UART的全称是通用异步收发器（Universal Asynchronous Receiver/Transmitter），是实现设备之间低速数据通信的标准协议。“异步”指不需要额外的时钟线进行数据的同步传输，是一种串行总线接口，只需占用两根线就可以完成数据的收发（一根接收数据，一根发送数据），常用的标准通信波特率有9600bps、115200bps等。-UART stands for Universal Asynchronous Receiver Transmitter (Universal Asynchronous Receiver/Transmitter), a standard protocol for the low-speed data communication between devices. "Asynchronous" refers to the synchronous transmission of data does not require an additional clock line is a serial bus interface occupies only two lines can be completed transmission and reception of data (a received data, a transmission data), commonly used standard communication baud rate 9600bps, 115200bps.