uarttest.c

串口检测程序

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/types.h>

typedef unsigned char u8;
typedef unsigned int u32;
int speed_arr[] =
  { B9600, B19200, B57600, B115200, B500000, B1000000, B2000000 };
int name_arr[] = { 9600, 19200, 57600, 115200, 500000, 1000000, 2000000 };
char *dev_name[] = { "/dev/ttyS0", "/dev/ttyS1", "/dev/ttyS2", "/dev/ttyS3" };

void
setspeed (int fd, int speed)
{
  int i;
  int status;
  printf ("set baudrate:%d\n", speed);
  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 fd");
	  return;}
	}
      tcflush (fd, TCIOFLUSH);
    }
}				//set speed of uart

int
main (int argc, char *argv[])
{
  int fd, rt;
  int w=0;
  int n_read, n_write;
  int i, n = 0;
  int speed = 0;		//baudrate
  u8 w_buf[100];
  char r_buf[100];
  
  char *dev={0};
  
  for(i=0;i<8;i++)
    {
    	w_buf[i]=i+1;
    }


  //read baudrate
  while ((rt = getopt (argc, argv, "hwb:c:")) >= 0)
    switch (rt)
      {
      case 'h':
	printf ("Usage:%s [-h] [-w] [-b] [baudrate] [-c] [/dev/ttyS*] \n"
		"\t-b set the uart baudrate!\n"
		"\t-w write the uart before read it!\n"
		"\t-c the uart NO.", argv[0]);
	return 0;
      case 'b':
	speed = atoi (optarg);
	printf ("get baudrate:%d\n", speed);
	break;
      case 'w':
	w=1;
        break;
      case 'c':
	dev = dev_name[atoi (optarg)];
	break;
      }

  //open uart
  if ((fd = open (dev, O_RDWR | O_NONBLOCK)) == -1)
    {
      perror ("open uart:");
      return 0;
    }


  if (!speed)
    {
      printf ("error:set baudrate first\n");
      return 0;
    }

  //set this uart baudrate
  setspeed (fd, speed);

  //init uart
  struct termios options;
  if ((tcgetattr (fd, &options)) != 0)
    {
      printf ("tcgetattr failed!");
      return 1;
    }
  printf ("get cflag:%08x\n", options.c_cflag);
//  options.c_cflag |= (CLOCAL | CREAD);
  options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
  options.c_iflag &= ~(IXON | IXOFF | IXANY);
  options.c_oflag &= ~OPOST;
//  options.c_oflag &= ~CRTSCTS;
//  options.c_cflag &= ~ CSTOPB;
//  options.c_cflag &= ~PARENB;
  tcsetattr (fd, TCSANOW, &options);

  //read and write uart
  while (1)
    {
      if (w)
	n_write = write (fd, w_buf, 8);
      if ((n_read = read (fd, r_buf, 8)) > 0)
         {	
	  for (i = 0; i < n_read; i++)
	    {
	      printf ("%02x ", r_buf[i]);
	      n++;
	      if (n == 8)
		{
		  printf ("\n");
		  n = 0;
		}
	    }
         }
       
	
    }
  close (fd);
}