Introduction - If you have any usage issues, please Google them yourself
The serial port is a part of system resources, and its essence is used as the CPU and the serial code converter between devices. When the data from the CPU through the serial port to send out, the byte data is converted into a serial bit (Bit) receiving data, the serial data bits are converted into bytes. Applications using serial communication, you must use the resources made prior to application to the operating system requirements (ie open the serial port), after the completion of the release of communication resources (ie close the serial port). Serial communication can generally be divided into synchronous and asynchronous mode of operation. The so-called synchronous mode means that the serial receive buffer to read the required number of data until all the required number of data to be read out or set timeout period has expired before returning. If the specified amount of data to be read and set the timeout time is longer, and the receive buffer is small, it may cause the thread