root / util / read.c @ master
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <fcntl.h> |
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#include <termios.h> |
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#include <unistd.h> |
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#include <stdio.h> |
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#include <string.h> |
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#define RFID_OK 1 |
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static char read_cmd[] = {'!', 'R', 'W', 1, 32}; |
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static int serno; |
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|
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void init_tty(int fd) { |
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struct termios ios;
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bzero(&ios, sizeof(ios));
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ios.c_cflag = B9600 | CS8 | CREAD; |
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tcsetattr(fd, TCSAFLUSH, &ios); |
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} |
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|
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int bswap(int x) { |
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return ((x&0xff) << 24) | ((x&0xff00) << 8) |
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| ((x>>8) & 0xff00) | ((x>>24) & 0xff); |
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} |
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|
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void read_all(int fd, void *buf, int n) { |
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int nread;
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while (n > 0) { |
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nread = read(fd, buf, n); |
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buf += nread; |
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n -= nread; |
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usleep(10000);
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} |
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} |
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|
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int main(int argc, char **argv) { |
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int fd;
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char status;
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fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY);
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init_tty(fd); |
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while (1) { |
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tcflush(fd, TCIFLUSH); |
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write(fd, read_cmd, sizeof(read_cmd));
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read_all(fd, &status, 1);
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if (status == RFID_OK) {
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read_all(fd, &serno, 4);
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serno = bswap(serno); |
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printf("%08x\n", serno);
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} else {
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printf("error %d\n", (int)(unsigned char)status); |
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} |
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usleep(50000);
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} |
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close(fd); |
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return 0; |
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} |