C++ (Cpp) lib_fp_stringtolong Examples

Example #1

File: gps.cpp Project: brewpoo/multifly

fixedpointnum gpsstringtoangle(char *string) {
    // takes a gps string and converts it to a fixedpointnum angle
    // "4807.123" means 48 degrees, 7.123 minutes, south
    // how many digits are there before the decimal point?
    int index=0;
    while (string[index]>='0' && string[index]<='9') ++index;

    // convert the minutes part.  Use two digits before the decimal and 7 digits after
    fixedpointnum minutes=0;
    char *ptr=&string[index]-2;
    for (int count=0;count<10;++count) {
        if (*ptr=='.') {
            ++ptr;
        } else {
            minutes*=10;
            if (*ptr) minutes+=(*ptr++) - '0';
        }
    }
    string[index-2]='\0';
    fixedpointnum degrees=lib_fp_stringtolong(string);

    return((degrees<<(FIXEDPOINTSHIFT+LATLONGEXTRASHIFT))+(lib_fp_multiply(minutes,117281L)>>8));  // 29318L is (2^16 * 2^6 * 2^16 * 2^6)/(60 * 10^7)
}

Example #2

File: gps.cpp Project: sbstnp/bradwii_arduino

char readgps()
   {
   while (lib_serial_numcharsavailable(GPS_SERIAL_PORT))
      {
      char c=lib_serial_getchar(GPS_SERIAL_PORT);

      if (c=='$') // start of a new message
         {
         gpsparameternumber=0;
         gpsdataindex=0;
         gpschecksum=0;
         gpsframetype=0;
         }
      else
         {
         if (c==',' || c=='*')
            { // we just finished loading a parameter, interpret it
            gpsdata[gpsdataindex]='\0';

            if (gpsparameternumber == 0) 
               { //frame identification
               if (gpsdata[0] == 'G' && gpsdata[1] == 'P' && gpsdata[2] == 'G' && gpsdata[3] == 'G' && gpsdata[4] == 'A') gpsframetype=FRAME_GGA;
               else if (gpsdata[0] == 'G' && gpsdata[1] == 'P' && gpsdata[2] == 'R' && gpsdata[3] == 'M' && gpsdata[4] == 'C') gpsframetype = FRAME_RMC;
               } 
            else if (gpsframetype == FRAME_GGA) 
               {
               if (gpsparameternumber == 2) 
                  {
                  gpslatitudedegrees = gpsstringtoangle(gpsdata);
                  }
               else if (gpsparameternumber == 3)
                  {
                  if ( gpsdata[0] == 'S') gpslatitudedegrees=-gpslatitudedegrees;
                  }
               else if (gpsparameternumber == 4)
                  {
                  gpslongitudedegrees = gpsstringtoangle(gpsdata);
                  }
               else if (gpsparameternumber == 5)
                  {
                  if ( gpsdata[0] == 'W') gpslongitudedegrees=-gpslongitudedegrees;
                  }
               else if (gpsparameternumber == 6)
                  {
                  gpsfix = gpsdata[0]-'0';
                  }
               else if (gpsparameternumber == 7)
                  {
                  global.gps_num_satelites = lib_fp_stringtolong(gpsdata);
                  }
               else if (gpsparameternumber == 9)
                  {
                  global.gps_current_altitude = lib_fp_stringtofixedpointnum(gpsdata);
                  }
               } 
            else if (gpsframetype == FRAME_RMC) 
               {
               if (gpsparameternumber == 7)
                  {
                  // 1 knot = 0.514444444 m / s
                  global.gps_current_speed=lib_fp_multiply(lib_fp_stringtofixedpointnum(gpsdata),33715L); // 33715L is .514444444 * 2^16
                  }
               else if (gpsparameternumber == 8) 
                  {
//                  GPS_ground_course = grab_fields(gpsdata,1); 
                  }                 //ground course deg*10 
               }
            
            ++gpsparameternumber;
            gpsdataindex = 0; // get read for the next parameter
            if (c == '*') gpsfinalchecksum=gpschecksum;
            }
         else if (c == '\r' || c == '\n') 
            { // end of the message
            unsigned char checksum = hextochar(gpsdata[0]);
            checksum <<= 4;
            checksum += hextochar(gpsdata[1]);

            if (checksum != gpsfinalchecksum || gpsframetype!=FRAME_GGA || !gpsfix) return(0);
            gpsframetype=0; // so we don't check again

            global.gps_current_latitude=gpslatitudedegrees;
            global.gps_current_longitude=gpslongitudedegrees;
            
            return(1); // we got a good frame
            }
         else if (gpsdataindex<GPSDATASIZE)
            {
            gpsdata[gpsdataindex++]=c;
            }
         gpschecksum^=c;
         }
      }
   return(0); // no complete data yet
   }