It requires the use of system calls such as open(), read(), write(), ioctl(), and close(). Serial port programming in C Linux involves the use of the Linux APIs to communicate with devices that use a serial port connection. We can connect to the serial port once the device has been identified. The USB converter must be plugged in in Linux, and we must use the dmesg command to identify the device’s file name. We will need to configure the Serial line so that it corresponds to the COM port noted earlier, as well as the serial console speed to 9600. To connect to a serial COM port via a terminal emulator, such as PuTTY, we can use the connection type Serial. To accomplish this, we must first create a new termios struct before writing the serial port’s configuration using tcgetattr(), then modify the parameters to meet our requirements and save the settings using tcsetattr() later. Accessing Serial Ports In Cīefore we can access the serial port in C, we must first read the termios struct. Lastly, the serial port can also be configured with other parameters such as flow control, break signals, and other control lines.

The close() function is then used to close the port when it is no longer needed. Once the port is open, the functions read() and write() can be used to read and write data from and to the serial port. Next, the serial port can be opened with the open() function in the C library. Accessing serial port in C can be done by first setting up the port parameters such as the baud rate, number of data bits, parity, and stop bits.

Uart serial communication pdf