使用USB串行转换器通过Mac OS X与电源通信

Question

I am trying to talk to a power supply from my mac OS X Yosemite. The code works fine on a linux machine, but when I try it on my mac, it does not work. I am using a usb-serial converter and have downloaded the PL-2303 driver. The driver shows up in my /dev folder as cu.usbserial and tty.usbserial.

The part of my code that fails:

fd = initserial("/dev/cu.usbserial");

int initserial(char port[])
{
  struct termios shimtermios;
  int fd;

  if((fd=open(port,O_RDWR)) < 0)  {
    perror("Opening the RS-232 port failed for initserial\n");
    exit(-1);
  }

  if (tcgetattr(fd, &shimtermios) < 0) { 
    perror("couldn't get terminal attributes\n");
    exit(-2);
  }

  shimtermios.c_iflag=012005;
  shimtermios.c_oflag=014004;
  shimtermios.c_cflag=03206276;
  shimtermios.c_lflag=05060;
  cfsetospeed(&shimtermios,B19200);

  if (tcsetattr(fd, TCSAFLUSH, &shimtermios) < 0) {
    perror("couldn't set terminal attributes\n");
    exit(-3);
  }
  return (fd);
}

I get the following error message

couldn't set terminal attributes
: Invalid argument

Please let me know if you have any experience with this linux/unix issue. Thank you so much!

Answer 1

See the termios man page for the valid masks that can be used for c_iflag , c_oflag , c_cflag , and c_lflag ). You should OR the mask constants together rather than hard-coding the values.

Also from experience, FTDI USB-serial converters tend to work better on OS X than pl2303. OS X has a built-in driver for these (AppleUSBFTDI).