GPS 

Example

: Cold Start vs. Hot Start

This example shows the different time for connecting to satellites using ephemeris.

File:
"WaspGPS_3_coldStartvsHotStart.pde"

Code

/*
 *  ------Waspmote GPS Cold Start versus Hot Start Example--------
 *
 *  Explanation: This example shows the different time for connecting to
 *  satellites using ephemeris.
 *
 *  Copyright (C) 2009 Libelium Comunicaciones Distribuidas S.L.
 *  http://www.libelium.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 * 
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Version:           0.1
 *  Design:            David Gascón
 *  Implementation:    Alberto Bielsa
 */

void setup(){
  
  //setup for Serial port
  USB.begin();
 
  // setup the GPS module
  USB.println("Setting up GPS...");
  
  // Inits SD pins
  SD.begin();
  
  // Power SD up
  SD.setMode(SD_ON);
  
  // Turn GPS on
  GPS.ON();
   
}

long time=0;

void loop(){

  USB.println("Initializing SD Card");
  USB.println(SD.init());

  // GPS does not connect to sats yet
  USB.print("GPS Time, Date: ");
  USB.println(GPS.timeGPS);
  USB.println(GPS.dateGPS);
  time=millis();
  // while GPS does not connect to sats, do nothing
  while(!GPS.check()); 
  time=millis()-time;
  USB.print("Time elapsed without ephemeris: ");
  USB.println(time,DEC);

  // store ephemeris in "file_ephemeris.txt"
  if(GPS.saveEphems()){
    USB.println("Ephemeris stored succesfully");
    GPS.OFF();
    delay(15000);
    USB.println("Turning GPS on");
    GPS.ON();
    time=millis();
    if(GPS.loadEphems()) USB.println("Ephemeris loaded succesfully");
    else USB.println("Ephemeris load failed");
    while(!GPS.check());
    time=millis()-time;
    USB.print("Time elapsed with ephemeris: ");
    USB.println(time,DEC);
  }
  else USB.println("Ephemeris save failed");
  SD.close();
  delay(5000);
  
}
    

Download code

You can download the code of this example.