[Ftdi-usb-sio-devel] Communication problems between Ubuntu Linux and Suunto D6 over FTDI usbserial

[Matti D. <ma...@77...>]

Hello - I'm writing a piece of software to talk to my dive computer Suunto 
D6 from a linux machine, since Suunto only provides Windows software for 
extracting the dive data. To do this I have written some serial code to 
talk to the dive computer over the FTDI driver. Plugging the device in the 
USB port, the FTDI driver immediately properly loads and creates 
/dev/ttyUSB0. I then succesfully open the port, write data to it, but 
never get anything back. There just is no reply from the device. I have 
verified the protocol format using a byte by byte Serial sniffer on a 
Windows machine, where the exact same sequence works properly.

Perhaps there is something wrong in the way I initialize the FTDI serial 
port?

Code below:

---------------------------------------------------------------------
    m_fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_SYNC);
    if ( m_fd == -1 )
    {
      perror("failed to open serial port - ");
      exit(-1);
    }

    // configure the new port settings for 9600baud, 8N1, raw output
    termios options = termios();
    options.c_cflag = B9600 | CS8 | CLOCAL | CREAD;
    options.c_iflag = 0;
    options.c_oflag = 0;
    options.c_lflag = 0;

    // 1 second port read timeout
    options.c_cc[VMIN]  = 0;
    options.c_cc[VTIME] = 10;

    // register the new port settings
    tcflush(m_fd, TCIFLUSH);
    if ( tcsetattr(m_fd, TCSANOW, &options) == -1 )
    {
      perror("tcsetattr() failed - ");
      exit(-1);
    }
---------------------------------------------------------------------

After that I just use write(2) and read(2) for rx/tx. I have tried pretty 
much every port setting I could think of, and even tried manually setting 
the DSR flag.

I am out of options debugging this, and would very much like to get it 
running in order not have to have a Windows installation for this single 
thing..


BR,

Matti