Added DTC support

(this will most likely only work for up to 3 trouble codes)

OBD.NET/OBD.NET.Common/Devices/CommandResult.cs

@@ -7,6 +7,7 @@ namespace OBD.NET.Common.Devices
         #region Properties & Fields
 
         public object Result { get; set; }
+        public string RawResult { get; set; }
         public AsyncManualResetEvent WaitHandle { get; }
 
         #endregion

OBD.NET/OBD.NET.Common/Devices/ELM327.cs

@@ -11,6 +11,7 @@ using OBD.NET.Common.Events.EventArgs;
 using OBD.NET.Common.Extensions;
 using OBD.NET.Common.Logging;
 using OBD.NET.Common.OBDData;
+using OBD.NET.Common.OBDData.DTC;
 
 namespace OBD.NET.Common.Devices
 {
@@ -147,33 +148,63 @@ namespace OBD.NET.Common.Devices
             return result.Result;
         }
 
+        public virtual TroubleCode[] RequestDTCs() => RequestDTCsAsync().Result;
+
+        public virtual async Task<TroubleCode[]> RequestDTCsAsync()
+        {
+            Logger?.WriteLine("Requesting DTCs ...", OBDLogLevel.Debug);
+            MonitorStatusSinceDTCsClreared dtcStatus = await RequestDataAsync<MonitorStatusSinceDTCsClreared>();
+
+            CommandResult result = SendCommand(((int)Mode.ShowStoredDiagnosticTroubleCodes).ToString());
+            await result.WaitHandle.WaitAsync();
+
+            if (!(result.Result is List<TroubleCode> resultCodes)) return new TroubleCode[0];
+
+            int count = Math.Min(dtcStatus.DTCCount, resultCodes.Count);
+            return resultCodes.Take(count).ToArray();
+        }
+
         protected override object ProcessMessage(string message)
         {
             DateTime timestamp = DateTime.Now;
 
             RawDataReceived?.Invoke(this, new RawDataReceivedEventArgs(message, timestamp));
 
-            if (message.Length > 4)
+            if (message.Length >= 4)
             {
                 if (message[0] == '4')
                 {
                     byte mode = (byte)message[1].GetHexVal();
-                    if (mode == (byte)Mode)
+                    switch ((Mode)mode)
                     {
-                        byte pid = (byte)message.Substring(2, 2).GetHexVal();
-                        if (DataTypeCache.TryGetValue(pid, out Type dataType))
-                        {
-                            IOBDData obdData = (IOBDData)Activator.CreateInstance(dataType);
-                            obdData.Load(message.Substring(4, message.Length - 4));
+                        case Mode.ShowCurrentData:
+                            byte pid = (byte)message.Substring(2, 2).GetHexVal();
+                            if (DataTypeCache.TryGetValue(pid, out Type dataType))
+                            {
+                                IOBDData obdData = (IOBDData)Activator.CreateInstance(dataType);
+                                obdData.Load(message.Substring(4));
 
-                            if (DataReceivedEventHandlers.TryGetValue(dataType, out IDataEventManager dataEventManager))
-                                dataEventManager.RaiseEvent(this, obdData, timestamp);
+                                if (DataReceivedEventHandlers.TryGetValue(dataType, out IDataEventManager dataEventManager))
+                                    dataEventManager.RaiseEvent(this, obdData, timestamp);
 
-                            if (DataReceivedEventHandlers.TryGetValue(typeof(IOBDData), out IDataEventManager genericDataEventManager))
-                                genericDataEventManager.RaiseEvent(this, obdData, timestamp);
+                                if (DataReceivedEventHandlers.TryGetValue(typeof(IOBDData), out IDataEventManager genericDataEventManager))
+                                    genericDataEventManager.RaiseEvent(this, obdData, timestamp);
 
-                            return obdData;
-                        }
+                                return obdData;
+                            }
+                            break;
+
+                        case Mode.ShowStoredDiagnosticTroubleCodes:
+                            //TODO DarthAffe 14.09.2017: I think multiple frames (as stated in the documentation for dtcs) aren't supported right now - how to handle them?
+                            List<TroubleCode> troubleCodes = new List<TroubleCode>();
+                            for (int i = 2; (i + 3) < message.Length; i += 4)
+                            {
+                                string dtc = message.Substring(i, 4);
+                                TroubleCode troubleCode = new TroubleCode();
+                                troubleCode.Load(dtc);
+                                troubleCodes.Add(troubleCode);
+                            }
+                            return troubleCodes;
                     }
                 }
             }

