Posted on May 27, 2017 at 20:00Something like this, incomplete example, error checking and other stuff skipped:
(Seems the 'Formatting as Souce Code' option is pretty useless)
♯ include <unistd.h>
♯ include <stdio.h> // Standard input/output definitions
♯ include <stdlib.h> // standard library functions
♯ include <fcntl.h> // File control definitions
♯ include <termios.h> // POSIX terminal control definitions
♯ include <string.h> // String function definitions
♯ include <errno.h> // Error number definitions
your_function_here ()
{
...
struct termios options, oldoptions;
...
iFD = openLine (iSerLine, devtype);
...
// Configure port reading; block read(), until data arrive
fcntl (iFD, F_SETFL, 0);
// Get the current options for the port, and copy for restoration
tcgetattr (iFD, &oldoptions);
memcpy (&options, &oldoptions, sizeof (struct termios));
// Set the baud rates to the defined value
cfsetispeed (&options, iBaudRate);
cfsetospeed (&options, iBaudRate);
// Enable the receiver and set local mode
options.c_cflag |= (CLOCAL | CREAD);
options.c_cflag &= ~PARENB; // Mask the character size to 8 bits, no parity
options.c_cflag &= ~CSTOPB;
options.c_cflag &= ~CSIZE;
options.c_cflag |= CS8; // Select 8 data bits
if (hwFCntl)
options.c_cflag |= CRTSCTS; // enable hardware flow control
else
options.c_cflag &= ~CRTSCTS; // Disable hardware flow control
// Enable data to be processed as raw input
options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
options.c_iflag &= ~(ICRNL | INLCR | IXON | IXOFF);
options.c_oflag &= ~OPOST;
options.c_cc[VTIME] = 0; // no inter-character timer
options.c_cc[VMIN] = 1; // number of characters expected
// options.c_cc[VEOF] = 4;
// enable the new options for the port
tcsetattr (iFD, TCSANOW, &options);
}
static int openLine (int iSerLine, int devtype)
{
if (devtype == DEVTYPE_SERIAL)
sprintf (devName, '/dev/ttyS%d', iSerLine);
else
sprintf (devName, '/dev/ttyUSB%d', iSerLine);
// (fd == -1) -> Could not open the port
return (iFD = open (devName, O_RDONLY | O_NOCTTY | O_NDELAY));
}
Works for me, at least (Linux Mint 17 Distro).
