SEND SMS USING AT COMMANDS FROM MOBILE PHONE CONNECTED TO YOUR PC :ASP.NET C#

AT commands is used to communicate with gsm modem.There are many type of gsm modems,so that the AT commend also vary with the model we use.By AT commend mean Attention Terminal.we can communicate with a mobile phone connected to your PC using Hyper Terminals .First of all for starting a communication with gsm modem or mobile phone

we will send an "AT" command to the gsm modem,gsm modem respond it with an "OK" command. For sending an sms from nokia mobile we need to set the message format to text, for that we send the command "AT+CMGF=1",the phone also responses it with an "OK" command. then we will send the recipient mobile number to the gsm modem using "AT+CMGS="123456789"" after this command we will send the msg and for notifying the end of msg we click ctrl+z.

programming this using ASP.NET c# we have to declare a serial port

private SerialPort SMSPort;

send the commands through this serial port

char cr = (char)13;

char lf = (char)10;

SMSPort.WriteLine("AT");

Thread.Sleep(4);

SMSPort.Write("" + cr + lf);

Thread.Sleep(100);

Thread.Sleep(100);

Thread.Sleep(100);

SMSPort.Write("ATE0");

Thread.Sleep(25);

SMSPort.Write("" + cr + lf);

Thread.Sleep(25);

SMSPort.Write("AT+CMGF=1");

SMSPort.Write("" + cr + lf);

Thread.Sleep(25);

SMSPort.Write("AT+CMGS=");

SMSPort.Write("" + (char)34);

SMSPort.Write(SMSMessage);

SMSPort.Write("" + (char)34);

Thread.Sleep(100);

SMSPort.Write("" + cr + lf);

Thread.Sleep(200);

SMSPort.Write(msg);

Thread.Sleep(250);

SMSPort.Write("" + (char)26);

Here we use the ascii value of ctrl+z ,26 to notify the end of the msg.