Salut a tous
J'ai un petit souci :~ avec un programme c trouvé à cette adresse: todbot blog – Random experiments, circuits, code, rapid prototyping, sometimes things to buy, and the odd tune by Tod Kurt. qui permet de recevoir des données. voici le code c:
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <getopt.h>
void usage(void);
int serialport_init(const char* serialport, int baud);
int serialport_writebyte(int fd, uint8_t b);
int serialport_write(int fd, const char* str);
int serialport_read_until(int fd, char* buf, char until);
void usage(void) {
printf("Usage: arduino-serial -p <serialport> [OPTIONS]\n"
"\n"
"Options:\n"
" -h, --help Print this help message\n"
" -p, --port=serialport Serial port Arduino is on\n"
" -b, --baud=baudrate Baudrate (bps) of Arduino\n"
" -s, --send=data Send data to Arduino\n"
" -r, --receive Receive data from Arduino & print it out\n"
" -n --num=num Send a number as a single byte\n"
" -d --delay=millis Delay for specified milliseconds\n"
"\n"
"Note: Order is important. Set '-b' before doing '-p'. \n"
" Used to make series of actions: '-d 2000 -s hello -d 100 -r' \n"
" means 'wait 2secs, send 'hello', wait 100msec, get reply'\n"
"\n");
}
int main(int argc, char *argv[])
{
int fd = 0;
char serialport[256];
int baudrate = B9600; // default
char buf[256];
int rc,n;
if (argc==1) {
usage();
exit(EXIT_SUCCESS);
}
/* parse options */
int option_index = 0, opt;
static struct option loptions[] = {
{"help", no_argument, 0, 'h'},
{"port", required_argument, 0, 'p'},
{"baud", required_argument, 0, 'b'},
{"send", required_argument, 0, 's'},
{"receive", no_argument, 0, 'r'},
{"num", required_argument, 0, 'n'},
{"delay", required_argument, 0, 'd'}
};
while(1) {
opt = getopt_long (argc, argv, "hp:b:s:rn:d:",
loptions, &option_index);
if (opt==-1) break;
switch (opt) {
case '0': break;
case 'd':
n = strtol(optarg,NULL,10);
usleep(n * 1000 ); // sleep milliseconds
break;
case 'h':
usage();
break;
case 'b':
baudrate = strtol(optarg,NULL,10);
break;
case 'p':
strcpy(serialport,optarg);
fd = serialport_init(optarg, baudrate);
if(fd==-1) return -1;
break;
case 'n':
n = strtol(optarg, NULL, 10);
rc = serialport_writebyte(fd, (uint8_t)n);
if(rc==-1) return -1;
break;
case 's':
strcpy(buf,optarg);
rc = serialport_write(fd, buf);
if(rc==-1) return -1;
break;
case 'r':
serialport_read_until(fd, buf, '\n');
printf("lire: %s\n",buf);
break;
}
}
exit(EXIT_SUCCESS);
}
int serialport_writebyte( int fd, uint8_t b)
{
int n = write(fd,&b,1);
if( n!=1)
return -1;
return 0;
}
int serialport_write(int fd, const char* str)
{
int len = strlen(str);
int n = write(fd, str, len);
if( n!=len )
return -1;
return 0;
}
int serialport_read_until(int fd, char* buf, char until)
{
char b[1];
int i=0;
do {
int n = read(fd, b, 1);
if( n==-1) return -1;
if( n==0 ) {
usleep( 10 * 1000 );
continue;
}
buf[i] = b[0]; i++;
} while( b[0] != until );
buf[i] = 0;
return 0;
}
int serialport_init(const char* serialport, int baud)
{
struct termios toptions;
int fd;
//fprintf(stderr,"init_serialport: ouvre le port %s @ %d bps\n",
// serialport,baud);
fd = open(serialport, O_RDWR | O_NOCTTY | O_NDELAY);
if (fd == -1) {
perror("init_serialport: impossible d'ouvrir le port ");
return -1;
}
if (tcgetattr(fd, &toptions) < 0) {
perror("init_serialport: imposible de recevoir les options du terminal");
return -1;
}
speed_t brate = baud;
switch(baud) {
case 4800: brate=B4800; break;
case 9600: brate=B9600; break;
#ifdef B14400
case 14400: brate=B14400; break;
#endif
case 19200: brate=B19200; break;
#ifdef B28800
case 28800: brate=B28800; break;
#endif
case 38400: brate=B38400; break;
case 57600: brate=B57600; break;
case 115200: brate=B115200; break;
}
cfsetispeed(&toptions, brate);
cfsetospeed(&toptions, brate);
// 8N1
toptions.c_cflag &= ~PARENB;
toptions.c_cflag &= ~CSTOPB;
toptions.c_cflag &= ~CSIZE;
toptions.c_cflag |= CS8;
// no flow control
toptions.c_cflag &= ~CRTSCTS;
toptions.c_cflag |= CREAD | CLOCAL; // turn on READ & ignore ctrl lines
toptions.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
toptions.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
toptions.c_oflag &= ~OPOST; // make raw
toptions.c_cc[VMIN] = 0;
toptions.c_cc[VTIME] = 20;
if( tcsetattr(fd, TCSANOW, &toptions) < 0) {
perror("init_serialport: Couldn't set term attributes");
return -1;
}
return fd;
}
coté arduino c'est un truc simple du genre:
void setup() {
Serial.begin(9600);
Serial.println("test");
}
void loop() {
}
sous mac il n'y a pas de probleme la compilation se deroule normalement et la sortie ressemble à:
- ~>./arduino-serial -p /dev/tty.usbmodem1d11 -r
- read: test
- ~>
Sous linux la compilation marche tout aussi bien mais la sortie me donne:
- ~>./arduino-serial -p /dev/ttyACM0 -r
- read: ?
- ~>
je ne comprend pas d'ou vient ce point d'interogation et pourquoi sa marche sous mac alors que se sont tous deux des systemes unix... 
Est ce que quelqu'un a deja fait face a ce meme probleme? car j'avoue que je ne pas trop comprendre 
