public void Open(string portName, uint baudrate)
{
// Check if port can be found
bool isValid =
SerialPort.GetPortNames()
.Any(x => String.Compare(x, portName, StringComparison.OrdinalIgnoreCase) == 0);
if (!isValid)
{
throw new IOException(string.Format("{0} port was not found", portName));
}
string port = @"\\.\" + portName;
Handle = CreateFile(port, GenericRead | GenericWrite, 0, IntPtr.Zero, OpenExisting, 0, IntPtr.Zero);
if (Handle.IsInvalid)
{
throw new IOException(string.Format("{0} port is already open", portName));
}
var dcb = new Dcb();
// first get the current dcb structure setup
if (GetCommState(Handle, ref dcb) == false)
{
throw new IOException(string.Format("GetCommState error {0}", portName));
}
dcb.BaudRate = baudrate;
dcb.ByteSize = 8;
dcb.Flags = 129;
dcb.XoffChar = 0;
dcb.XonChar = 0;
/* Apply the settings */
if (SetCommState(Handle, ref dcb) == false)
{
throw new IOException(string.Format("SetCommState error {0}", portName));
}
/* Set DTR, some boards needs a DTR = 1 level */
if (EscapeCommFunction(Handle, Setdtr) == false)
{
throw new IOException(string.Format("EscapeCommFunction error {0}", portName));
}
// Write default timeouts
var cto = new Commtimeouts
{
ReadTotalTimeoutConstant = 500,
ReadTotalTimeoutMultiplier = 0,
ReadIntervalTimeout = 10,
WriteTotalTimeoutConstant = WriteTimeout,
WriteTotalTimeoutMultiplier = 0
};
if (SetCommTimeouts(Handle, ref cto) == false)
{
throw new IOException(string.Format("SetCommTimeouts error {0}", portName));
}
// Create filestream
_fileStream = new FileStream(Handle, FileAccess.ReadWrite, 32, false);
}
private bool ConfigureSerialPort()
{
var serialConfig = new DCB();
if (GetCommState(pHandle, ref serialConfig))
{
// setup the DCB struct with the serial settings we need
serialConfig.BaudRate = (uint)this.iBaudRate;
serialConfig.ByteSize = this.byteSize;
serialConfig.fBinary = 1; // must be true
serialConfig.fDtrControl = 1; // DTR_CONTROL_ENABLE "Enables the DTR line when the device is opened and leaves it on."
serialConfig.fAbortOnError = 0; // false
serialConfig.fTXContinueOnXoff = 0; // false
serialConfig.fParity = 1; // true so that the Parity member is looked at
switch (this.parity)
{
case SerialPortParity.Even:
serialConfig.Parity = 2;
break;
case SerialPortParity.Mark:
serialConfig.Parity = 3;
break;
case SerialPortParity.Odd:
serialConfig.Parity = 1;
break;
case SerialPortParity.Space:
serialConfig.Parity = 4;
break;
case SerialPortParity.None:
default:
serialConfig.Parity = 0;
break;
}
switch (this.stopBits)
{
case StopBits.One:
serialConfig.StopBits = 0;
break;
case StopBits.OnePointFive:
serialConfig.StopBits = 1;
break;
case StopBits.Two:
serialConfig.StopBits = 2;
break;
case StopBits.None:
default:
throw new ArgumentException("stopBits cannot be StopBits.None");
}
if (SetCommState(pHandle, ref serialConfig))
{
// set the serial connection timeouts
var timeouts = new Commtimeouts
{
ReadIntervalTimeout = 30,
ReadTotalTimeoutMultiplier = 0,
ReadTotalTimeoutConstant = 0,
WriteTotalTimeoutMultiplier = 0,
WriteTotalTimeoutConstant = 0
};
return SetCommTimeouts(this.pHandle, ref timeouts);
}
else
{
return false;
}
}
else
{
return false;
}
}
private static extern bool SetCommTimeouts(
SafeFileHandle hFile, // handle to comm device
ref Commtimeouts lpCommTimeouts // time-out values
);
protected static extern bool SetCommTimeouts(IntPtr hFile, ref Commtimeouts lpCommTimeouts);
