I wrote code to send an SMS using my GSM phone which is attached to the computer through COM port. The code is below.
The problem is I do see that it is in the outbox of the phone and it actually appears to have been sent, but when I contact the recipient they say that I have not received the message.
I test the phone, and I create and send a message using only the phone and it works perfectly. However, when I do this with my code, it APPEARS to have been sent, and I am getting all the correct AT COMMAND responses from the phone, but the message is actually NOT sent.
Here is the code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.IO.Ports;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
SerialPort serialPort1;
int m_iTxtMsgState = 0;
const int NUM_MESSAGE_STATES = 4;
const string RESERVED_COM_1 = "COM1";
const string RESERVED_COM_4 = "COM4";
public Form1()
{
InitializeComponent();
this.Closing += new CancelEventHandler(Form1_Closing);
}
private void Form1_Load(object sender, EventArgs e)
{
serialPort1 = new SerialPort(GetUSBComPort());
if (serialPort1.IsOpen)
{
serialPort1.Close();
}
serialPort1.Open();
//ThreadStart myThreadDelegate = new ThreadStart(ReceiveAndOutput);
//Thread myThread = new Thread(myThreadDelegate);
//myThread.Start();
this.serialPort1.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);
}
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
serialPort1.Close();
}
private void SendLine(string sLine)
{
serialPort1.Write(sLine);
sLine = sLine.Replace("\u001A", "");
consoleOut.Text += sLine;
}
public void DoWork()
{
ProcessMessageState();
}
public void ProcessMessageState()
{
switch (m_iTxtMsgState)
{
case 0:
m_iTxtMsgState = 1;
SendLine("AT\r\n"); //NOTE: SendLine must be the last thing called in all of these!
break;
case 1:
m_iTxtMsgState = 2;
SendLine("AT+CMGF=1\r\n");
break;
case 2:
m_iTxtMsgState = 3;
SendLine("AT+CMGW=" + Convert.ToChar(34) + "+9737387467" + Convert.ToChar(34) + "\r\n");
break;
case 3:
m_iTxtMsgState = 4;
SendLine("A simple demo of SMS text messaging." + Convert.ToChar(26));
break;
case 4:
m_iTxtMsgState = 5;
break;
case 5:
m_iTxtMsgState = NUM_MESSAGE_STATES;
break;
}
}
private string GetStoredSMSID()
{
return null;
}
/* //I don't think this part does anything
private void serialPort1_DataReceived_1(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
string response = serialPort1.ReadLine();
this.BeginInvoke(new MethodInvoker(() => textBox1.AppendText(response + "\r\n")));
}
*/
void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
try
{
Thread.Sleep(500);
char[] msg;
msg = new char[613];
int iNumToRead = serialPort1.BytesToRead;
serialPort1.Read(msg, 0, iNumToRead);
string response = new string(msg);
this.BeginInvoke(new MethodInvoker(() => textBox1.AppendText(response + "\r\n")));
serialPort1.DiscardInBuffer();
if (m_iTxtMsgState == 4)
{
int pos_cmgw = response.IndexOf("+CMGW:");
string cmgw_num = response.Substring(pos_cmgw + 7, 4);
SendLine("AT+CMSS=" + cmgw_num + "\r\n");
//stop listening to messages received
}
if (m_iTxtMsgState < NUM_MESSAGE_STATES)
{
ProcessMessageState();
}
}
catch
{ }
}
private void button1_Click(object sender, EventArgs e)
{
m_iTxtMsgState = 0;
DoWork();
}
private void button2_Click(object sender, EventArgs e)
{
string[] sPorts = SerialPort.GetPortNames();
foreach (string port in sPorts)
{
consoleOut.Text += port + "\r\n";
}
}
private string GetUSBComPort()
{
string[] sPorts = SerialPort.GetPortNames();
foreach (string port in sPorts)
{
if (port != RESERVED_COM_1
&& port != RESERVED_COM_4)
{
return port;
}
}
return null;
}
}