/// <summary>
/// Closes the serial port.
/// </summary>
private void CloseSerialPort()
{
lock (_lock)
{
Trace.TraceInformation("{0}.CloseSerialPort: CommPort={1}", CLASSNAME, _serialPort.PortName);
// Attempt to close the serial port object
if (_serialPort != null)
{
_serialPort.DataReceived -= SerialPort_DataReceived;
_serialPort.ErrorReceived -= SerialPort_ErrorReceived;
if (_serialPort.IsOpen)
{
try
{
_serialPort.Close();
}
catch (IOException) { }
catch (Exception ex)
{
Trace.TraceError("{0}.CloseSerialPort: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
throw ex;
}
}
_serialPort.Dispose();
_serialPort = null;
_buffer = null;
_bufPos = 0;
_state = RecvrState.NoDeviceFound;
}
} // end lock
}
/// <summary>
/// Opens the serial port.
/// </summary>
private void OpenSerialPort(string commPort)
{
lock (_lock)
{
// Open the serial port connection
_serialPort = new SerialPort()
{
PortName = commPort,
BaudRate = BAUD_RATE,
DataBits = DATA_BITS,
StopBits = STOP_BITS,
Parity = PARITY,
WriteTimeout = WRITE_TIMEOUT,
Handshake = HANDSHAKE
};
Trace.TraceInformation("{0}.OpenSerialPort: CommPort={1}", CLASSNAME, _serialPort.PortName);
try
{
_serialPort.Open();
}
catch (Exception ex)
{
Trace.TraceError("{0}.OpenSerialPort: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
throw ex;
}
_buffer = new byte[BUFFER_SIZE];
_bufPos = 0;
_state = RecvrState.Waiting;
_serialPort.DataReceived += SerialPort_DataReceived;
_serialPort.ErrorReceived += SerialPort_ErrorReceived;
GC.SuppressFinalize(_serialPort.BaseStream); // Work around, see http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/8a1825d2-c84b-4620-91e7-3934a4d47330
} // end lock
}
/// <summary>
/// Handles the DataReceived event of the serialPort control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.IO.Ports.SerialDataReceivedEventArgs"/> instance containing the event data.</param>
private void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
// Data format: STX COUNT DATA ... CHECKSUM ETX
DataPacketReceivedEventArgs eventData = null;
lock (_lock)
{
try
{
while (_serialPort.BytesToRead > 0)
{
byte data = (byte)_serialPort.ReadByte();
switch (_state)
{
case RecvrState.Waiting:
if (data == 0x02)
{
_state = RecvrState.PacketLength;
}
break;
case RecvrState.PacketLength:
_checksum = data;
_dataLength = data - 1;
_bufPos = 0;
_buffer.Initialize();
_state = RecvrState.PacketData;
break;
case RecvrState.PacketData:
if (_bufPos < _dataLength)
{
_buffer[_bufPos++] = data;
_checksum ^= data;
}
if (_bufPos == _dataLength)
{
_state = RecvrState.Checksum;
}
break;
case RecvrState.Checksum:
if (_checksum != data)
{
Trace.TraceWarning("{0}.SerialPort_DataReceived: Checksum mismatch. Expected={1} Actual={2}", CLASSNAME, _checksum, data);
_state = RecvrState.Waiting;
}
else
{
_state = RecvrState.Received;
}
break;
case RecvrState.Received:
if (data == 0x03)
{
// We got a message!
