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Libraries \ NMEA

Reference for Wiring version 1.0 Build 0100+ If you have a previous version, use the reference included with your software. If see any errors or have any comments, let us know.

Class | NMEA
Name |

### gprmc_distance_to()

Examples |
    #include <nmea.h>

    NMEA gps(GPRMC);  // GPS data connection to GPRMC sentence type

    // destination coordinates in degrees-decimal
    float dest_latitude = 48.858342;
    float dest_longitude = 2.294522;

    void setup() {
      Serial1.begin(4800);
      pinMode(8, OUTPUT);
    }

    void loop() {
      if (Serial1.available() > 0 ) {
        // read incoming character from GPS
        char c = Serial1.read();

        // check if the character completes a valid GPS sentence
        if (gps.decode(c)) {
          // check if GPS positioning was active
          if (gps.gprmc_status() == 'A') {
            // read distance to destination in meters and set led accordingly
            if (gps.gprmc_distance_to(dest_latitude, dest_longitude, MTR) < 500.0) {
              digitalWrite(8, HIGH);
            } else {
              digitalWrite(8, LOW);
            }
          }
        }
      }
    }
Description | Returns distance of the GPS to a given position. For example, your distance in meters to the Dom Tower in Utrecht (Netherlands), is given by gprmc_distance_to(52.090647, 5.121283, MTR). As units of distance, you can use MTR for meters, KM for kilometers, MI for (international) miles, and NM for nautical miles. Distance is calculated as 'great-circle distance' on a perfect sphere. It does not take into account terrain height variations, and Earth is no perfect sphere. As a result, calculated distance may be slightly off by an estimated maximum of 0.5%.
Syntax |
    gprmc_distance_to(latitude, longitude, unit)
Parameters |

latitude | float
longitude | float
unit | MTR, KM, MI, or NM

Returns | float
Usage | Application

Updated on July 07, 2011 11:11:09pm PDT