串口收发程序
//ubutnu下串口通信，数据收发
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#define BAUDRATE B115200 ///Baud rate : 115200
#define DEVICE "/dev/ttyUSB0"//设置你的端口号
int nFd = 0;
struct termios stNew;
struct termios stOld;
//Open Port & Set Port
int SerialInit()
{
nFd = open(DEVICE, O_RDWR|O_NOCTTY|O_NDELAY);
if(-1 == nFd) {
perror("Open Serial Port Error!\n");
return -1;
}
if( (fcntl(nFd, F_SETFL, 0)) < 0 )
{
perror("Fcntl F_SETFL Error!\n");
return -1;
}
if(tcgetattr(nFd, &stOld) != 0)
{
perror("tcgetattr error!\n");
return -1;
}
stNew = stOld;
cfmakeraw(&stNew);//将终端设置为原始模式，该模式下全部的输入数据以字节为单位被处理
//set speed
cfsetispeed(&stNew, BAUDRATE);//115200
cfsetospeed(&stNew, BAUDRATE);
//set databits
stNew.c_cflag |= (CLOCAL|CREAD);
stNew.c_cflag &= ~CSIZE;
stNew.c_cflag |= CS8;
//set parity
stNew.c_cflag &= ~PARENB;
stNew.c_iflag &= ~INPCK;
//set stopbits
stNew.c_cflag &= ~CSTOPB;
stNew.c_cc[VTIME]=0; //指定所要读取字符的最小数量
stNew.c_cc[VMIN]=1; //指定读取第一个字符的等待时间，时间的单位为n*100ms
//假设设置VTIME=0，则无字符输入时read（）操作无限期的堵塞
tcflush(nFd,TCIFLUSH); //清空终端未完毕的输入/输出请求及数据。
if( tcsetattr(nFd,TCSANOW,&stNew) != 0 )
{
perror("tcsetattr Error!\n");
return -1;
}
return nFd;
}
int main(int argc, char **argv)
{
int i;
int nRet = 0;
char *sendmsg="ATI";
int SIZE=sizeof(sendmsg); //sizeof对指针无用，后面修改
char buf[SIZE];
if( SerialInit() == -1 )
{
perror("SerialInit Error!\n");
return -1;
}
bzero(buf, SIZE);
while(1)
{
sleep(1);
write(nFd,sendmsg,sizeof(sendmsg));//向串口发送数据
printf("%s\n",sendmsg);
//串口接收部分
nRet = read(nFd, buf, SIZE);
if(-1 == nRet)
{
perror("Read Data Error!\n");
break;
}
if(0 < nRet)
{
buf[nRet] = 0;
printf("Recv Data: %s\n", buf);
}
}
close(nFd);
return 0;
}
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