Re: 8ms Timer for serial port access

From: Jens Schumacher (jens.schumache_at_gmx.net)
Date: 10/31/03 

Date: Thu, 30 Oct 2003 22:38:38 -0500

Am 30/10/03 19:38 Uhr schrieb "Floyd Davidson" unter <floyd@barrow.com> in
87brry1bss.fld@barrow.com:

> There are some very good examples of how that should be done
> available on the Internet, but there are even more really bad
> examples. The Linux Serial-Programming-HOWTO is one of the less
> than quality examples...

OK here comes my code...thought it is a good one because it is recommended a
lot.

int serial_open(char *portName)
{
  int fd = 0; // file descriptor

  /* Close file if already open */
  if (fd > 0) {
    close(fd);
  }
  
  /* open the specified serial port in for read and write O_RDWR */
  /* NO_CTTY makes it a non-controlling TTY. */
  fd = open(portName, O_RDWR | O_NOCTTY );
  
  if (fd < 0) {
    perror(portName);
    return -1;
  }

  /* Get current port configuration */
  tcgetattr(fd, &(oldtio));
  
  cfsetispeed(&newtio, B38400);
  cfsetospeed(&newtio, B38400);
   

  /* We've got baudrate. Add other options. */
  newtio.c_cflag |= CS8 | CLOCAL | CREAD;
  newtio.c_iflag = IGNPAR;
  newtio.c_oflag = 0;
 
  newtio.c_cc[VTIME] = 0;
  newtio.c_cc[VMIN] = 10;

  /* try and configure the port appropriately... */
  tcflush(fd, TCIFLUSH);
  tcsetattr(fd, TCSANOW, &newtio);

  serial_flush (fd);
  
  return fd;
}

Thanks, Jens

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