From 2e227a65d88ec652c5011a171cd9297fac4be75d Mon Sep 17 00:00:00 2001
From: The6P4C <watsonjcampbell@gmail.com>
Date: Fri, 29 Sep 2017 18:11:24 +1000
Subject: [PATCH] Add NMEA device support
---
GPSDOTimeSync/FormMain.cs | 12 ++
GPSDOTimeSync/GPSDOTimeSync.csproj | 3 +
.../TimeProviders/NMEA/NMEASerialPort.cs | 168 ++++++++++++++++++
.../TimeProviders/NMEA/NMEATimeProvider.cs | 50 ++++++
4 files changed, 233 insertions(+)
create mode 100644 GPSDOTimeSync/TimeProviders/NMEA/NMEASerialPort.cs
create mode 100644 GPSDOTimeSync/TimeProviders/NMEA/NMEATimeProvider.cs
diff --git a/GPSDOTimeSync/FormMain.cs b/GPSDOTimeSync/FormMain.cs
index d7f1f83..1b08e56 100644
--- a/GPSDOTimeSync/FormMain.cs
+++ b/GPSDOTimeSync/FormMain.cs
@@ -6,6 +6,9 @@ using System.Windows.Forms;
using GPSDOTimeSync.Devices.Thunderbolt;
using GPSDOTimeSync.TimeProviders;
using GPSDOTimeSync.TimeProviders.Thunderbolt;
+using GPSDOTimeSync.TimeProviders.NMEA;
+using System.Diagnostics;
+using System.Linq;
namespace GPSDOTimeSync {
public partial class FormMain : Form {
@@ -22,6 +25,15 @@ namespace GPSDOTimeSync {
ThunderboltSerialPort thunderboltSerialPort = new ThunderboltSerialPort(serialPort);
ITimeProvider timeProvider = new ThunderboltTimeProvider(thunderboltSerialPort);
+ return timeProvider;
+ })
+ },
+ {
+ "NMEA Device (e.g. BG7TBL GPSDO)",
+ new Func<SerialPort, ITimeProvider>((serialPort) => {
+ NMEASerialPort nmeaSerialPort = new NMEASerialPort(serialPort);
+ ITimeProvider timeProvider = new NMEATimeProvider(nmeaSerialPort);
+
return timeProvider;
})
}
diff --git a/GPSDOTimeSync/GPSDOTimeSync.csproj b/GPSDOTimeSync/GPSDOTimeSync.csproj
index b773ba5..00e428f 100644
--- a/GPSDOTimeSync/GPSDOTimeSync.csproj
+++ b/GPSDOTimeSync/GPSDOTimeSync.csproj
@@ -56,6 +56,8 @@
<Compile Include="Properties\AssemblyInfo.cs" />
<Compile Include="SystemTimeUtils.cs" />
<Compile Include="TimeProviders\ITimeProvider.cs" />
+ <Compile Include="TimeProviders\NMEA\NMEASerialPort.cs" />
+ <Compile Include="TimeProviders\NMEA\NMEATimeProvider.cs" />
<Compile Include="TimeProviders\Thunderbolt\ThunderboltSerialPort.cs" />
<Compile Include="TimeProviders\Thunderbolt\ThunderboltTimeProvider.cs" />
<EmbeddedResource Include="FormMain.resx">
@@ -83,6 +85,7 @@
<ItemGroup>
<None Include="App.config" />
</ItemGroup>
+ <ItemGroup />
<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
<!-- To modify your build process, add your task inside one of the targets below and uncomment it.
Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/GPSDOTimeSync/TimeProviders/NMEA/NMEASerialPort.cs b/GPSDOTimeSync/TimeProviders/NMEA/NMEASerialPort.cs
new file mode 100644
index 0000000..ae63935
--- /dev/null
+++ b/GPSDOTimeSync/TimeProviders/NMEA/NMEASerialPort.cs
@@ -0,0 +1,168 @@
+using System;
+using System.Collections.Generic;
+using System.IO.Ports;
+using System.Text;
+using System.Threading;
+
+namespace GPSDOTimeSync.TimeProviders.NMEA {
+ public class NMEASentence {
+ /// <summary>
+ /// The validity of the NMEA sentence.
