Programming

no, your code is very complicated!

It's a library, you can just use it without modifying. It's the same one I use for nearly all my serial code(i.e. I use it quite a lot -- both serial ports and three USB serial converters on our server are occupied already).

Why not try it. It even included example code. I'll make it plainer:

You do this:

Code:

$ cat <<EOF >mycode.c
#include <stdio.h>
#include <unistd.h>
#include "tcgets.h"

int main(void)
{
        int fd=termios_open("/dev/ttyUSB3", "115200N81");
        ssize_t bw;

        if(fd<0)
        {
                perror("Couldn't open ttyUSB3");
                return(1);
        }

        bw=write(fd, "TEST", 4);
        fprintf(stderr, "Wrote %d bytes\n", bw);
        if(bw <= 0)
        {
                perror("Couldn't write");
                return(1);
        }
        return(0);
}

EOF

$ gcc mycode.c tcgets.c -o mycode
$ ./mycode

ah ok tomorrow i try.. now good night and thanks

i was having the same trouble as you: was able to send, but not read from the serial terminal. After some hackery, i figured out i was missing a settings:

i had to enable hardware flow control, and match the correct speed.

tcgetattr(fdInputStream, &options);

//set port speed
cfsetispeed(&options, B230400);
cfsetospeed(&options, B230400);

//enable reader, indicate that hw-flow-control is active
options.c_cflag |= (CLOCAL | CREAD | CRTSCTS);

//set 8n1
options.c_cflag &= ~PARENB; /* Enable parity bit */
options.c_cflag &= ~CSTOPB; /* 2 stop bits (1 otherwise) */
options.c_cflag &= ~CSIZE; /* Mask the character size bits */
options.c_cflag |= CS8; /* Select 8 data bits */
//set raw input
options.c_lflag &= ~(ICANON | /* Enable canonical input (else raw) */
ECHO | /*Enable echoing of input characters */
ECHOE | /*Echo erase character as BS-SP-BS*/
ISIG); /*Enable SIGINTR, SIGSUSP, SIGDSUSP, and SIGQUIT signals*/

Also, if you have another program that can read from the same serial port (e.g. demo program) you can always check the current settings for the serial device

e.g.
stty -f /dev/tty.mydevice