Linux串口操作的一段代码
Linux串口操作的一段代码
Linux串口操作的一段代码:
- /*
- * termio.c
- *
- * Created on: 2011-11-2
- * Author: jieen
- */
- #include <stdio.h> /*标准输入输出定义*/
- #include <stdlib.h> /*标准函数库定义*/
- #include <unistd.h> /*Unix 标准函数定义*/
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h> /*文件控制定义*/
- #include <termios.h> /*PPSIX 终端控制定义*/
- #include <errno.h> /*错误号定义*/
- #if 0
- int main(void)
- {
- int fd;
- /*以读写方式打开串口*/
- fd = open( "/dev/ttyS0", O_RDWR);
- if (-1 == fd)
- {
- /* 不能打开串口一*/
- perror(" 提示错误!");
- }
- struct termios Opt;
- tcgetattr(fd, &Opt);
- printf("speed:%x\n",Opt.c_ispeed);
- cfsetispeed(&Opt,B115200); /*设置为115200Bps*/
- cfsetospeed(&Opt,B115200);
- tcsetattr(fd,TCANOW,&Opt);
- }
- #endif
- /**********************************************************************
- 代码说明:使用串口二测试的,发送的数据是字符,
- 但是没有发送字符串结束符号,所以接收到后,后面加上了结束符号。
- 我测试使用的是单片机发送数据到第二个串口,测试通过。
- **********************************************************************/
- #define FALSE -1
- #define TRUE 0
- /*********************************************************************/
- int OpenDev(char *Dev)
- {
- int fd = open( Dev, O_RDWR ); //| O_NOCTTY | O_NDELAY
- if (-1 == fd)
- {
- perror("Can't Open Serial Port");
- return -1;
- }
- else
- return fd;
- }
- int main(int argc, char **argv)
- {
- int fd;
- int nread;
- char *dev;
- char buff[512];
- dev = (char *)malloc(15);
- if(argc < 2)
- {
- strcpy(dev,"/dev/ttyS0"); //串口一
- }else
- {
- strncpy(dev,argv[1],strlen(argv[1]));
- }
- fd = OpenDev(dev);
- if(fd == -1)
- exit(EXIT_FAILURE);
- set_speed(fd,115200);
- if (set_Parity(fd,8,1,'N') == FALSE) {
- printf("Set Parity Error\n");
- exit (0);
- }
- while (1) //循环读取数据
- {
- while((nread = read(fd, buff, 512))>0)
- {
- printf("\nLen %d\n",nread);
- buff[nread+1] = '\0';
- printf( "\n%s", buff);
- }
- }
- //close(fd);
- // exit (0);
- }
- /**
- *@brief 设置串口通信速率
- *@param fd 类型 int 打开串口的文件句柄
- *@param speed 类型 int 串口速度
- *@return void
- */
- void set_speed(int fd, int speed){
- int i;
- int status;
- struct termios Opt;
- int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,
- B38400, B19200, B9600, B4800, B2400, B1200, B300, };
- int name_arr[] = {38400, 19200, 9600, 4800, 2400, 1200, 300, 38400,
- 19200, 9600, 4800, 2400, 1200, 300, };
- tcgetattr(fd, &Opt);
- for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++) {
- if (speed == name_arr[i]) {
- tcflush(fd, TCIOFLUSH);
- cfsetispeed(&Opt, speed_arr[i]);
- cfsetospeed(&Opt, speed_arr[i]);
- status = tcsetattr(fd, TCSANOW, &Opt);
- if (status != 0) {
- perror("tcsetattr fd");
- return;
- }
- tcflush(fd,TCIOFLUSH);
- }
- }
- }
- int set_Parity(int fd,int databits,int stopbits,int parity)
- {
- struct termios options;
- if ( tcgetattr( fd,&options) != 0) {
- perror("SetupSerial 1");
- return(FALSE);
- }
- options.c_cflag &= ~CSIZE;
- switch (databits) /*设置数据位数*/
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default:
- fprintf(stderr,"Unsupported data size\n"); return (FALSE);
- }
- switch (parity)
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB; /* Clear parity enable */
- options.c_iflag &= ~INPCK; /* Enable parity checking */
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB); /* 设置为奇效验*/
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB; /* Enable parity */
- options.c_cflag &= ~PARODD; /* 转换为偶效验*/
- options.c_iflag |= INPCK; /* Disnable parity checking */
- break;
- case 'S':
- case 's': /*as no parity*/
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;break;
- default:
- fprintf(stderr,"Unsupported parity\n");
- return (FALSE);
- }
- /* 设置停止位*/
- switch (stopbits)
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default:
- fprintf(stderr,"Unsupported stop bits\n");
- return (FALSE);
- }
- /* Set input parity option */
- if (parity != 'n')
- options.c_iflag |= INPCK;
- tcflush(fd,TCIFLUSH);
- options.c_cc[VTIME] = 150; /* 设置超时15 seconds*/
- options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
- if (tcsetattr(fd,TCSANOW,&options) != 0)
- {
- perror("SetupSerial 3");
- return (FALSE);
- }
- return (TRUE);
- }
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