/* * send.c * * A program to communicate with an RCX. * * Under IRIX, Linux, and Solaris, you should be able to compile this * program with cc send.c -o send. I don't know about other versions of * Unix, although I'd be interested in hearing about compatibility issues * that you are able to fix. * * Set DEFAULTTTY to the serial device you want to use. * Set the RCXTTY environment variable to override DEFAULTTTY. * * Some additional documentation is available at: * * http://graphics.stanford.edu/~kekoa/rcx/tools.html * * Acknowledgements: * * Ray Kelm sent word that send.c compiles successfully under Linux, * and he passed on info about the names of the serial devices. * * Laurent Demailly ran this through lint, and suggested some changes, * including a printf bug fix. He also pointed out some behavior * that prompted me to increase the number of retries in the send * code. He also pointed out that this program compiles fine under * Solaris. * * Other people have used the ideas in this program (and Paul Haas's * Perl script) to write similar programs in other languages. More * information is available at http://www.crynwr.com/lego-robotics/. */ /* Copyright (C) 1998, Kekoa Proudfoot. All Rights Reserved. * * License to copy, use, and modify this software is granted provided that * this notice is retained in any copies of any part of this software. * * The author makes no guarantee that this software will compile or * function correctly. Also, if you use this software, you do so at your * own risk. * * Kekoa Proudfoot * kekoa@graphics.stanford.edu * 10/3/98 */ #include #include #include #include #include #include #include #include #include #include #ifdef LINUX #define DEFAULTTTY "/dev/ttyS0" /* Linux - COM1 */ #else #define DEFAULTTTY "/dev/ttyd2" /* IRIX - second serial port */ #endif #define BUFFERSIZE 4096 #define RETRIES 5 /* Hexdump routine */ #define LINE_SIZE 16 #define GROUP_SIZE 4 #define UNPRINTABLE '.' void hexdump(void *buf, int len) { unsigned char *b = (unsigned char *)buf; int i, j, w; for (i = 0; i < len; i += w) { w = len - i; if (w > LINE_SIZE) w = LINE_SIZE; printf("%04x: ", i); for (j = 0; j < w; j++, b++) { printf("%02x ", *b); if ((j + 1) % GROUP_SIZE == 0) putchar(' '); } #if 0 b -= w; for ( ; j < LINE_SIZE; j++) { putchar(' '); putchar(' '); putchar(' '); if ((j + 1) % GROUP_SIZE == 0) putchar(' '); } for (j = 0; j < w; j++, b++) { putchar(isprint(*b) ?(*b) : UNPRINTABLE); } #endif putchar('\n'); } } int rcx_init(char *tty) { int fd; struct termios ios; if ((fd = open(tty, O_RDWR)) < 0) { perror("open"); exit(1); } if (!isatty(fd)) { close(fd); fprintf(stderr, "%s: not a tty\n", tty); exit(1); } memset(&ios, 0, sizeof(ios)); ios.c_cflag = CREAD | CLOCAL | CS8 | PARENB | PARODD; cfsetispeed(&ios, B2400); cfsetospeed(&ios, B2400); if (tcsetattr(fd, TCSANOW, &ios) == -1) { perror("tcsetattr"); exit(1); } return fd; } void rcx_close(int fd) { close(fd); } int rcx_send(int fd, unsigned char *sbuf, int slen, unsigned char *rbuf, int rlen) { unsigned char tbuf[BUFFERSIZE]; unsigned char vbuf[BUFFERSIZE]; unsigned char *sp = sbuf; struct timeval tv; fd_set fds; int tlen = 0, vlen, vpos, rpos; int sum = 0, retry, returnval, count; tbuf[tlen++] = 0x55; tbuf[tlen++] = 0xff; tbuf[tlen++] = 0x00; while (slen--) { tbuf[tlen++] = *sp; tbuf[tlen++] = (~*sp) & 0xff; sum += *sp++; } tbuf[tlen++] = sum; tbuf[tlen++] = ~sum; for (retry = 0; retry < RETRIES; retry++) { if (write(fd, tbuf, tlen) != tlen) { perror("write"); exit(1); } vlen = 0; while (1) { FD_ZERO(&fds); FD_SET(fd, &fds); tv.tv_sec = 0; tv.tv_usec = 300000; if (select(FD_SETSIZE, &fds, NULL, NULL, &tv) == -1) { perror("select"); exit(1); } if (!FD_ISSET(fd, &fds)) break; if ((count = read(fd, &vbuf[vlen], BUFFERSIZE - vlen)) == -1) { perror("read"); exit(1); } vlen += count; } /* Check echo */ returnval = -2; if (vlen < tlen) continue; /* retry */ for (vpos = 0; vpos < tlen; vpos++) if (tbuf[vpos] != vbuf[vpos]) break; if (vpos < tlen) continue; /* retry */ /* Check reply */ returnval = 0; if (vpos == vlen) continue; returnval = -1; if (vlen - vpos < 5) break; /* could continue instead */ if (vbuf[vpos++] != 0x55) break; /* could continue instead */ if (vbuf[vpos++] != 0xff) break; /* could continue instead */ if (vbuf[vpos++] != 0x00) break; /* could continue instead */ for (sum = 0, rpos = 0; vpos < vlen - 2; vpos += 2, rpos++) { if (vbuf[vpos] != ((~vbuf[vpos+1]) & 0xff)) break; sum += vbuf[vpos]; if (rpos < rlen) rbuf[rpos] = vbuf[vpos]; } if (vpos != vlen - 2) break; /* could continue instead */ if (vbuf[vpos] != ((~vbuf[vpos+1]) & 0xff)) break; /* could continue instead */ if ((sum & 0xff) != vbuf[vpos]) break; /* could continue instead */ return rpos; } return returnval; } int main (int argc, char **argv) { unsigned char sendbuf[BUFFERSIZE]; unsigned char recvbuf[BUFFERSIZE]; unsigned char *sp = sendbuf; char *tty; int len; int fd; int i; /* Print usage if nothing on command line */ if (argc == 1) { fprintf(stderr, "usage: %s byte [byte ...]\n", argv[0]); exit(1); } /* Open the serial port */ if ((tty = getenv("RCXTTY")) == NULL) tty = DEFAULTTTY; fd = rcx_init(tty); /* Assemble the message */ for (i = 1; i < argc; i++) { *sp++ = strtol(argv[i], NULL, 16); } /* Send it */ len = rcx_send(fd, sendbuf, sp - sendbuf, recvbuf, BUFFERSIZE); /* Close the tty */ rcx_close(fd); /* Print response and exit */ if (len == -2) { fprintf(stderr, "%s: Bad link.\n", argv[0]); exit(4); } if (len == -1) { fprintf(stderr, "%s: Bad response.\n", argv[0]); exit(2); } if (len == 0) { fprintf(stderr, "%s: No response.\n", argv[0]); exit(3); } if (len > BUFFERSIZE) { fprintf(stderr, "%s: Response too large.\n", argv[0]); exit(5); } hexdump(recvbuf, len); return 0; }