I'm writing a tracking app for a logistics company, which needs to report the location of each phone back to base on a regular basis. The geolocation.watchPosition method seems ideal, except that as far as I can tell it updates the location as often as once per second with seemingly no way to increase the interval between callbacks. Once per second is a little too often from a data usage point of view - once per minute would be ideal.
Is there an option I can pass to watchPosition to make it execute the callback with a minimum interval?
You could allow it to still call watchPosition once per second, but then separate out the reporting back to base into a separate callback that is run once per minute on a timer.
e.g.:
var GPSStore = {};
navigator.geolocation.watchPosition(
function(current_location) {
// Just store the latest co-ordinates in memory as often as they are generated
GPSStore.location = current_location;
}
);
// Once a minute transmit the latest co-ordinates
setInterval(function() {
transmitLocation(GPSStore.location);
}, 1000*60);