Now reading data in more "proper" way.

Changed default baud rate for quicker local testing. Default value shouldn't matter anyway.

src/OpenSerialPortMonitor/ViewModels/SerialConnectorViewModel.cs

@@ -1,123 +1,123 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using Caliburn.Micro;
-using Whitestone.OpenSerialPortMonitor.SerialCommunication;
-using Whitestone.OpenSerialPortMonitor.Main.Messages;
-using System.IO.Ports;
-using System.Windows;
-
-namespace Whitestone.OpenSerialPortMonitor.Main.ViewModels
-{
-    public class SerialConnectorViewModel : PropertyChangedBase, IHandle<ConnectionError>
-    {
-        private readonly IEventAggregator _eventAggregator;
-
-        public BindableCollection<string> ComPorts { get; set; }
-        public BindableCollection<int> BaudRates { get; set; }
-        public BindableCollection<Parity> Parities { get; set; }
-        public BindableCollection<int> DataBits { get; set; }
-        public BindableCollection<StopBits> StopBits { get; set; }
-
-        public string SelectedComPort { get; set; }
-        public int SelectedBaudRate { get; set; }
-        public int SelectedDataBits { get; set; }
-        public Parity SelectedParity { get; set; }
-        public StopBits SelectedStopBits { get; set; }
-
-        private bool _isConnected = false;
-        public bool IsConnected
-        {
-            get { return _isConnected; }
-            set
-            {
-                _isConnected = value;
-                NotifyOfPropertyChange(() => IsConnected);
-                NotifyOfPropertyChange(() => IsDisconnected);
-            }
-        }
-        public bool IsDisconnected
-        {
-            get { return !_isConnected; }
-            set
-            {
-                _isConnected = !value;
-                NotifyOfPropertyChange(() => IsConnected);
-                NotifyOfPropertyChange(() => IsDisconnected);
-            }
-        }
-
-        public SerialConnectorViewModel(IEventAggregator eventAggregator)
-        {
-            _eventAggregator = eventAggregator;
-            _eventAggregator.Subscribe(this);
-
-            BindValues();
-        }
-
-        private void BindValues()
-        {
-            BaudRates = new BindableCollection<int>() { 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 };
-            SelectedBaudRate = 4800;
-
-            DataBits = new BindableCollection<int>() { 5, 6, 7, 8, 9 };
-            SelectedDataBits = 8;
-
-            Parities = new BindableCollection<Parity>();
-            foreach (Parity p in Enum.GetValues(typeof(Parity)))
-            {
-                Parities.Add(p);
-            }
-            SelectedParity = Parity.None;
-
-            StopBits = new BindableCollection<StopBits>();
-            foreach (StopBits s in Enum.GetValues(typeof(StopBits)))
-            {
-                StopBits.Add(s);
-            }
-            SelectedStopBits = System.IO.Ports.StopBits.One;
-
-
-            IEnumerable<string> ports = SerialReader.GetAvailablePorts();
-            ComPorts = new BindableCollection<string>();
-            ComPorts.AddRange(ports);
-
-            SelectedComPort = ports.FirstOrDefault();
-        }
-
-        public void Connect()
-        {
-            IsConnected = true;
-
-            _eventAggregator.PublishOnUIThread(new SerialPortConnect
-            {
-                PortName = SelectedComPort,
-                BaudRate = SelectedBaudRate,
-                DataBits = SelectedDataBits,
-                Parity = SelectedParity,
-                StopBits = SelectedStopBits
-            });
-        }
-
-        public void Disconnect()
-        {
-            IsConnected = false;
-
-            _eventAggregator.PublishOnUIThread(new SerialPortDisconnect());
-        }
-
-        public void Handle(ConnectionError message)
-        {
-            IsConnected = false;
-
-            string errorMessage = message.Exception.Message;
-            if (message.Exception.InnerException != null)
-            {
-                errorMessage = message.Exception.InnerException.Message;
-            }
