Linux串口编程之发送

#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，例程基于<span style="font-family: MicrosoftYaHei; font-size: 12pt;">Exynos4412<br style="orphans: 2; text-align: -webkit-auto; widows: 2;" /></span>
//打开串口
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);//串口设置
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);
}

//串口设置函数
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;
}