void GpsStatus.INmeaListener.OnNmeaReceived(long timestamp, string?message)
#endif
{
_isNmeaSupported = true;
if (message != null)
{
NmeaMessage?.Invoke(this, message);
}
}
void ILocationListener.OnLocationChanged(Location location)
{
if (location.Provider != LocationManager.GpsProvider)
{
Accuracy = float.NaN;
return;
}
Accuracy = location.HasAccuracy ? location.Accuracy : float.NaN;
if (_isNmeaSupported)
{
return;
}
// Not all Android devices support reporting NMEA, so we'll fallback to just generating
// simple RMC and GGA message so the provider continues to work across multiple devices
// $GPRMC:
List <string> values = new List <string>(12);
values.Add("$GPRMC");
DateTimeOffset d = DateTimeOffset.FromUnixTimeMilliseconds(location.Time);
values.Add(d.ToString("hhmmss"));
values.Add("A");
var lat = Math.Floor(Math.Abs(location.Latitude));
var latfrac = (Math.Abs(location.Latitude) - lat) * 60;
values.Add($"{lat.ToString("00")}{latfrac.ToString(CultureInfo.InvariantCulture)}");
values.Add(location.Latitude < 0 ? "S" : "N");
var lon = Math.Floor(Math.Abs(location.Longitude));
var lonfrac = (Math.Abs(location.Longitude) - lon) * 60;
values.Add($"{lon.ToString("000")}{lonfrac.ToString(CultureInfo.InvariantCulture)}");
values.Add(location.Longitude < 0 ? "W" : "E");
values.Add(location.HasSpeed ? location.Speed.ToString(CultureInfo.InvariantCulture) : "");
values.Add(location.HasBearing ? location.Bearing.ToString(CultureInfo.InvariantCulture) : "");
values.Add(d.ToString("ddMMyy"));
values.Add(""); //Variation
values.Add(""); //East/West
NmeaMessage?.Invoke(this, string.Join(",", values) + "\n");
// $GPGGA:
int satellites = 0;
if (location.Extras != null && location.Extras.ContainsKey("satellites"))
{
satellites = Convert.ToInt32(location.Extras.Get("satellites"));
}
values = new List <string>(13);
values.Add("$GPGGA");
values.Add(d.ToString("hhmmss"));
values.Add($"{lat.ToString("00")}{latfrac.ToString(CultureInfo.InvariantCulture)}");
values.Add(location.Latitude < 0 ? "S" : "N");
values.Add($"{lon.ToString("000")}{lonfrac.ToString(CultureInfo.InvariantCulture)}");
values.Add(location.Longitude < 0 ? "W" : "E");
values.Add("1"); //Fix Quality:
values.Add(satellites.ToString()); //Number of Satellites
values.Add(""); //HDOP
values.Add(location.HasAltitude ? location.Altitude.ToString(CultureInfo.InvariantCulture) : "");
values.Add("M"); //Altitude units
values.Add(""); //Height of geoid above WGS84 ellipsoid
values.Add(""); //Geoid height units
values.Add(""); //Time since last DGPS update
values.Add(""); //DGPS reference station id
NmeaMessage?.Invoke(this, string.Join(",", values) + "\n");
}