-            MessageBox.Show(errorMessage, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
-        }
-    }
-}
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Caliburn.Micro;
+using Whitestone.OpenSerialPortMonitor.SerialCommunication;
+using Whitestone.OpenSerialPortMonitor.Main.Messages;
+using System.IO.Ports;
+using System.Windows;
+
+namespace Whitestone.OpenSerialPortMonitor.Main.ViewModels
+{
+    public class SerialConnectorViewModel : PropertyChangedBase, IHandle<ConnectionError>
+    {
+        private readonly IEventAggregator _eventAggregator;
+
+        public BindableCollection<string> ComPorts { get; set; }
+        public BindableCollection<int> BaudRates { get; set; }
+        public BindableCollection<Parity> Parities { get; set; }
+        public BindableCollection<int> DataBits { get; set; }
+        public BindableCollection<StopBits> StopBits { get; set; }
+
+        public string SelectedComPort { get; set; }
+        public int SelectedBaudRate { get; set; }
+        public int SelectedDataBits { get; set; }
+        public Parity SelectedParity { get; set; }
+        public StopBits SelectedStopBits { get; set; }
+
+        private bool _isConnected = false;
+        public bool IsConnected
+        {
+            get { return _isConnected; }
+            set
+            {
+                _isConnected = value;
+                NotifyOfPropertyChange(() => IsConnected);
+                NotifyOfPropertyChange(() => IsDisconnected);
+            }
+        }
+        public bool IsDisconnected
+        {
+            get { return !_isConnected; }
+            set
+            {
+                _isConnected = !value;
+                NotifyOfPropertyChange(() => IsConnected);
+                NotifyOfPropertyChange(() => IsDisconnected);
+            }
+        }
+
+        public SerialConnectorViewModel(IEventAggregator eventAggregator)
+        {
+            _eventAggregator = eventAggregator;
+            _eventAggregator.Subscribe(this);
+
+            BindValues();
+        }
+
+        private void BindValues()
+        {
+            BaudRates = new BindableCollection<int>() { 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 };
+            SelectedBaudRate = 115200;
+
+            DataBits = new BindableCollection<int>() { 5, 6, 7, 8, 9 };
+            SelectedDataBits = 8;
+
+            Parities = new BindableCollection<Parity>();
+            foreach (Parity p in Enum.GetValues(typeof(Parity)))
+            {
+                Parities.Add(p);
+            }
+            SelectedParity = Parity.None;
+
+            StopBits = new BindableCollection<StopBits>();
+            foreach (StopBits s in Enum.GetValues(typeof(StopBits)))
+            {
+                StopBits.Add(s);
+            }
+            SelectedStopBits = System.IO.Ports.StopBits.One;
+
+
+            IEnumerable<string> ports = SerialReader.GetAvailablePorts();
+            ComPorts = new BindableCollection<string>();
+            ComPorts.AddRange(ports);
+
+            SelectedComPort = ports.FirstOrDefault();
+        }
+
+        public void Connect()
+        {
+            IsConnected = true;
+
+            _eventAggregator.PublishOnUIThread(new SerialPortConnect
+            {
+                PortName = SelectedComPort,
+                BaudRate = SelectedBaudRate,
+                DataBits = SelectedDataBits,
+                Parity = SelectedParity,
+                StopBits = SelectedStopBits
+            });
+        }
+
+        public void Disconnect()
+        {
+            IsConnected = false;
+
+            _eventAggregator.PublishOnUIThread(new SerialPortDisconnect());
+        }
+
+        public void Handle(ConnectionError message)
+        {
+            IsConnected = false;
+
+            string errorMessage = message.Exception.Message;
+            if (message.Exception.InnerException != null)
+            {
+                errorMessage = message.Exception.InnerException.Message;
+            }
+            MessageBox.Show(errorMessage, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+        }
+    }
+}

