For .net 1.1 I used OpenNETCF.IO.Serial because serial support was added to .net in version 2.0. It is for the compact framework but I used it for both compact devices and regular windows apps. You get the source code so you can modify it yourself which is what I did.
It basically creates a c# wrapper around the serial function imported out of kernel32.dll.
You might also want to have a look at How to capture a serial port that disappears because the usb cable gets unplugged
Here is the code that I used to call it
using OpenNETCF.IO.Serial;
public static Port port;
private DetailedPortSettings portSettings;
private Mutex UpdateBusy = new Mutex();
// create the port
try
{
// create the port settings
portSettings = new HandshakeNone();
portSettings.BasicSettings.BaudRate=BaudRates.CBR_9600;
// create a default port on COM3 with no handshaking
port = new Port("COM3:", portSettings);
// define an event handler
port.DataReceived +=new Port.CommEvent(port_DataReceived);
port.RThreshold = 1;
port.InputLen = 0;
port.SThreshold = 1;
try
{
port.Open();
}
catch
{
port.Close();
}
}
catch
{
port.Close();
}
private void port_DataReceived()
{
// since RThreshold = 1, we get an event for every character
byte[] inputData = port.Input;
// do something with the data
// note that this is called from a read thread so you should
// protect any data pass from here to the main thread using mutex
// don't forget the use the mutex in the main thread as well
UpdateBusy.WaitOne();
// copy data to another data structure
UpdateBusy.ReleaseMutex();
}
private void port_SendBuff()
{
byte[] outputData = new byte[esize];
crc=0xffff;
j=0;
outputData[j++]=FS;
// .. more code to fill up buff
outputData[j++]=FS;
// number of chars sent is determined by size of outputData
port.Output = outputData;
}
// code to close port
if (port.IsOpen)
{
port.Close();
}
port.Dispose();