Linux串口編程之發送

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>

int set_opt(int,int,int,char,int);
void main()
{
	int fd,wr_static,i=10;
	char *uart3 = "/dev/ttySAC3";
	char *buffer = "hello world!\n";
	
	printf("\r\n4412 uart3 writetest start\r\n");//打印信息，例程基於<span style="font-family: MicrosoftYaHei; font-size: 12pt;">Exynos4412<br style="orphans: 2; text-align: -webkit-auto; widows: 2;" /></span>
	//打開串口
	if((fd = open(uart3, O_RDWR|O_NOCTTY|O_NDELAY))<0){
		printf("open %s is failed",uart3);
	}
	else{
		printf("open %s is success\n",uart3);
		set_opt(fd, 115200, 8, 'N', 1);//串口設置 
		while(i--)
		{
			wr_static = write(fd,buffer, strlen(buffer));
			if(wr_static<0)
				printf("write failed\n");
			else{
				printf("wr_static is %d\n",wr_static);
			}
			sleep(1);
		}
	}
	close(fd);
}

//串口設置函數
int set_opt(int fd,int nSpeed, int nBits, char nEvent, int nStop)
{
	struct termios newtio,oldtio;
	if  ( tcgetattr( fd,&oldtio)  !=  0) { 
		perror("SetupSerial 1");
		return -1;
	}
	bzero( &newtio, sizeof( newtio ) );
	newtio.c_cflag  |=  CLOCAL | CREAD;
	newtio.c_cflag &= ~CSIZE;

	switch( nBits )
	{
	case 7:
		newtio.c_cflag |= CS7;
		break;
	case 8:
		newtio.c_cflag |= CS8;
		break;
	}

	switch( nEvent )
	{
	case 'O':
		newtio.c_cflag |= PARENB;
		newtio.c_cflag |= PARODD;
		newtio.c_iflag |= (INPCK | ISTRIP);
		break;
	case 'E': 
		newtio.c_iflag |= (INPCK | ISTRIP);
		newtio.c_cflag |= PARENB;
		newtio.c_cflag &= ~PARODD;
		break;
	case 'N':  
		newtio.c_cflag &= ~PARENB;
		break;
	}

	switch( nSpeed )
	{
	case 2400:
		cfsetispeed(&newtio, B2400);
		cfsetospeed(&newtio, B2400);
		break;
	case 4800:
		cfsetispeed(&newtio, B4800);
		cfsetospeed(&newtio, B4800);
		break;
	case 9600:
		cfsetispeed(&newtio, B9600);
		cfsetospeed(&newtio, B9600);
		break;
	case 115200:
		cfsetispeed(&newtio, B115200);
		cfsetospeed(&newtio, B115200);
		break;
	case 460800:
		cfsetispeed(&newtio, B460800);
		cfsetospeed(&newtio, B460800);
		break;
	default:
		cfsetispeed(&newtio, B9600);
		cfsetospeed(&newtio, B9600);
		break;
	}
	if( nStop == 1 )
		newtio.c_cflag &=  ~CSTOPB;
	else if ( nStop == 2 )
	newtio.c_cflag |=  CSTOPB;
	newtio.c_cc[VTIME]  = 0;
	newtio.c_cc[VMIN] = 0;
	tcflush(fd,TCIFLUSH);
	if((tcsetattr(fd,TCSANOW,&newtio))!=0)
	{
		perror("com set error");
		return -1;
	}
//	printf("set done!\n\r");
	return 0;
}