Wie lese ich Binärdaten über ein serielles Terminal in einem C-Programm?
Ich habe die folgenden Links und andere Quellen gelesen, aber keine Antwort auf meine Frage gefunden.
Binärdaten über serielles Terminal
Daten werden während der Übertragung über die serielle Schnittstelle beschädigt
Ich kommuniziere mit meinem eingebetteten Gerät über eine serielle Schnittstelle. Standardmäßig verwendet Embedded Linux diesen Port als Terminal. Ich möchte aber auch binäre Daten (Service-Pakete) über den Port übertragen. Meine / etc / inittab-Datei hat einen "getty" -Aufruf:console :: respawn: / sbin / getty 115200 ttyS0
Ich habe auch die Datei / etc / passwd mit der Zeichenfolge, in der der Benutzer "admin" nach dem Anmelden die Anwendung "cli" startet:admin: 8Mt / Jtxcyg8AY: 1000: 0: admin: / tmp: / tmp / cli
Meine Standardeinstellungen für ttyS0 vor dem Ausführen des Programms sind:
~ # stty -a
speed 115200 baud;stty: standard input
line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = ^J;
eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R;
werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon ixoff
-iuclc -ixany -imaxbel -iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon -iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
-echoctl echoke
~ #
Also mache ich in meinem Cli-Programm Folgendes:
main ()
{
...
system("stty erase ^H);
system("stty -F /dev/ttyS0 -icrnl -ixon -ixoff -opost -isig -icanon -echo"); // enter in non-canonical (raw) mode
// What function do I need to use here to retrieve binary data (also symbols that > 0x7F) from /dev/ttyS0?
system("stty -F /dev/ttyS0 icrnl ixon ixoff opost isig icanon echo"); // go back to canonical mode
...
exit(0);
}
Ich habe versucht, die Funktion read () (mit vorzeichenlosem Zeichenpuffer) zum Abrufen von Binärdaten zu verwenden, konnte jedoch keine korrekten Daten empfangen. Ich öffne auch vorläufig / dev / ttyS0 erneut, um file_descriptor abzurufen und benutze read () func.
Mein Programm sendet 3 Bytes: 0xAA, 0x02, 0xFE. Aber im Syslog sehe ich immer, dass das Gerät falsche Symbole empfängt: 0x98, 0xE6, 0x18.
Was ist da los? Wie bekomme ich korrekte Binärdaten?
Ein ganzer Code, den ich gerade teste.
#include "cli.h"
#include "glb_vars.h"
/******************************************
*** Definitions
******************************************/
#define APPLICATION_NAME "cli"
#define SERIALPORT_IS_CONSOLE
/******************************************
*** Constants
******************************************/
const char dev_name[] = DEV_NAME;
const char lineminstr[] = "\t--------------------------------------------------------\n";
/******************************************
*** Internal Function Declarations
******************************************/
CLI_RETVAL cliInit(void);
CLI_RETVAL cliClose(void);
void cliWorkLoop(Term_callback_t **term);
/******************************************
*** External Function Declarations
******************************************/
extern void Vectors_init(Term_callback_t **vec);
extern char** Menu_completion(const char * text, int start, int end);
/****************************************************************************/
int file_descr, max_fd;
struct termios tty, orig_tty;
fd_set work_set;
/****************************************************************************/
/*!
* \brief Init cli
*
* \return success or failure
* \retval CLI_SUCCESS, CLI_FAILURE
*
* \ingroup CLI
*/
/****************************************************************************/
CLI_RETVAL cliInit(void)
{
long spd;
signal(SIGINT, SIG_IGN);
signal(SIGHUP, SIG_IGN);
signal(SIGTERM, SIG_IGN);
signal(SIGABRT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGILL, SIG_IGN);
// system("stty -F /dev/ttyS0 -icrnl -ixon -ixoff -opost -isig -icanon -echo"); // enter in non-canonical mode
// system("stty -a");
// sleep(1);
#ifdef SERIALPORT_IS_CONSOLE
file_descr = STDIN_FILENO;
SYS_LOG_DEBUG("SERIALPORT IS CONSOLE");
#else
SYS_LOG_DEBUG("SERIALPORT IS NOT CONSOLE");
file_descr = open("/dev/ttyS0", O_RDWR | O_ASYNC | O_NDELAY);
if (file_descr == -1) {
// Could not open the port
perror("unable to open /dev/ttyS0");
exit(1);
}
#endif
if(tcgetattr(file_descr, &tty) < 0)
{
perror("unable to get tty attributes");
exit(1);
}
// backup tty, make it raw and apply changes
orig_tty = tty;
spd = B115200;
cfsetospeed(&tty, (speed_t)spd);
cfsetispeed(&tty, (speed_t)spd);
cfmakeraw(&tty);
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 10;
tty.c_cflag &= ~CSTOPB;
tty.c_cflag &= ~CRTSCTS; /* no HW flow control? */
tty.c_cflag |= CLOCAL | CREAD;
tcsetattr(file_descr, TCSANOW, &tty);
// // update local mode flags
// tty.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
//// // renew control mode flags
//// tty.c_cflag &= ~(CBAUD | CSIZE | CSTOPB | PARENB | PARODD);
//// tty.c_cflag |= (BAUD | DATABITS | STOPBITS | PARITYON | PARITY);
// // select 'raw' output mode
// tty.c_oflag &= ~OPOST;
// // disable mapping for input mode
// tty.c_iflag &= ~(INLCR | ICRNL);
//
//
// if(tcsetattr(file_descr, TCSAFLUSH, &tty) < 0)
// {
// perror("unable to set tty attributes");
// exit(1);
// }
//
// Setup fd_set
FD_ZERO(&work_set);
FD_SET(file_descr, &work_set);
max_fd = file_descr + 1;
/* Readline lib init */
// Define application name for readline library
rl_readline_name = APPLICATION_NAME;
// Update Pointer to alternative function to create matches.