OBD.NET/OBD.NET.Common/Devices/SerialDevice.cs

@@ -183,6 +183,7 @@ namespace OBD.NET.Common.Devices
         {
             object data = ProcessMessage(message);
             CurrentCommand.CommandResult.Result = data;
+            CurrentCommand.CommandResult.RawResult = message;
         }
 
         /// <summary>

OBD.NET/OBD.NET.Common/OBDData/00-1F/MonitorStatusSinceDTCsClreared.cs

@@ -0,0 +1,29 @@
+namespace OBD.NET.Common.OBDData
+{
+    public class MonitorStatusSinceDTCsClreared : AbstractOBDData
+    {
+        #region Properties & Fields
+
+        public bool IsMilOn => (A & (1 << 7)) != 0;
+
+        public int DTCCount => A & ~(1 << 7);
+
+        //TODO DarthAffe 26.08.2017: Implement Test-Bits https://en.wikipedia.org/wiki/OBD-II_PIDs#Mode_1_PID_01
+
+        #endregion
+
+        #region Constructors
+
+        public MonitorStatusSinceDTCsClreared()
+            : base(0x01, 4)
+        { }
+
+        #endregion
+
+        #region Methods
+
+        public override string ToString() => IsMilOn.ToString();
+
+        #endregion
+    }
+}

OBD.NET/OBD.NET.Common/OBDData/DTC/TroubleCode.cs

@@ -0,0 +1,122 @@
+using System;
+using System.Collections.Generic;
+using OBD.NET.Common.Extensions;
+
+namespace OBD.NET.Common.OBDData.DTC
+{
+    public class TroubleCode : AbstractOBDData
+    {
+        #region Properties & Fields
+
+        private static readonly Dictionary<TroublePart, string> PART_DESCRIPTION = new Dictionary<TroublePart, string>
+        {
+
+            { TroublePart.Powertrain, "P" },
+            { TroublePart.Chassis, "C" },
+            { TroublePart.Body, "B" },
+            { TroublePart.Network, "U" },
+        };
+
+        public TroublePart TroublePart
+        {
+            get
+            {
+                byte data = (byte)(A & 0b11000000);
+                switch (data)
+                {
+                    case 0:
+                        return TroublePart.Powertrain;
+                    case 0b01000000:
+                        return TroublePart.Chassis;
+                    case 0b10000000:
+                        return TroublePart.Body;
+                    case 0b11000000:
+                        return TroublePart.Network;
+                    default:
+                        throw new IndexOutOfRangeException($"Can't parse TroublePart with data {data}");
+                }
+            }
+        }
+
+        public Definition Definition
+        {
+            get
+            {
+                byte data = (byte)(A & 0b00110000);
+                switch (data)
+                {
+                    case 0:
+                        return Definition.SAEJ2012;
+                    case 0b01000000:
+                        return Definition.Custom;
+                    case 0b10000000:
+                        return Definition.Undefined;
+                    case 0b11000000:
+                        return Definition.Undefined2;
+                    default:
+                        throw new IndexOutOfRangeException($"Can't parse Definition with data {data}");
+                }
+            }
+        }
+
+        public SpecificPart SpecificPart => (SpecificPart)(A & 0b00001111);
+
+        public string FaultCode => B.ToHexString();
+
+        #endregion
+
+        #region Constructors
+
+        public TroubleCode()
+            : base(byte.MaxValue, 2) // DarthAffe 14.09.2017: Trouble-Codes don't have a pid
+        { }
+
+        #endregion
+
+        #region Methods
+
+        public override string ToString() => $"{PART_DESCRIPTION[TroublePart]}{(int)Definition}{((byte)SpecificPart).ToHexString()[1]}{FaultCode}";
+
+        #endregion
+    }
+
+    #region Data
+
+    public enum TroublePart
+    {
+        Powertrain = 0,
+        Chassis = 1,
+        Body = 2,
+        Network = 3
+    }
+
+    public enum Definition
+    {
+        SAEJ2012 = 0,
+        Custom = 1,
+        Undefined = 2,
+        Undefined2 = 3
+    }
+
+    public enum SpecificPart
+    {
+        Undefined = 0,
+        FuelAndAirMetering = 1,
+        FuelAndAirMeteringInjectorCircuit = 2,
+        IgnitionSystemOfMisfire = 3,
+        AuxiliaryEmissionControls = 4,
+        VehicleSpeedControlAndIdleControlSystem = 5,
+        ComputerOutputCircuit = 6,
+        Transmission = 7,
+        Transmission2 = 8,
+        Undefined2 = 9,
+        Undefined3 = 10,
+        Undefined4 = 11,
+        Undefined5 = 12,
+        Undefined6 = 13,
+        Undefined7 = 14,
+        Undefined8 = 15,
+    }
+
+    #endregion
+}