git.defcon.no Git - test-repo/blob - door_works.c

   1 #include <termios.h> /* Terminal I/O support */
   2 #include <errno.h>   /* Error number definitions */
   3 #include <string.h>  /* String function definitions */
   4 #include <stdio.h>   /* Standard I/O */
   5 #include <fcntl.h>   /* File descriptor manipulation */
   6
   7 #define DEVICE "/dev/ttyUSB0"
   8
   9 int open_port ( char* device )
  10 {
  11         int f;
  12         struct termios tio;
  13
  14         f = open ( DEVICE, O_RDWR | O_NOCTTY ); // Not using O_NDELAY, that caused ERR11: temp unavail.
  15         if ( f < 0 )
  16         {
  17                 perror(DEVICE);
  18                 return(-1);
  19         }
  20
  21         // Fixed settings: 9600bps, 8 bits,
  22         // no parity, no flow-control,
  23         // local mode, read enabled
  24         tio.c_cflag = B9600 | CS8 | CLOCAL | CREAD;
  25         tio.c_cflag &= ~CRTSCTS;
  26         tio.c_iflag = IGNPAR;
  27         tio.c_oflag = 0;
  28         tio.c_lflag = 0; // Non-canonical read, no other options.
  29         tio.c_cc[VMIN] = 3; // Expect 3 characters, always.
  30         tio.c_cc[VTIME] = 60; // Wait for a max of 6 seconds
  31
  32         tcsetattr(f,TCSANOW,&tio); // Apply this now.
  33
  34         return f;
  35 }
  36
  37 int send_cmd ( int fd, char cmd )
  38 {
  39         int res;
  40         char buf[7];
  41         char status;
  42
  43         tcflush(fd, TCIFLUSH); // Flush the serial input buffer.
  44
  45         res = write( fd, &cmd , 1 );    // Send the command to the device
  46         if ( res < 0 ) return -1;       // and return on failure.
  47
  48         res = read( fd, buf, 5 );
  49         if ( res < 0 )
  50         {
  51                 printf("SERIAL read error %d: %s\n", errno, strerror(errno));
  52                 return -1;
  53         }
  54         if ( res == 0 )
  55         {
  56                 printf ("Null read\n");
  57                 return -1;
  58         }
  59
  60         buf[res] = 0x00;
  61
  62         // A response is supposed to be precisely three characters.
  63         if ( res != 3 ) {
  64                 return -1;
  65         }
  66
  67         // And the first is supposed to be an echo of the given command.
  68         if ( buf[0] != cmd )
  69         {
  70                 printf("Error: echoed command not correct\n");
  71                 return -1;
  72         }
  73
  74         // The second is (a ':' is ignored, and the third is checked.
  75         // The only valid responses are Locked, Open and Moving.
  76         status = buf[2];
  77
  78         if ( (status == 'O') || (status == 'L') || (status == 'M') )
  79                 return status;
  80         else return -1;
  81 }
  82
  83 int get_state ( int fd )
  84 {
  85         return send_cmd( fd, 's'); // Yashure. KISS
  86 }
  87
  88 int set_state ( int fd, int state )
  89 {
  90         int res;
  91         switch ( state )
  92         {
  93                 case 0:
  94                         res = send_cmd ( fd, 'o');
  95                         break;
  96                 case 1:
  97                         res = send_cmd ( fd, 'l');
  98                         break;
  99         }
 100         if ( (res != 'L') && ( res != 'O' ) ) return -1; // FAIL
 101         // And, yes, I will call a status "Moving" a failed state-change attempt
 102         return 0;
 103 }
 104
 105
 106 int main ( int argc, char** argv )
 107 {
 108         int fd;
 109         int res;
 110         int c;
 111         char buf[255];
 112
 113         fd = open_port( DEVICE );
 114         if ( fd < 0 )
 115         {
 116                 perror(DEVICE);
 117                 return(-1);
 118         }
 119
 120         printf("Enter command character, followed by enter/return\n");
 121         printf("Valid commands are:\n l - Lock\n o - Open \n s - Status\n i - Invalid simulation\n");
 122         printf("ESC Enter exits");
 123         printf("rdy>");
 124         for(;;)
 125         {
 126                 res = getchar();
 127                 if ( res == 10 ) continue;
 128
 129                 if ( res == 27 ) return 1;
 130                 switch( res )
 131                 {
 132                         case 'l':
 133                                 printf("Locking...\n");
 134                                 if ( set_state( fd, 1 ) ) printf ( "set_state() failed\n");
 135                                 break;
 136                         case 'o':
 137                                 printf("Opening...\n");
 138                                 if ( set_state( fd, 0 ) ) printf ( "set_state() failed\n");
 139                                 break;
 140                         case 's':
 141                                 printf("Requesting status...\n");
 142                                 res = get_state( fd );
 143                                 switch ( res )
 144                                 {
 145                                         case 'O':
 146                                                 printf("Open\n");
 147                                                 break;
 148                                         case 'L':
 149                                                 printf("Locked\n");
 150                                                 break;
 151                                         case 'M':
 152                                                 printf("Moving\n");
 153                                                 break;
 154                                         default:
 155                                                 printf("Unknown status %d\n", res);
 156                                 }
 157                                 break;
 158                         case 'i':
 159                                 printf("Sending invalid command...\n");
 160                                 res = send_cmd( fd, (char)res );
 161                                 printf("Back from attempt. Got %d back\n", res);
 162                         default:
 163                                 break;
 164                 }
 165                 printf("rdy>");
 166         }
 167 }
 168
 169