rl_attempted_completion_function = Menu_completion;
// Start readline with reading /etc/inputrc file
using_history();
stifle_history(CLI_MAX_HISTORY_SIZE);
// Some other initialization code
// ...
// ...
return CLI_SUCCESS;
}
/****************************************************************************/
/*!
* \brief Close cli
*
* \return success or failure
* \retval CLI_SUCCESS, CLI_FAILURE
*
* \ingroup CLI
*/
/****************************************************************************/
CLI_RETVAL cliClose(void)
{
// system("stty -F /dev/ttyS0 icrnl ixon ixoff opost isig icanon echo"); // enter in canonical mode
tcsetattr(file_descr, TCSANOW, &orig_tty);
// if(tcsetattr(file_descr, TCSAFLUSH, &orig_tty) < 0)
// {
// perror("unable to set orig_tty attributes");
// exit(1);
// }
close(file_descr);
return CLI_SUCCESS;
}
/****************************************************************************/
/*!
* \brief Main cli processing loop
*
* \no return
*
* \ingroup CLI
*/
/****************************************************************************/
void cliWorkLoop(Term_callback_t **term)
{
Term_callback_t *cur_term;
int8 *commandString;
uint8 ret = CLI_REFRESH, no_prompt;
char prompt_str[20];
while (1) {
cur_term = *term;
global_cmd_compl_pointer = cur_term->cmd_list;
commandString = NULL;
sprintf(prompt_str, "%s:~> ", dev_name);
if(ret == CLI_REFRESH) {
CLEAR_SCR();
if(cur_term->out != NULL) {
cur_term->out(term, commandString, &ret);
no_prompt = ret;
}
CURSOR_DOWN();
}
int n;
struct timeval timeout;
uint8 tmpBuf[32];
while (1)
{
// Setup Timeout
timeout.tv_sec = 60;
timeout.tv_usec = 0;
// Wait for new connections
n = select(max_fd, &work_set, NULL, NULL, &timeout);
if (n < 0)
{
perror("select #2 failed");
break;
}
if (n > 0)
{
/* У нас есть ввод */
if (FD_ISSET(file_descr, &work_set))
{
if (read(file_descr, tmpBuf, 10) < 0) {
perror("cannot read");
exit(1);
}
else
{
SYS_LOG_DEBUG("READ first 4 chars: 0x%X,0x%X,0x%X,0x%X", tmpBuf[0], tmpBuf[1], tmpBuf[2], tmpBuf[3]);
}
}
break;
}
}
//
//
// n = read(file_descr, tmpBuf, 5);
// if (n > 0) {
// unsigned char *p = tmpBuf;
//
// while (n-- > 0)
// printf(" 0x%x", *p++);
// printf("\r\n");
// } else {
// printf("failed to read: %d\r\n", n);
// }
//
//
exit(0);
}
CLEAR_SCR();
return;
}
/****************************************************************************/
/*!
* \brief Main cli function
*
* \param[in] argc - argument number.
* \param[in,out] argv - argument values entered by user.
*
* \return success or failure
* \retval EXIT_SUCCESS, EXIT_FAILURE
*
*
* \ingroup CLI
*/
/****************************************************************************/
int main(int argc, char *argv[])
{
Term_callback_t *term;
char logname[16];
FILE *fp;
/* Set mask for file operation */
umask(0);
system("stty erase ^H");
openlog("cli", LOG_CONS, LOG_USER);
/* Write cli start log */
syslog(LOG_NOTICE, "Console startup. Software version: %s", VERSION);
/* Find login name */
strcpy(logname, "noname");
if ((fp = popen( "whoami", "r" )) == NULL)
{
SYS_LOG_ERR("Can't open process for \"whoami\" command.");
} else
{
fgets(logname, 16, fp);
pclose(fp);
}
SYS_LOG_INFO("Console is entered by \"%s\".", logname); //getenv("USER")
/* Console initialization */
if (cliInit() != CLI_SUCCESS) {
SYS_LOG_CRIT("CLI init failed");
return EXIT_FAILURE;
}
Vectors_init(&term);
/* Console work loop */
cliWorkLoop(&term);
cliClose();
/* Exiting from cli */
SYS_LOG_INFO("\"%s\" exited from console.", logname);
return EXIT_SUCCESS;
}