Question
Nucleo-F411RE and dev/ttyS3 communication
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;
}