Hi,

I'm trying to send a sms via a Nokia phone over serial which is easy enough via putty. The commands from the nokia documentation works fine.

However, trying to send the same commands from a c# application fails miserably. I've run Sysinternals PortMon and can see the commands come through OK, the only difference I can see is in the way it connects but I am having trouble finding the commands that would iron out those differences.

The code I'm running looks a little bit like this

using (SerialPort port = new SerialPort(comPort, 9600, Parity.None, 8, StopBits.One))
    		{
    			port.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);
    			port.ErrorReceived += new SerialErrorReceivedEventHandler(port_ErrorReceived);

    			//port.ReceivedBytesThreshold = 1;
    			port.DtrEnable = true;
    			port.RtsEnable = true;
    			port.ReadTimeout = 1;
    			port.Handshake = Handshake.XOnXOff;


    			try
    			{
    				port.Open();

    				port.WriteLine("AT");

    				port.WriteLine("AT+CMGF=1");

    				port.WriteLine("AT+CMGS=\"" + number + "\"");

    				port.WriteLine(message);

    				port.Write(new byte[] { (byte)26 }, 0, 1);
    			}
    			finally
    			{
    				if (port.IsOpen)
    				{
    					port.Close();
    				}
    			}

The differences I'm seeing in the trace from the serial port are

At the start

0.00001844  aspnet_wp.exe	IOCTL_SERIAL_SET_HANDFLOW	USBSER001	SUCCESS	Shake:1 Replace:43 XonLimit:4096 XoffLimit:4096

And at the very end

0.00061153  aspnet_wp.exe	IOCTL_SERIAL_PURGE	USBSER001	SUCCESS	Purge: RXABORT RXCLEAR	
0.00004442  aspnet_wp.exe	IOCTL_SERIAL_PURGE	USBSER001	SUCCESS	Purge: TXABORT TXCLEAR

Has anyone got any tips on how to iron out these issues? I also notice that the phone is not responding back to the application with any acknowledgement when I issue a command so I suspect the problem is with the connection, not those messages at the end.