eventData = new DataPacketReceivedEventArgs()
{
CommPort = _serialPort.PortName,
DataLength = _dataLength,
DataPacket = new byte[_bufPos]
};
Array.Copy(_buffer, 0, eventData.DataPacket, 0, _bufPos);
_state = RecvrState.Waiting;
}
break;
default:
Trace.TraceError("{0}.SerialPort_DataReceived: Unknown receive state, resetting state");
_state = RecvrState.Waiting;
break;
}
}
}
catch (InvalidOperationException ex)
{
Trace.TraceError("{0}.SerialPort_DataReceived: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
}
} // end lock
// Fire event if we have data (we are outside our lock here)
if (eventData != null)
{
OnDataPacketReceived(eventData);
}
}
/// <summary>
/// Handles the ErrorReceived event of the serialPort control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.IO.Ports.SerialErrorReceivedEventArgs"/> instance containing the event data.</param>
private void SerialPort_ErrorReceived(object sender, SerialErrorReceivedEventArgs e)
{
_state = RecvrState.Waiting;
}
/// <summary>
/// Handles the DataReceived event of the serialPort control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.IO.Ports.SerialDataReceivedEventArgs"/> instance containing the event data.</param>
private void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
// Data format: STX COUNT DATA ... CHECKSUM ETX
DataPacketReceivedEventArgs eventData = null;
lock (_lock)
{
try
{
while (_serialPort.BytesToRead > 0)
{
byte data = (byte)_serialPort.ReadByte();
switch (_state)
{
case RecvrState.Waiting:
if (data == 0x02)
{
_state = RecvrState.PacketLength;
}
break;
case RecvrState.PacketLength:
_checksum = data;
_dataLength = data - 1;
_bufPos = 0;
_buffer.Initialize();
_state = RecvrState.PacketData;
break;
case RecvrState.PacketData:
if (_bufPos < _dataLength)
{
_buffer[_bufPos++] = data;
_checksum ^= data;
}
if (_bufPos == _dataLength)
{
_state = RecvrState.Checksum;
}
break;
case RecvrState.Checksum:
if (_checksum != data)
{
Trace.TraceWarning("{0}.SerialPort_DataReceived: Checksum mismatch. Expected={1} Actual={2}", CLASSNAME, _checksum, data);
_state = RecvrState.Waiting;
}
else
{
_state = RecvrState.Received;
}
break;
case RecvrState.Received:
if (data == 0x03)
{
// We got a message!
eventData = new DataPacketReceivedEventArgs()
{
CommPort = _serialPort.PortName,
DataLength = _dataLength,
DataPacket = new byte[_bufPos]
};
Array.Copy(_buffer, 0, eventData.DataPacket, 0, _bufPos);
_state = RecvrState.Waiting;
}
break;
default:
Trace.TraceError("{0}.SerialPort_DataReceived: Unknown receive state, resetting state");
_state = RecvrState.Waiting;
break;
}
}
}
catch (InvalidOperationException ex)
{
Trace.TraceError("{0}.SerialPort_DataReceived: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
}
} // end lock
// Fire event if we have data (we are outside our lock here)
if (eventData != null) OnDataPacketReceived(eventData);
}
/// <summary>
/// Handles the ErrorReceived event of the serialPort control.
/// </summary>
/// <param name="sender">The source of the event.</param>
/// <param name="e">The <see cref="System.IO.Ports.SerialErrorReceivedEventArgs"/> instance containing the event data.</param>
private void SerialPort_ErrorReceived(object sender, SerialErrorReceivedEventArgs e)
{
_state = RecvrState.Waiting;
}
/// <summary>
/// Closes the serial port.
/// </summary>
private void CloseSerialPort()
{
lock (_lock)
{
Trace.TraceInformation("{0}.CloseSerialPort: CommPort={1}", CLASSNAME, _serialPort.PortName);
// Attempt to close the serial port object
if (_serialPort != null)
{
_serialPort.DataReceived -= SerialPort_DataReceived;
_serialPort.ErrorReceived -= SerialPort_ErrorReceived;
if (_serialPort.IsOpen)
{
try
{
_serialPort.Close();
}
catch (IOException) { }
catch (Exception ex)
{
Trace.TraceError("{0}.CloseSerialPort: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
throw ex;
}
}
_serialPort.Dispose();
_serialPort = null;
_buffer = null;
_bufPos = 0;
_state = RecvrState.NoDeviceFound;
}
} // end lock
}
/// <summary>
/// Opens the serial port.
/// </summary>
private void OpenSerialPort(string commPort)
{
lock (_lock)
{
// Open the serial port connection
_serialPort = new SerialPort()
{
PortName = commPort,
BaudRate = BAUD_RATE,
DataBits = DATA_BITS,
StopBits = STOP_BITS,
Parity = PARITY,
WriteTimeout = WRITE_TIMEOUT,
Handshake = HANDSHAKE
};
Trace.TraceInformation("{0}.OpenSerialPort: CommPort={1}", CLASSNAME, _serialPort.PortName);
try
{
_serialPort.Open();
}
catch (Exception ex)
{
Trace.TraceError("{0}.OpenSerialPort: CommPort={1} Exception={2}", CLASSNAME, _serialPort.PortName, ex.GetBaseException());
throw ex;
}
_buffer = new byte[BUFFER_SIZE];
_bufPos = 0;
_state = RecvrState.Waiting;
_serialPort.DataReceived += SerialPort_DataReceived;
_serialPort.ErrorReceived += SerialPort_ErrorReceived;
GC.SuppressFinalize(_serialPort.BaseStream); // Work around, see http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/8a1825d2-c84b-4620-91e7-3934a4d47330
} // end lock
}