+ /// If <code>false</code>, the values of <code>Talker</code>, <code>MessageType</code>, <code>Data</code>, <code>Checksum</code> and <code>RawSentence</code> must not be used.
+ /// If <code>true</code>, the sentence may still contain invalid values.
+ /// </summary>
+ public bool IsSentenceValid { get; }
+
+ /// <summary>
+ /// The talker of the NMEA sentence.
+ /// </summary>
+ public string Talker { get; }
+
+ /// <summary>
+ /// The NMEA message type.
+ /// </summary>
+ public string MessageType { get; }
+
+ /// <summary>
+ /// The data fields of the NMEA message.
+ /// </summary>
+ public List<string> Data { get; }
+
+ /// <summary>
+ /// The checksum of the message, if present.
+ /// If the message did not contain a checksum, <code>Checksum</code> equals -1.
+ /// </summary>
+ public int Checksum { get; }
+
+ /// <summary>
+ /// The raw, unparsed NMEA sentence.
+ /// </summary>
+ public string RawSentence { get; }
+
+ public NMEASentence(bool isSentenceValid, string talker, string messageType, List<string> data, int checksum, string rawSentence) {
+ IsSentenceValid = isSentenceValid;
+
+ Talker = talker;
+ MessageType = messageType;
+ Data = data;
+ Checksum = checksum;
+
+ RawSentence = rawSentence;
+ }
+ }
+
+ class NMEASerialPort {
+ private StringBuilder sentenceBuffer;
+ private bool inSentence;
+
+ private SerialPort serialPort;
+
+ private bool running;
+ private Thread readThread;
+
+ /// <summary>
+ /// A delegate which is used for the <code>SentenceReceived</code> event.
+ /// </summary>
+ /// <param name="sentence">The parsed NMEA sentence which was received.</param>
+ public delegate void SentenceReceivedEventHandler(NMEASentence sentence);
+
+ /// <summary>
+ /// An event which is called when a sentence is received over the serial port.
+ /// </summary>
+ public event SentenceReceivedEventHandler SentenceReceived;
+
+ /// <summary>
+ /// Creates an instance of the NMEASerialPort class, which processes serial data from an NMEA device.
+ /// The serial port passed into the function must not be opened.
+ /// </summary>
+ /// <param name="serialPort">The serial port with which to communicate with the NMEA device.</param>
+ public NMEASerialPort(SerialPort serialPort) {
+ sentenceBuffer = new StringBuilder();
+ inSentence = false;
+
+ this.serialPort = serialPort;
+
+ readThread = new Thread(ReadSerialPort);
+ readThread.Name = "NMEASerialPort Read";
+ }
+
+ /// <summary>
+ /// Begins processing serial data and firing SentenceReceived events.
+ /// </summary>
+ public void Open() {
+ running = true;
+
+ serialPort.Open();
+ readThread.Start();
+ }
+
+ /// <summary>
+ /// Stops processing serial data and firing SentenceReceived events.
