//=======================================================================
//=======================================================================
public static bool TryParse(string inputString, out GsaData gsaData)
{
try
{
gsaData = Parse(inputString);
return(true);
}
catch
{
gsaData = null;
return(false);
}
}
//=======================================================================
//=======================================================================
private static GpsReading ParseSentences(string[] sentences)
{
//---- declare vars
GpsReading gpsReading = new GpsReading();
//---- loop through each sentence
for (int i = 0; i < sentences.Length; i++)
{
//---- if the sentence has a header and data
if (sentences[i].Length > 6)
{
switch (sentences[i].Trim().Substring(0, 6).ToUpper())
{
case "$GPGSA":
gpsReading.DopActiveSatellites = GsaData.Parse(sentences[i]);
break;
case "$GPGSV":
gpsReading.SatellitesInView.Add(GsvData.Parse(sentences[i]));
break;
case "$GPGGA":
gpsReading.FixedGpsData = GgaData.Parse(sentences[i]);
break;
case "$GPRMC":
gpsReading.Summary = RmcData.Parse(sentences[i]);
break;
case "$GPMSS":
break;
case "$GPVTG":
break;
}
}
}
//---- return our parsed gps reading
return(gpsReading);
}
//=======================================================================
#region -= static methods =-
//=======================================================================
public static GsaData Parse(string inputString)
{
//---- declare vars
GsaData data = new GsaData();
string dataString = inputString.Substring(0, inputString.IndexOf('*')); // strip off the checksum
string[] values = dataString.Split(',');
//---- if we don't have 18 (header + 17), it's no good
if (values.Length < 18)
{
throw new FormatException();
}
//---- mode
data.FixMode = FixModeUtil.Parse(values[1]);
//---- fix type
data.FixType = (FixType)int.Parse(values[2]);
//---- loop through the satellites (3-14)
for (int i = 3; i < 15; i++)
{
if (!string.IsNullOrEmpty(values[i]))
{
//---- create a new satellite
Satellite sat = new Satellite();
//---- these we don't know, so set to -1/false
sat.AngleOfElvation = -1;
sat.Azimuth = -1;
sat.SignalStrength = -1;
sat.UsedInPositionFix = false;
//---- get the satellite ID
sat.ID = int.Parse(values[i]);
//---- add the sat to the collection
data.SatellitesUsed.Add(sat);
}
}
try
{
//---- PDOP
data.DilutionOfPrecision = decimal.Parse(values[15]);
//---- HDOP
data.HorizontalDilutionOfPrecision = decimal.Parse(values[16]);
//---- VDOP
data.VerticalDilutionOfPrecision = decimal.Parse(values[17]);
}
catch (FormatException e)
{
}
//---- return
return(data);
//GPS DOP and active satellites
//eg1. $GPGSA,A,3,,,,,,16,18,,22,24,,,3.6,2.1,2.2*3C
//eg2. $GPGSA,A,3,19,28,14,18,27,22,31,39,,,,,1.7,1.0,1.3*35
//1 = Mode:
// M=Manual, forced to operate in 2D or 3D
// A=Automatic, 3D/2D
//2 = Mode:
// 1=Fix not available
// 2=2D
// 3=3D
//3-14 = IDs of SVs used in position fix (null for unused fields)
//15 = PDOP
//16 = HDOP
//17 = VDOP
}
