设置STM32的DMA，利用它来实现串口数据传送，并在TFT-LCD模块上显示当前的传送进度，打开串口调试工具，按住轻触开关则可看到界面的信息-Set the STM32 DMA, use it to serial data transmission, and in the TFT-LCD module displays the current transfer progress, open the serial port debugging tool, hold down the touch