Administrace komentářů

Ahoj, zkusil jsem tento kod jenom s drobnou upravou:

root@desktop:~/abc$ cat Makefile
CFLAGS=-g -Wall
ser: captain/capser.c ser.c
    gcc -g -c -Wall captain/capser.c -o capser.o
    gcc -g -c -Wall ser.c -o ser.o
    gcc ser.o capser.o -o ser

##############################################################################
root@desktop:~/abc$ cat ser.c
/* ser.c
    (C) 2004-5 Captain http://www.captain.at
   
    Sends 3 characters (ABC) via the serial port (/dev/ttyS0) and reads
    them back if they are returned from the PIC.
   
    Used for testing the PIC-MMC test-board
    http://www.captain.at/electronic-index.php

*/
#include <stdio.h>   /* Standard input/output definitions */
#include <string.h>  /* String function definitions */
#include <unistd.h>  /* UNIX standard function definitions */
#include <fcntl.h>   /* File control definitions */
#include <errno.h>   /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */

#include "captain/capser.h"

int fd;

int initport(int fd) {
    struct termios options;
    // Get the current options for the port...
    tcgetattr(fd, &options);
    // Set the baud rates to 19200...
    cfsetispeed(&options, B9600);
    cfsetospeed(&options, B9600);
    // Enable the receiver and set local mode...
    options.c_cflag |= (CLOCAL | CREAD);

    options.c_cflag &= ~PARENB;
    options.c_cflag &= ~CSTOPB;
    options.c_cflag &= ~CSIZE;
    options.c_cflag |= CS8;

    // Set the new options for the port...
    tcsetattr(fd, TCSANOW, &options);
    return 1;
}

int main(int argc, char **argv) {

    fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1) {
        perror("open_port: Unable to open /dev/ttyS0 - ");
        return 1;
    } else {
        fcntl(fd, F_SETFL, 0);
    }
   
    printf("baud=%d\n", getbaud(fd));
    initport(fd);
    printf("baud=%d\n", getbaud(fd));

    char sCmd[254] = "VERZE";

    if (!writeport(fd, sCmd)) {
        printf("write failed\n");
        close(fd);
        return 1;
    }

    printf("written:%s\n", sCmd);
   
    usleep(500000);
    char sResult[254];
    fcntl(fd, F_SETFL, FNDELAY); // don't block serial read

    if (!readport(fd,sResult)) {
        printf("read failed\n");
        close(fd);
        return 1;
    }
    printf("readport=%s\n", sResult);
    close(fd);
    return 0;
}

##############################################################################
root@desktop:~/abc$ cat captain/capser.h
int writeport(int fd, char *chars);
int readport(int fd, char *result);
int getbaud(int fd);

##############################################################################
root@desktop:~/abc$ cat captain/capser.c
/* capser.c
    (C) 2004-5 Captain http://www.captain.at
   
    Helper functions for "ser"
   
    Used for testing the PIC-MMC test-board
    http://www.captain.at/electronic-index.php
*/
#include <stdio.h>   /* Standard input/output definitions */
#include <string.h>  /* String function definitions */
#include <unistd.h>  /* UNIX standard function definitions */
#include <fcntl.h>   /* File control definitions */
#include <errno.h>   /* Error number definitions */
#include <termios.h> /* POSIX terminal control definitions */

int writeport(int fd, char *chars) {
    int len = strlen(chars);
    chars[len] = 0x0d; // stick a <CR> after the command
    chars[len+1] = 0x00; // terminate the string properly
    int n = write(fd, chars, strlen(chars));
    if (n < 0) {
        fputs("write failed!\n", stderr);
        return 0;
    }
    return 1;
}

int readport(int fd, char *result) {
    int iIn = read(fd, result, 254);
    result[iIn-1] = 0x00;
    if (iIn < 0) {
        if (errno == EAGAIN) {
            printf("SERIAL EAGAIN ERROR\n");
            return 0;
        } else {
            printf("SERIAL read error %d %s\n", errno, strerror(errno));
            return 0;
        }
    }                   
    return 1;
}

int getbaud(int fd) {
    struct termios termAttr;
    int inputSpeed = -1;
    speed_t baudRate;
    tcgetattr(fd, &termAttr);
    /* Get the input speed.                              */
    baudRate = cfgetispeed(&termAttr);
    switch (baudRate) {
        case B0:      inputSpeed = 0; break;
        case B50:     inputSpeed = 50; break;
        case B110:    inputSpeed = 110; break;
        case B134:    inputSpeed = 134; break;
        case B150:    inputSpeed = 150; break;
        case B200:    inputSpeed = 200; break;
        case B300:    inputSpeed = 300; break;
        case B600:    inputSpeed = 600; break;
        case B1200:   inputSpeed = 1200; break;
        case B1800:   inputSpeed = 1800; break;
        case B2400:   inputSpeed = 2400; break;
        case B4800:   inputSpeed = 4800; break;
        case B9600:   inputSpeed = 9600; break;
        case B19200:  inputSpeed = 19200; break;
        case B38400:  inputSpeed = 38400; break;
    }
    return inputSpeed;
}

root@desktop:~/abc$

Po zapnuti PC program vubec nefunguje:

root@desktop:~/abc$ make && ./ser
gcc -g -c -Wall captain/capser.c -o capser.o
gcc -g -c -Wall ser.c -o ser.o
gcc ser.o capser.o -o ser
baud=9600
baud=9600
written:VERZE
readport=VERZE
root@desktop:~/abc$ 

Musim spustit minicom, odeslat do portu libovolny text a pak dat z menu ukoncit bez resetu. Pak uz program funguje:

root@desktop:~/abc$ make && ./ser
gcc -g -c -Wall captain/capser.c -o capser.o
gcc -g -c -Wall ser.c -o ser.o
gcc ser.o capser.o -o ser
baud=9600
baud=9600
written:VERZE
readport=VERZE
0.1
OK
root@desktop:~/abc$ 

cim to muze byt? Dale by mne zajimalo, proc prijaty text obsahuje:

VERZE
0.1
OK

kdyz mel byt pouze

0.1
OK

cim to muze byt?