uart测试代码

#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*/
#include     <sys/time.h>


/***@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 TRUE 1
#define FALSE -1

int speed_arr[] = {B115200, B38400, B19200, B9600, B4800, B2400, B1200, B300,
        B38400, B19200, B9600, B4800, B2400, B1200, B300, };

int name_arr[] = {115200, 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);

    /*  设置串口的波特率 */
        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 */
        options.c_iflag &= ~(ICRNL|IGNCR);
        options.c_lflag &= ~(ICANON );
        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_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[16];
  //char *dev ="/dev/ttySAC1"; 
   int i=0;
   const char* dev   = NULL;
   const char* string   = NULL;
   const char* type = NULL;


    dev   = argv[1];
    string = argv[2];
    type = argv[3];

    if(dev==NULL)
    {
      printf("Please input seria device name ,for exmaple /dev/ttyO1.\nNote:This is loop test application. Make sure that your serial is loop\n");
      return 0;
    }

    /*  打开串口 */

    fd = OpenDev(dev);
    if (fd>0)
        set_speed(fd,19200); //设置波特率
    else
    {
    printf("Can't Open Serial Port!\n");
    exit(0);
    }

      if (set_Parity(fd,8,1,'N')== FALSE)  //设置传递参数
      {
        printf("Set Parity Error\n");
        exit(1);
      }    

    printf("\nWelcome to TTYtest type:%s\n",type);    


      while(1)
      {        

        if(strcmp(type,"1") == 0){
        if ((nread = read(fd, buff, 15))>0)
               {
               printf("\nLen %d\n", nread);
                buff[nread+1] = '\0';
               printf("read %s\n", buff);
    
               }
        }
        else{
            write(fd, string, strlen(string));
            printf("Send test data------%s\n",string);  

        }

        sleep(1);
         }
}