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/* Compile with:
gcc -o clear_rts clear_rts.c
Change PORT if necessary.
*/
#define PORT "/dev/ttyUSB0"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <linux/serial.h>
int main(int argc, char **argv) {
int fd, status;
char *port;
if(argc == 2)
port = argv[1];
else
port = PORT;
fd = open(PORT, O_RDWR);
if(fd < 0) {
perror(PORT);
return 1;
}
ioctl(fd, TIOCMGET, &status);
/* This always says it was on. Opening the port sets it? */
/*
fprintf(stderr, "%s: RTS was ", port);
if(status & TIOCM_RTS) {
fputs("on", stderr);
} else {
fputs("already off", stderr);
}
fputc('\n', stderr);
*/
status &= ~TIOCM_RTS;
ioctl(fd, TIOCMSET, &status);
fprintf(stderr, "%s: RTS forced off (Tucker SIO2PC)\n", port);
return 0;
}
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