AT commands Send/receive SMS

Question

I am new to AT commands. I am using Nokia E71 to send and receive SMS. I am designing an application for sending SMS, but my code is not working.

using Syste         


        

Answer 1

Why dont you open the port connection in the form_load() itself, later you can close it at the end as you did.

And do these too in Form_Load():

string cmd = "AT";
port.WriteLine(cmd + "\r");
port.Write(cmd + "\r");
port.WriteLine("AT+CMGF=1");

And simplifying the sms sending code:

port.WriteLine("AT+CMGS=\"" + PhNumber + "\"");
port.Write(Message + char.ConvertFromUtf32(26));

Answer 2

Try it this way.. You are not opening the connection to the serial port. I have tried it and it is working fine for me.

 private void button1_Click(object sender, EventArgs e)
 {
     this.serialPort = new SerialPort();
     this.serialPort.PortName = "COM5";
     this.serialPort.BaudRate = 9600;
     this.serialPort.Parity = Parity.None;
     this.serialPort.DataBits = 8;
     this.serialPort.StopBits = StopBits.One;
     this.serialPort.Handshake = Handshake.RequestToSend;
     this.serialPort.DtrEnable = true;
     this.serialPort.RtsEnable = true;
     this.serialPort.NewLine = System.Environment.NewLine;
     serialPort.Open();
     send_sms();
 }
 public bool send_sms()
 {
     String SMSMessage = "gsm MESSAGE FROM .NET C#";
     String CellNumber = "+9233333333333";
     String messageToSend = null;
     if (SMSMessage.Length <= 160)
     {
         messageToSend = SMSMessage;
     }
     else
     {
         messageToSend = SMSMessage.Substring(0, 160);
     }
     if (serialPort.IsOpen)
     {
         this.serialPort.WriteLine(@"AT" + (char)(13));
         Thread.Sleep(200);
         this.serialPort.WriteLine("AT+CMGF=1" + (char)(13));
         Thread.Sleep(200);
         this.serialPort.WriteLine(@"AT+CMGS=""" + CellNumber + @"""" + (char)(13));
         Thread.Sleep(200);
         this.serialPort.WriteLine(SMSMessage + (char)(26));
         return true;
         }
     return false;
 }

Answer 3

Here's my code

using System;
using System.IO.Ports;
using System.Threading;
using System.Windows.Forms;

namespace CSharp_SMS
{
  public partial class Form_SMS_Sender : Form
  {
    private SerialPort _serialPort;
    public Form_SMS_Sender()
    {
        InitializeComponent();
    }

    private void buttonSend_Click(object sender, EventArgs e)
    {
        string number = textBoxNumber.Text;
        string message = textBoxMessage.Text;

        //Replace "COM7"withcorresponding port name
        _serialPort = new SerialPort("COM7", 115200);   

        Thread.Sleep(1000);

        _serialPort.Open();

        Thread.Sleep(1000);

        _serialPort.Write("AT+CMGF=1\r");

        Thread.Sleep(1000);

        _serialPort.Write("AT+CMGS=\"" + number + "\"\r\n");

        Thread.Sleep(1000);

        _serialPort.Write(message + "\x1A");

        Thread.Sleep(1000);

        labelStatus.Text = "Status: Message sent";

        _serialPort.Close();
        }
    }
}

Here's a link http://circuitfreak.blogspot.com/2013/03/c-programming-sending-sms-using-at.html