+ /// </summary>
+ public void Close() {
+ running = false;
+
+ readThread.Join();
+ serialPort.Close();
+ }
+
+ private void ProcessSentence() {
+ string sentence = sentenceBuffer.ToString();
+
+ List<string> components = new List<string>(sentence.Split(','));
+
+ string talkerAndMessageType = components[0];
+ string talker = talkerAndMessageType.Substring(0, 2);
+ string messageType = talkerAndMessageType.Substring(2);
+
+ List<string> data = components.GetRange(1, components.Count - 1);
+
+ string lastEntry = data[data.Count - 1];
+
+ int checksum = -1;
+
+ // Check if last entry is long enough to have a checksum at the end, and if so,
+ // if there's a star character there
+ if (lastEntry.Length >= 3 && lastEntry[lastEntry.Length - 3] == '*') {
+ // Fix last entry by removing checksum
+ data[data.Count - 1] = lastEntry.Substring(0, lastEntry.Length - 3);
+
+ string checksumString = lastEntry.Substring(lastEntry.Length - 2);
+ checksum = Convert.ToInt32(checksumString, 16);
+ }
+
+ SentenceReceived?.Invoke(new NMEASentence(true, talker, messageType, data, checksum, sentence));
+ }
+
+ private void ProcessByte(byte b) {
+ char c = (char) b;
+
+ if (inSentence) {
+ if (c != '\r') {
+ sentenceBuffer.Append(c);
+ } else {
+ ProcessSentence();
+
+ sentenceBuffer = new StringBuilder();
+ inSentence = false;
+ }
+ } else {
+ if (c == '$') {
+ inSentence = true;
+ }
+ }
+ }
+
+ private void ReadSerialPort() {
+ while (running) {
+ if (serialPort.BytesToRead > 0) {
+ int possibleCurrentByte = serialPort.ReadByte();
+
+ if (possibleCurrentByte != -1) {
+ ProcessByte((byte) possibleCurrentByte);
+ }
+ }
+ }
+ }
+ }
+}
diff --git a/GPSDOTimeSync/TimeProviders/NMEA/NMEATimeProvider.cs b/GPSDOTimeSync/TimeProviders/NMEA/NMEATimeProvider.cs
new file mode 100644
index 0000000..528be9c
--- /dev/null
+++ b/GPSDOTimeSync/TimeProviders/NMEA/NMEATimeProvider.cs
@@ -0,0 +1,50 @@
+using System;
+using System.Diagnostics;
+
+namespace GPSDOTimeSync.TimeProviders.NMEA {
+ class NMEATimeProvider : ITimeProvider {
+ private NMEASerialPort nmeaSerialPort;
+
+ public event TimeAvailableEventHandler TimeAvailable;
+ public event LogEventHandler Log;
+
+ /// <summary>
+ /// Creates an instance of the NMEATimeProvider class, which provides time information through the <code>ITimeProvider</code> interface.
+ /// The <code>NMEASerialPort</code> instance passed into this function must not be open.
+ /// </summary>
+ /// <param name="nmeaSerialPort">The <code>NMEASerialPort</code> instance to use when communicating with the NMEA device.</param>
+ public NMEATimeProvider(NMEASerialPort nmeaSerialPort) {
+ this.nmeaSerialPort = nmeaSerialPort;
+
+ nmeaSerialPort.SentenceReceived += SentenceReceived;
+ }
+
+ public void Start() {
+ nmeaSerialPort.Open();
+ }
+
+ public void Stop() {
+ nmeaSerialPort.Close();
+ }
+
+ private void SentenceReceived(NMEASentence sentence) {
+ if (sentence.IsSentenceValid) {
+ if (sentence.Talker == "GP" && sentence.MessageType == "RMC") {
+ string timeString = sentence.Data[0];
+ int hour = int.Parse(timeString.Substring(0, 2));
+ int minute = int.Parse(timeString.Substring(2, 2));
+ int second = int.Parse(timeString.Substring(4, 2));
+
+ string dateString = sentence.Data[8];
+ int day = int.Parse(dateString.Substring(0, 2));
+ int month = int.Parse(dateString.Substring(2, 2));
+ int year = 2000 + int.Parse(dateString.Substring(4, 2));
+
+ TimeAvailable?.Invoke(new DateTime(year, month, day, hour, minute, second));
+ }
+ } else {
+ Log?.Invoke("An invalid packet was received.", LogLevel.Warning);
+ }
+ }
+ }
+}