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Nucleo-F411RE and dev/ttyS3 communication

Max75
Associate II

Hello !

My Nucleo-F411RE board is visible in Cygwin as dev/ttyS3. I try to send message "Hello !" to Nucleo and receive answer from it, but inside the code I found in the internet, the functions tcgetattr() and tggetattr() return the error Invalid argument. How to fix this ?

 

I give the code below... 

#include <errno.h>
#include <fcntl.h> 
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <stdio.h>

int set_interface_attribs (int fd, int speed, int parity)
{
    struct termios tty;
    if (tcgetattr (fd, &tty) != 0)
    {
        perror("error from tcgetattr\r\n");
        return -1;
    }

    cfsetospeed (&tty, speed);
    cfsetispeed (&tty, speed);

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit chars
    // disable IGNBRK for mismatched speed tests; otherwise receive break
    // as \000 chars
    tty.c_iflag &= ~IGNBRK;         // disable break processing
    tty.c_lflag = 0;                // no signaling chars, no echo,
                                        // no canonical processing
    tty.c_oflag = 0;                // no remapping, no delays
    tty.c_cc[VMIN]  = 0;            // read doesn't block
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
                                    // enable reading
    tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
    {
        perror("error from tcsetattr\r\n");
        return -1;
    }
    return 0;
}

void set_blocking (int fd, int should_block)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);
    if (tcgetattr (fd, &tty) != 0)
    {
        perror("error from tggetattr\r\n");
        return;
    }

    tty.c_cc[VMIN]  = should_block ? 1 : 0;
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
        perror("error setting term attributes\r\n");
}

int main(void)
{
char *portname = "dev/ttyS3";
 
    int fd = open (portname, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd < 0)
    {
        perror("error opening port\r\n");
        return 0;
    }

    set_interface_attribs (fd, B9600, 0);  // set speed to 9,600 bps, 8n1 (no parity)
    set_blocking (fd, 0);                // set no blocking

    write (fd, "hello!\n", 7);           // send 7 character greeting

    usleep ((7 + 25) * 100);             // sleep enough to transmit the 7 plus
                                     // receive 25:  approx 100 uS per char transmit
    char buf [100];
    read (fd, buf, sizeof buf);  // read up to 100 characters if ready to read
    printf("%s\r\n", buf);
    
    return 0;
    
}

 

2 REPLIES 2

That's linux code to run on your Host system - right?

That's beyond the scope of this forum! Try a linux programming forum.

Test it against a terminal...

 


@Max75 wrote:

the functions tcgetattr() and tggetattr() return the error Invalid argument. How to fix this ?


Supply arguments which are valid!

https://linux.die.net/man/3/tcgetattr

 

PS:

There is no such function as tggetattr() - it appears to be just a typo in this message:

void set_blocking (int fd, int should_block)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);
    if (tcgetattr (fd, &tty) != 0)
    {
        perror("error from tggetattr\r\n");  // <<< here!
        return;
    }

 

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.
Max75
Associate II

Hello, Andrew !

Are you angry ? :)

About of topic theme. I comment these function callings  and it works. My Cygwin received message well, but Nucleo board received garbage. Working at this...