src/SerialCommunication/SerialReader.cs

@@ -1,9 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.IO.Ports;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Timers;
 
 namespace Whitestone.OpenSerialPortMonitor.SerialCommunication
@@ -23,6 +22,8 @@ public class SerialReader : IDisposable
         private Timer _bufferTimer = null;
         private DateTime _lastReceivedData = DateTime.Now;
         private bool _disposed = false;
+        private System.Threading.Thread _readThread = null;
+        private bool _readThreadRunning = false;
 
         public SerialReader()
         {
@@ -68,7 +69,28 @@ public void Start(string portName, int baudRate, Parity parity, int dataBits, St
             }
 
             _serialPort.ReadTimeout = 100; // Milliseconds
-            _serialPort.DataReceived += SerialPortDataReceived;
+
+            _readThread = new System.Threading.Thread(ReadThread);
+            _readThreadRunning = true;
+            _readThread.Start();
+        }
+
+        private async void ReadThread()
+        {
+            while (_readThreadRunning)
+            {
+                // This is the proper way to read data, according to http://www.sparxeng.com/blog/software/must-use-net-system-io-ports-serialport
+                // Though he uses BeginRead/EndRead, ReadAsync is the preferred way in .NET 4.5
+                byte[] buffer = new byte[MAX_RECEIVE_BUFFER * 3];
+                int bytesRead = await _serialPort.BaseStream.ReadAsync(buffer, 0, buffer.Length);
+
+                byte[] received = new byte[bytesRead];
+                Buffer.BlockCopy(buffer, 0, received, 0, bytesRead);
+                lock (_receiveBuffer)
+                {
+                    _receiveBuffer.AddRange(received);
+                }
+            }
         }
 
         public void Send(byte[] data)
@@ -81,10 +103,11 @@ public void Send(byte[] data)
 
         public void Stop()
         {
+            _readThreadRunning = false;
+
             // Disconnect from the serial port
             if (_serialPort != null)
             {
-                _serialPort.DataReceived -= SerialPortDataReceived;
                 _serialPort.Close();
                 _serialPort.Dispose();
                 _serialPort = null;
@@ -104,35 +127,13 @@ public void Stop()
             }
         }
 
-        private void SerialPortDataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
-        {
-            // Read the data from COM and empty the COM buffer
-            SerialPort serialPort = (SerialPort)sender;
-            byte[] buffer = new byte[serialPort.BytesToRead];
-            serialPort.Read(buffer, 0, buffer.Length);
-
-            serialPort.DiscardInBuffer();
-
-            lock (_receiveBuffer)
-            {
-                _lastReceivedData = DateTime.Now;
-
-                _receiveBuffer.AddRange(buffer);
-
-                if (_receiveBuffer.Count >= MAX_RECEIVE_BUFFER)
-                {
-                    SendBuffer(ref _receiveBuffer);
-                }
-            }
-        }
-
         private void _bufferTimer_Elapsed(object sender, ElapsedEventArgs e)
         {
             lock (_receiveBuffer)
             {
                 // Only send data if the last data received was more than BUFFER_TIMER_INTERVAL milliseconds ago
                 // This is to ensure it only empties the buffer when not a lot of data has been received lately
-                if ((DateTime.Now - _lastReceivedData).TotalMilliseconds > BUFFER_TIMER_INTERVAL)
+                if ((DateTime.Now - _lastReceivedData).TotalMilliseconds > BUFFER_TIMER_INTERVAL && _receiveBuffer.Count > 0)
                 {
                     SendBuffer(ref _receiveBuffer);
                 }
@@ -144,15 +145,10 @@ private void SendBuffer(ref List<byte> buffer)
             byte[] byteBuffer = buffer.ToArray();
             buffer.Clear();
 
-            OnDataReceived(this, new SerialDataReceivedEventArgs() { Data = byteBuffer });
-        }
-
-        private void OnDataReceived(object sender, SerialDataReceivedEventArgs e)
-        {
             EventHandler<SerialDataReceivedEventArgs> handler = SerialDataReceived;
             if (handler != null)
             {
-                handler(this, e);
+                handler(this, new SerialDataReceivedEventArgs() { Data = byteBuffer });
             }
         }