[RESOLVED] SMS sending only working in Debug mode

hello. i have a small application that is meant to send out smses using AT commands in Vb .net.
the code seems to be working fine when i am debugging but when i run the normal way no sms is send. the following is my code, please help me see where i am going wrong.

dim smsPort As New SerialPort

smsPort.PortName = "COM18"
smsPort.BaudRate = "921600"
smsPort.Parity = Parity.None
smsPort.DataBits = 8
smsPort.StopBits = StopBits.One
smsPort.Handshake = Handshake.RequestToSend
smsPort.DtrEnable = True
smsPort.RtsEnable = True
smsPort.NewLine = vbCrLf

If Not (smsPort.IsOpen = True) Then
smsPort.Open()
End If

smsPort.WriteLine("AT" & vbCrLf)
smsPort.WriteLine("AT+CMGF=1" & vbCrLf)
smsPort.WriteLine("AT+CMGS=" + Chr(34) + Trim(TextBoxMobileNumber.Text) + Chr(34) + vbCrLf)
smsPort.WriteLine(Trim(TextBoxMessage.Text) + vbCrLf + Chr(26))


If smsPort.IsOpen = True Then
smsPort.Close()
End If

If you are doing this on the same machine, likely you are opending the port but not always closing it.
You need to add some error trapping to tell you what the problem is. We don't have your modem or your settings to test it :). Have you tried running it as a .exe after a reboot (ie BEFORE running it in debug).

the problem is its not giving any error at all.

Show the whole method and how you call it, not just the part in question.

thats pretty much everything..of course with beginning and end of sub for the button click event.if i step through in code an sms is send but if i run without debug nothing is send. i will give the code again anyway as follows,

Public smsPort As New SerialPort
Private Sub ButtonSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonSend.Click
smsPort.PortName = "COM18"
smsPort.BaudRate = "921600"
smsPort.Parity = Parity.None
smsPort.DataBits = 8
smsPort.StopBits = StopBits.One
smsPort.Handshake = Handshake.RequestToSend
smsPort.DtrEnable = True
smsPort.RtsEnable = True
smsPort.NewLine = vbCrLf

If Not (smsPort.IsOpen = True) Then
smsPort.Open()
End If

smsPort.WriteLine("AT" & vbCrLf)
smsPort.WriteLine("AT+CMGF=1" & vbCrLf)
smsPort.WriteLine("AT+CMGS=" + Chr(34) + Trim(TextBoxMobileNumber.Text) + Chr(34) + vbCrLf)
smsPort.WriteLine(Trim(TextBoxMessage.Text) + vbCrLf + Chr(26))

If smsPort.IsOpen = True Then
smsPort.Close()
End If


MsgBox("message sending complete")
End Sub

There is nothing in your code that makes any difference in run mode. How do you run it "the normal way"? Are you using any breakpoints which might be slowing down the execution?

finally i stumbled on a solution to my problem. i have added a "sleeper" code before and after writing the message as follows,

smsPort.WriteLine("AT" & vbCrLf)
smsPort.WriteLine("AT+CMGF=1" & vbCrLf)
smsPort.WriteLine("AT+CMGS=" + Chr(34) + Trim(txtRecipient.Text) + Chr(34) + vbCrLf)

System.Threading.Thread.Sleep(200)
smsPort.WriteLine(Trim(txtMessage.Text) + vbCrLf + Chr(26))
System.Threading.Thread.Sleep(200)

someone else used this code and it works for me though i dont quite understand it. i was thinking more along the lines of a refresh but looks like this sleeper code did it.

Well was on the right track, if you were stepping through the code in debug, it would slow down the code. Sending the data through to fast to the modem would make it believe it is all one command.

i see..it makes sense...perhaps you can help me solve my next question. i have posted it as another thread. now i am trying to loop through a list of numbers sending smses and it only sends to the first one. the loop is working fine but the other numbers are not receiving anything.