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S'il vous plaît me conseiller. Je voudrais que le code obtienne des données du port série tel que tty/USB0. Donc, besoin de faire ce code lire les données du protocole série comme indiqué ci-dessous.Pourquoi les données de "read" dans le tableau uint8_t ne peuvent pas être récupérées?
uint8_t recBlk; // receive blk from chunk
ret = read(serial_fd, &recBlk, sizeof(recBlk));
printf("Block Num is %d\n", recBlk);
fflush(stdout);
if (ret != sizeof(recBlk)) {
perror("read");
return -errno;
}
Cependant, je ne comprenais pas pourquoi ces lignes ci-dessous montrant ne fonctionne pas, mais l'erreur se produisant « lire: argument non valide »
Comment puis-je obtenir les données du tableau de fonction de lecture?
uint8_t recData[1024]; // receive data from chunk
ret = read(serial_fd, (void *)&recData, sizeof(recData));
printf("Data buffer is %c\n", &recData);
fflush(stdout);
if (ret != sizeof(recData)) {
printf("Can't fetch the Data length!");
perror("read");
return -errno;
}
Ce code montrant ci-dessous est ma fonction d'exécution.
static int xmodem_receive(int serial_fd, char* filename, int _crc, int use_crc){
int skip = 0;
uint8_t sdCRC = 'C'; // Request-To-Send
uint8_t sdACK = X_ACK; //
uint8_t eof = X_EOF;
uint8_t sdNAK = X_NAK;
uint8_t recSTX; // receive SOH from chunk
uint8_t recBlk; // receive blk from chunk
uint8_t recNegBlk; // receive blk negative from chunk
uint8_t recData[1024]; // receive data from chunk
uint16_t recChksum;
uint8_t expected_blkno;
FILE *fp;
int ret, fd;
struct stat stat;
// If we want to receive, We have to send NAK to Sendor.
if (use_crc)
use_crc = MAX_RETRY + 1;
/* Writing as binary */
fp = fopen(filename, "wb");
//Send NAK still read SOH that header of one data chunks
/*
CRC 16
Sending C
Sending NAK
*/
while(use_crc){
char status;
printf("Waiting for sender ping ...");
fflush(stdout);
//
if(_crc){
printf("Send C ping....\n");
ret = write(serial_fd, &sdCRC, sizeof(sdCRC));
}else{
// send NAK before read SOH
printf("Send NAK ping....\n");
ret = write(serial_fd, &sdNAK, sizeof(sdNAK));
} // after sending NAK,receiving SOH from chunk
fflush(stdout);
ret = read(serial_fd, &recSTX, sizeof(recSTX));
if(recSTX == X_STX){
printf("STX is %c\n", &recSTX);
break;
}else{
printf("Garabage payload %c\n", &recSTX);
}
fflush(stdout);
if (ret != sizeof(recSTX)) {
printf("Not working");
fflush(stdout);
perror("read");
return -errno;
}
use_crc--;
}
expected_blkno = 1;
while(ret != EOF){
//So next, receiving blk
ret = read(serial_fd, &recBlk, sizeof(recBlk));
printf("Block Num is %d\n", recBlk);
fflush(stdout);
if (ret != sizeof(recBlk)) {
perror("read");
return -errno;
}
ret = read(serial_fd, &recNegBlk, sizeof(recNegBlk));
printf("Negative Block Num is %d\n", recNegBlk);
fflush(stdout);
if (ret != sizeof(recNegBlk)) {
perror("read");
return -errno;
}
ret = read(serial_fd, (void *)&recData, sizeof(recData));
printf("Data buffer is %c\n", &recData);
fflush(stdout);
if (ret != sizeof(recData)) {
printf("Can't fetch the Data length!");
perror("read");
return -errno;
}
ret = read(serial_fd, &recChksum, sizeof(recChksum));
printf("Check sum is %c", &recChksum);
fflush(stdout);
if (ret != sizeof(recChksum)) {
printf("Can't fetch the Check sum");
perror("read");
return -errno;
}
// data block number check
if(recBlk == 0xff - recNegBlk){
printf("Can't fetch the Block !");
perror("read");
return -errno;
}
// data integrity check
if(recChksum == swap16(crc16(recData, sizeof(recData)))){
perror("read");
return -errno;
}
// check of appended "0xff" from end of data to end of chunk in chunk
unsigned char *ptr = recData;
ptr += sizeof(recData);
while(*ptr == 0xff){
ptr--;
}
fwrite(recData, (ptr - recData),1,fp); // write Datas bytes from our buffer
// set skip flag or end connect
ret = write(serial_fd, &eof, sizeof(uint8_t));
if (ret != sizeof(eof) || ret != sizeof(X_STX)){
return -errno;
}else{
if(ret == X_STX){
skip = 1;
printf("next chunk");
fflush(stdout);
expected_blkno++;
}else if(ret == EOF){
printf("EOF ...");
ret = write(serial_fd, &sdACK, sizeof(sdACK));
break;
}else{
return -errno;
}
}
}
printf("done.\n");
fclose(fp);
return 0;
}
Le réglage terminal est ici.
static int open_serial(const char *path, int baud)
{
int fd;
struct termios tty;
fd = open(path, O_RDWR | O_SYNC);
if (fd < 0) {
perror("open");
return -errno;
}
memset(&tty, 0, sizeof(tty));
if (tcgetattr(fd, &tty) != 0) {
perror("tcgetattr");
return -errno;
}
cfsetospeed(&tty, baud);
cfsetispeed(&tty, baud);
tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8; // 8-bit 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] = 1; // 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 &= ~CSTOPB;
tty.c_cflag &= ~CRTSCTS;
if (tcsetattr(fd, TCSANOW, &tty) != 0) {
perror("tcsetattr");
return -errno;
}
return fd;
}
Peut-être 'serial_fd' n'est pas valide. – user2079303
Pourriez-vous me dire plus comment est-ce mauvais? serial_fd est obtenu à partir de open_serial ("/ dev/ttyUSB0", 115200) de la fonction principale. – NEWBIEEBIEE
Je ne connais pas 'open_serial'. Est-ce une chose raspberrypi? Avez-vous vérifié la valeur de retour, pour s'assurer qu'il a réussi? – user2079303