Linux(妙算)串口通信

来源：互联网发布：麒麟linux 编辑：程序博客网时间：2024/05/16 12:42
妙算上搭载的Linux，其串口操作与普通Linux相同。
通过官方文档可知，妙算共有四个串口可用，
本次实验使用串口1，其对应的设备为/dev/ttyTHS0,为盒子上的13和15号引脚。
其接线如图所示
代码

#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*//*@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 */#define FALSE 1#define TRUE 0char *recchr="We received:\"";int speed_arr[] = { B921600, B460800, B230400, B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300, B38400, B19200, B9600, B4800, B2400, B1200, B300, };int name_arr[] = {921600, 460800, 230400, 115200, 57600, 38400,  19200,  9600,  4800,  2400,  1200,  300, 38400,  19200,  9600, 4800, 2400, 1200,  300, };void set_speed(int fd, int speed){  int   i;  int   status;  struct termios   Opt;  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 fd1");      return;      }   tcflush(fd,TCIOFLUSH);   }}/* *@brief  设置串口数据位，停止位和效验位 *@param  fd       类型  int  打开的串口文件句柄* *@param  databits 类型  int  数据位   取值 为 7 或者8* *@param  stopbits 类型  int  停止位   取值为 1 或者2* *@param  parity   类型  int  效验类型 取值为N,E,O,,S */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;    options.c_cc[VTIME] = 150; // 15 seconds    options.c_cc[VMIN] = 0;  tcflush(fd,TCIFLUSH); /* Update the options and do it NOW */  if (tcsetattr(fd,TCSANOW,&options) != 0)   {    perror("SetupSerial 3");  return (FALSE); }  return (TRUE); }/* *@breif 打开串口 */int OpenDev(char *Dev){int fd = open( Dev, O_RDWR | O_NONBLOCK);         //| O_NOCTTY | O_NDELAY if (-1 == fd)  { /*设置数据位数*/   perror("Can't Open Serial Port");   return -1;  } else return fd;}/* *@breif  main() */int main(int argc, char *argv[]){    int fd;    int nread;    char buff[512];    char *dev ="/dev/ttyTHS0"; //Uart1    char recchr[512];    int temp=0;    sleep(1);    fd = OpenDev(dev); //1open uart    if (fd>0)    {        set_speed(fd,9600); //2set speed    }    else{        printf("Can't Open Serial Port!\n");        exit(0);    }    if (set_Parity(fd,8,1,'N')== FALSE) //3set parity    {        printf("Set Parity Error\n");        exit(1);    }while(1){    //read    if(nread=read(fd,buff,512)>0)    {        //printf("\nLen %d\n",nread);        buff[nread]='\0';        printf("received data:%s\n",buff);    }    temp++;    sprintf(recchr,"%04d",temp);    //write    write(fd, recchr, strlen(recchr));    printf("data:%d,send ok！\n",temp);    sleep(1);}    close(fd);    exit(0);}
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