//=======================================================================
//=======================================================================
public static bool TryParse(string inputString, out GsvData gsvData)
{
try
{
gsvData = Parse(inputString);
return(true);
}
catch
{
gsvData = 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 GsvData Parse(string inputString)
{
//---- declare vars
GsvData data = new GsvData();
string dataString = inputString.Substring(0, inputString.IndexOf('*')); // strip off the checksum
string[] values = dataString.Split(',');
//---- if we don't have 20 (header + 19), it's no good
if (values.Length < 20)
{
return(data);
}
//---- number of messages
data.MessageCount = int.Parse(values[1]);
//---- message number
data.MessageNumber = int.Parse(values[2]);
//---- total number of satellites in view
data.SatellitesInView = int.Parse(values[3]);
//---- loop through the satellites (up to 4)
for (int i = 0; i < 4; i++)
{
//---- create a new satellite
Satellite sat = new Satellite();
//---- satellite information starts at index 4, goes for 4 lines, and then starts over (4-7), (8-11), (12-15), (16-19)
int satIndex = (4 + (4 * i));
//---- satellite ID
sat.ID = (string.IsNullOrEmpty(values[satIndex]) ? 0 : int.Parse(values[satIndex]));
//---- if we got a satellite
if (sat.ID > 0)
{
//---- elevation
sat.AngleOfElvation = (string.IsNullOrEmpty(values[satIndex + 1]) ? 0 : int.Parse(values[satIndex + 1]));
//---- azimuth
sat.Azimuth = (string.IsNullOrEmpty(values[satIndex + 2]) ? 0 : int.Parse(values[satIndex + 2]));
//---- signal strength
sat.SignalStrength = (string.IsNullOrEmpty(values[satIndex + 3]) ? 0 : int.Parse(values[satIndex + 3]));
//---- used in fix? [TODO: Verify this assumption of signal 00 is all right]
if (sat.SignalStrength > 0)
{
sat.UsedInPositionFix = true;
}
else
{
sat.UsedInPositionFix = false;
}
//---- add the sat
data.Satellites.Add(sat);
}
}
//---- return
return(data);
//$GPGSV,1,1,13,02,02,213,,03,-3,000,,11,00,121,,14,13,172,05*67
//1 = Total number of messages of this type in this cycle
//2 = Message number
//3 = Total number of SVs in view
//4 = SV PRN number
//5 = Elevation in degrees, 90 maximum
//6 = Azimuth, degrees from true north, 000 to 359
//7 = SNR, 00-99 dB (null when not tracking)
//8-11 = Information about second SV, same as field 4-7
//12-15= Information about third SV, same as field 4-7
//16-19= Information about fourth SV, same as field 4-7
}
