Started working on getting the basic communications with the scope working.

Working on routines to get and set the date and time in the handbox.

MeadeAutostar497/Controller/TelescopeController.cs

@@ -1,4 +1,8 @@
 using System;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading;
 using ASCOM.Utilities;
 using ASCOM.Utilities.Interfaces;
 
@@ -10,6 +14,8 @@ namespace ASCOM.MeadeAutostar497.Controller
 
         public static TelescopeController Instance => lazy.Value;
 
+        private Mutex serialMutex = new Mutex();
+
         private ISerial _serialPort;
         public ISerial SerialPort
         {
@@ -22,7 +28,7 @@ namespace ASCOM.MeadeAutostar497.Controller
                 if (_serialPort != null)
                 {
                     if (_serialPort.Connected)
-                        throw new InvalidOperationException("Please disconnect before changing the port.");
+                        throw new InvalidOperationException("Please disconnect before changing the serial engine.");
                 }
 
                 _serialPort = value;
@@ -40,10 +46,18 @@ namespace ASCOM.MeadeAutostar497.Controller
                 if (Connected)
                     throw new InvalidOperationException("Please disconnect from the scope before changing port.");
 
+                if (!ValidPort(value))
+                    throw new InvalidOperationException($"Unable to select port {value} as it does not exist.");
+
                 _port = value;
             }
         }
 
+        private bool ValidPort(string value)
+        {
+            return SerialPort.AvailableComPorts.Contains(value);
+        }
+
         public bool Connected
         {
             get => SerialPort.Connected;
@@ -55,16 +69,24 @@ namespace ASCOM.MeadeAutostar497.Controller
                 if (value)
                 {
                     //Connecting
-                    SerialPort.DTREnable = false;
-                    SerialPort.RTSEnable = false;
-                    SerialPort.Speed = SerialSpeed.ps9600;
-                    SerialPort.DataBits = 8;
-                    SerialPort.StopBits = SerialStopBits.One;
-                    SerialPort.Parity = SerialParity.None;
-                    SerialPort.PortName = Port;
-                    SerialPort.Connected = true;
+                    try
+                    {
+                        SerialPort.DTREnable = false;
+                        SerialPort.RTSEnable = false;
+                        SerialPort.Speed = SerialSpeed.ps9600;
+                        SerialPort.DataBits = 8;
+                        SerialPort.StopBits = SerialStopBits.One;
+                        SerialPort.Parity = SerialParity.None;
+                        SerialPort.PortName = Port;
+                        SerialPort.Connected = true;
 
-                    //todo perform test to ensure that connection has been made correctly.
+                        TestConnectionActive();
+                    }
+                    catch (Exception)
+                    {
+                        SerialPort.Connected = false;
+                        throw;
+                    }
                 }
                 else
                 {
@@ -74,13 +96,100 @@ namespace ASCOM.MeadeAutostar497.Controller
             }
         }
 
+        private void TestConnectionActive()
+        {
+            var firmwareVersionNumber = CommandString("GVN");
+            if (string.IsNullOrEmpty(firmwareVersionNumber))
+            {
+                throw new InvalidOperationException("Failed to communicate with telescope."); 
+            }
+        }
+
+        public string CommandString(string command)
+        {
+            return CommandString($"#:{command}#", false);
+        }
+
         public string CommandString(string command, bool raw)
         {
             // it's a good idea to put all the low level communication with the device here,
             // then all communication calls this function
             // you need something to ensure that only one command is in progress at a time
+            return SerialCommand(command, true);
+        }
 
-            throw new ASCOM.MethodNotImplementedException("CommandString");
+        public bool Slewing
+        {
+            get
+            {
+                if (!Connected) return false;
+
+                var result = CommandString("D");
+                return result != string.Empty;
+            }
+        }
+
+        public DateTime utcDate
+        {
+            get
+            {
+                string telescopeDate = CommandString("GC");
+                string telescopeTime = CommandString("GL");
+
+                int month = telescopeDate.Substring(0, 2).ToInteger();
+                int day = telescopeDate.Substring(3, 2).ToInteger();
+                int year = telescopeDate.Substring(6, 2).ToInteger();
+
+                if (year < 2000) //This is a hack that will work until the end of the century
+                {
+                    year = year + 2000;
+                }
+
+                int hour = telescopeTime.Substring(0, 2).ToInteger();
+                int minute = telescopeTime.Substring(3, 2).ToInteger();
+                int second = telescopeTime.Substring(6, 2).ToInteger();
+
+                var newDate = new DateTime(year, month, day, hour, minute, second, DateTimeKind.Utc);
+
+                return newDate;
+            }
+            set
+            {
+                //var result = SerialCommand(":SLHH:MM:SS#", true);
+                var timeResult = SerialCommand($"#:SL{value:hh:mm:ss}#", true);
+                if (timeResult != "1")
+                {
+                    throw new InvalidOperationException("Failed to set local time");
+                }
+
+                var dateResult = SerialCommand($"#:SC{value:MM/dd/yy}#", true);
+                if (dateResult.Substring(0,1) != "1")
+                {
+                    throw new InvalidOperationException("Failed to set local time");
+                }
+            }
+
+        }
+
+        private string SerialCommand(string command, bool expectsResult )
+        {
+            serialMutex.WaitOne();
+            try
+            {
+                SerialPort.Transmit(command);
+                if (expectsResult)
+                {
+                    string result = SerialPort.ReceiveTerminated("#");
+
+                    return result;
+                }               
+                return string.Empty;
+            }
+            finally
+            {
+                SerialPort.ClearBuffers();
+                serialMutex.ReleaseMutex();
+            }
         }
     }
 }