baudrate.c

#include <stdio.h>
#include <sys/types.h>
#include <termios.h>
#include <fcntl.h>
#include <stdlib.h>

#define SERIAL_DEVICE	"/dev/ttyUSB0"

int main()
{
	struct termios serial_port_settings;
	int fd;
	int retval;

	fd = open(SERIAL_DEVICE, O_RDWR);
	if (fd < 0) {
		perror("Failed to open SERIAL_DEVICE");
		exit(1);
	}
	
	retval = tcgetattr(fd, &serial_port_settings);
	if (retval < 0) {
		perror("Failed to get termios structure");
		exit(2);
	}

	//setting baud rate to B38400
	retval = cfsetospeed(&serial_port_settings, B38400);
	if (retval < 0) {
		perror("Failed to set 38400 output baud rate");
		exit(3);
	}
	retval = cfsetispeed(&serial_port_settings, B38400);
	if (retval < 0) {
		perror("Failed to set 38400 input baud rate");
		exit(4);
	}
	retval = tcsetattr(fd, TCSANOW, &serial_port_settings);
	if (retval < 0) {
		perror("Failed to set serial attributes");
		exit(5);
	}
	printf("Successfully set the baud rate\n");
	close(fd);
	return 0;
}