实现数据的准确收发，发送一串数据返回相同的数据-dma serial communication program, enabling accurate data transceiver