GPGSA

src/NmeaParser.Shared/Nmea/Gps/GPGSA.cs

@@ -0,0 +1,105 @@
+//
+// Copyright (c) 2014 Morten Nielsen
+//
+// Licensed under the Microsoft Public License (Ms-PL) (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://opensource.org/licenses/Ms-PL.html
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NmeaParser.Nmea.Gps
+{
+	/// <summary>
+	///  Global Positioning System Fix Data
+	/// </summary>
+	[NmeaMessageType(Type = "GPGSA")]
+	public class Gpgsa : NmeaMessage
+	{
+		public enum ModeSelection
+		{
+			Auto,
+			Manual,
+		}
+		public enum Mode : int
+		{
+			NotAvailable = 1,
+			_2D = 2,
+			_3D = 3
+		}
+
+		protected override void LoadMessage(string[] message)
+		{
+			GpsMode = message[0] == "A" ? ModeSelection.Auto : ModeSelection.Manual;
+			FixMode = (Mode)int.Parse(message[1]);
+
+			List<int> svs = new List<int>();
+			for (int i = 2; i < 14; i++)
+			{
+				int id = -1;
+				if (message[i].Length > 0 && int.TryParse(message[i], out id))
+					svs.Add(id);
+			}
+			SVs = svs.ToArray();
+
+			double tmp;
+			if (double.TryParse(message[14], NumberStyles.Float, CultureInfo.InvariantCulture, out tmp))
+				PDop = tmp;
+			else
+				PDop = double.NaN;
+
+			if (double.TryParse(message[15], NumberStyles.Float, CultureInfo.InvariantCulture, out tmp))
+				HDop = tmp;
+			else
+				HDop = double.NaN;
+
+			if (double.TryParse(message[16], NumberStyles.Float, CultureInfo.InvariantCulture, out tmp))
+				VDop = tmp;
+			else
+				VDop = double.NaN;
+		}
+
+		/// <summary>
+		/// Mode
+		/// </summary>
+		public ModeSelection GpsMode { get; private set; }
+
+		/// <summary>
+		/// Mode
+		/// </summary>
+		public Mode FixMode { get; private set; }
+
+		/// <summary>
+		/// IDs of SVs used in position fix
+		/// </summary>
+		public int[] SVs { get; private set; }
+
+		/// <summary>
+		/// Dilution of precision
+		/// </summary>
+		public double PDop { get; set; }
+
+		/// <summary>
+		/// Horizontal dilution of precision
+		/// </summary>
+		public double HDop { get; set; }
+
+		/// <summary>
+		/// Vertical dilution of precision
+		/// </summary>
+		public double VDop { get; set; }
+	}
+}

src/NmeaParser.Shared/Nmea/NmeaMessage.cs

@@ -48,7 +48,7 @@ namespace NmeaParser.Nmea
 					checksumTest ^= Convert.ToByte(message[i]);
 				}
 				if (checksum != checksumTest)
-					throw new ArgumentException("Invalid nmea message: Checksum failure");
+					throw new ArgumentException(string.Format("Invalid nmea message: Checksum failure. Got {0:X2}, Expected {1:X2}", checksum, checksumTest));
 			}
 
 			string[] parts = message.Split(new char[] { ',' });

src/NmeaParser.Shared/NmeaParser.Shared.projitems

@@ -12,6 +12,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)NmeaDevice.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)NmeaFileDevice.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Nmea\Gps\Garmin\PGRME.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Nmea\Gps\GPGSA.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Nmea\Gps\GPGGA.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Nmea\Gps\GPRMB.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Nmea\Gps\GPRMC.cs" />

src/NmeaParser.Tests/NmeaMessages.cs

@@ -147,5 +147,50 @@ namespace NmeaParser.Tests
 			Assert.AreEqual(4.0, rme.SphericalError);
 			Assert.AreEqual("M", rme.SphericalErrorUnits);			
 		}
+
+		[TestMethod]
+		public void TestGpgsa_Empty()
+		{
+			string input = "$GPGSA,A,3,,,,,,16,18,,22,24,,,,,*14";
+			var msg = NmeaMessage.Parse(input);
+			Assert.IsInstanceOfType(msg, typeof(Gpgsa));
+			Gpgsa gsa = (Gpgsa)msg;
+			Assert.AreEqual(Gpgsa.ModeSelection.Auto, gsa.GpsMode);
+			Assert.AreEqual(Gpgsa.Mode._3D, gsa.FixMode);
+			Assert.AreEqual(4, gsa.SVs.Length);
+			Assert.AreEqual(16, gsa.SVs[0]);
+			Assert.AreEqual(18, gsa.SVs[1]);
+			Assert.AreEqual(22, gsa.SVs[2]);
+			Assert.AreEqual(24, gsa.SVs[3]);
+			Assert.AreEqual(double.NaN, gsa.PDop);
+			Assert.AreEqual(double.NaN, gsa.HDop);
+			Assert.AreEqual(double.NaN, gsa.VDop);
+		}
+		[TestMethod]
+		public void TestGpgsa()
+		{
+			string input = "$GPGSA,M,2,19,28,14,18,27,22,31,39,40,42,43,44,1.7,1.0,1.3*3C";
+			var msg = NmeaMessage.Parse(input);
+			Assert.IsInstanceOfType(msg, typeof(Gpgsa));
+			Gpgsa gsa = (Gpgsa)msg;
+			Assert.AreEqual(Gpgsa.ModeSelection.Manual, gsa.GpsMode);
+			Assert.AreEqual(Gpgsa.Mode._2D, gsa.FixMode);
+			Assert.AreEqual(12, gsa.SVs.Length);
+			Assert.AreEqual(19, gsa.SVs[0]);
+			Assert.AreEqual(28, gsa.SVs[1]);
+			Assert.AreEqual(14, gsa.SVs[2]);
+			Assert.AreEqual(18, gsa.SVs[3]);
+			Assert.AreEqual(27, gsa.SVs[4]);
+			Assert.AreEqual(22, gsa.SVs[5]);
+			Assert.AreEqual(31, gsa.SVs[6]);
+			Assert.AreEqual(39, gsa.SVs[7]);
+			Assert.AreEqual(40, gsa.SVs[8]);
+			Assert.AreEqual(42, gsa.SVs[9]);
+			Assert.AreEqual(43, gsa.SVs[10]);
+			Assert.AreEqual(44, gsa.SVs[11]);
+			Assert.AreEqual(1.7, gsa.PDop);
+			Assert.AreEqual(1.0, gsa.HDop);
+			Assert.AreEqual(1.3, gsa.VDop);
+		}
 	}
 }