CellularRadio module - delete all SMS

NETMF & Gadgeteer
1

Hi guys,
CellularRadio sometimes stops to work and I found that the reason is due to too many SMS stored in the SIM card (if I insert the sim card in a smartphone gives me the error: “sim card is full. Delete some sms.”)

Directly inside the SmsReceived event handler function I wrote this code:


Thread.Sleep(1500);
_Cell.DeleteAllSms();
Thread.Sleep(1000);

I was convinced that DeleteAllSms() method would erase all the sms inside the SIM but, obviously, it doesn’t…

The code inside that method (reading from gadgeteer 4.3 source) is the following:

public void DeleteAllSms()
{
this.SendATCommand("AT+CMGD=0,4");
}

Simple and clear!
Referring to the AT commands listed here 系统发生错误 at page 99 I verified that the AT+CMGD=0,4 command is correct.

In your opinion what is going wrong?

Maybe I need to call DeleteAllSms method outside of the SmsReceived event handler function?

2

I’ve not tried the DeleteAll method before. I tend to process the received SMS and then delete.

3

You suggest something like this?

4

A snippet from my old project…


        void cellularRadio_SmsReceived(CellularRadio sender, CellularRadio.Sms message)
        {
            usbSerial.Port.WriteLine("NEW SMS");
            usbSerial.Port.WriteLine("FROM: " + message.PhoneNumber);
            usbSerial.Port.WriteLine("MSG: " + message.Message);
            usbSerial.Port.WriteLine("WHEN: " + message.Timestamp.ToString());
            usbSerial.Port.WriteLine("STATUS: " + message.Status.ToString());
            usbSerial.Port.WriteLine("POS:" + message.Index.ToString());
            xbeeLED.BlinkRepeatedly(GT.Color.Blue);

            database.Open();
            nodeDatabase.UserLevel user = database.LogSMS(message.Timestamp, message.PhoneNumber, message.Message, nodeDatabase.SMSDirection.Recieved);
            switch (user)
            {
                case nodeDatabase.UserLevel.Unknown:
                    Debug.Print("Unknown user so probably SPAM");
                    break;
                case nodeDatabase.UserLevel.User:
                    Debug.Print("SMS From a User");
                    break;
                case nodeDatabase.UserLevel.Admin:
                    Debug.Print("SMS From an Admin");
                    break;
                case nodeDatabase.UserLevel.Creator:
                    Debug.Print("SMS From The Creator Himself");
                    break;
            }
            cellularRadio.DeleteSms(message.Index);

            database.Close();
        }

You can ignore the database calls etc.

Actually, looking at this project, I see that I was calling the DeleteAll method on startup where I would obtain a list of SMS, process each and then DeleteAll.

5

Unfortunately also deleting one SMS at a time doesn’t work.
If I insert the sim card in a smartphone I still see the received sms…

This is a snippet of my code:

Private Sub _Cell_SmsReceived(sender As CellularRadio, message As CellularRadio.Sms) Handles _Cell.SmsReceived
        Try
            ManageSmsReceived(message)
            _Cell.DeleteSms(message.Index)
        Catch ex As Exception
            WriteFileError("_Cell_SmsReceived", ex.Message & " (" & ex.GetType.ToString & ")")
        End Try
    End Sub

I’m not doing strange stuff

6

Rather than using the smartphone what do you get is you request the SMS list before and after you have deleted the messages?

                    cellularRadio.RequestSmsList(CellularRadio.SmsState.All);
7

I noticed that if I request the SMS list when there aren’t SMS the event SmsListReceived is not raised… (to me it would be more correct raise the event with a zero-length SMS’s array)

By requesting the SMS list I always get the list with all SMSs I sent (no matter if I request the list before or after I called the Delete method).

8

There is an AT command that tells the device where to store the messages and you can set this so that they don’t get store on the SIM.

The AT+CMGD command should delete them but I have seen the same issue with a SIM900 where it did not if on the SIM.

I am away from my main PC so I can’t get access to the Android code that does this.

1 Like
9

AT+CPMS=[,[,<mem3]]

10

I read at the documentation but the only one possible value for SIM900 is “SM” (so the SIM memory).
Searching in the gadgeteer source code there’s already this:

// Set the sms to be stored in the SIM card
this.SendATCommand("AT+CPMS=\"SM\"");

I think I haven’t understood your suggestion. What can I do? :slight_smile:

11

I’m at a loss as to why it doesn’t work for you. :think:

12

I made some “experiment”…

I checked the supported message storage areas and this is the module response:

I tried to delete messages using all these ways, always without success:

cellularRadio.DeleteAllSms();
cellularRadio.SendATCommand("AT+CMGDA=\"DEL ALL\"");
cellularRadio.SendATCommand("AT+CMGD=1,4");

I edited the standard gadgeteer driver to show each response received by cellular radio module… this allowed me to check many things and verify the response received for each command I sent.
Example:

[quote]CellularRadio : +CREG: 2
CellularRadio : +CSQ: 18,0
CellularRadio : +CPAS: 0
[/quote]

Each command gets always a response… AT+CMGD=0,4 respond “OK” so the command is being interpreted but, I don’t know why, not correctly executed even if it doesn’t returns ERROR.

Between all my attempts, once AT+CMGD=0,4 has worked properly and the 6 SMS stored were deleted!
Seems to be a race condition, because I found a condition that delete all sms correctly:

  • I added a breakpoint between commands “SendSms” and “DeleteAllSms”
  • I waited until the SMS arrived on my smarphone before executing “DeleteAllSms” (thanks to breakpoing)
  • I executed the “DeleteAllSms” and it worked

This is a snippet of my code:

Try
     _Cell.SendSms(strNumber, strText)
     Thread.Sleep(5000)
     _Cell.DeleteAllSms()
     Thread.Sleep(1000)
Catch ex As Exception
     Debug.Print(ex.ToString)
     WriteFileError("SendSmsMessage", ex.Message)
End Try

Before there was a Sleep of 1 second, now I set the Sleep at 5 seconds.
If I give enough time to send the SMS, the cellular radio module removes all SMS correctly.

But if the module requires more than 5 seconds to send the SMS?
What do you suggest to do to check when the module has completed to send?

Reading the documentation I found that after each SMS sent the module responds with “+CMGS: ” where is the message reference (index). When I receive this string I can raise an event “SmsSent”.
To you could be a good way?

13

For some reason I missed the fact that you were talking about Sending SMS from the module .

It would therefore make perfect sense to wait until the module responds with a “SMS Sent” event before trying to delete it.

14

Sent SMS should not be stored in the SIM. There is a different AT command for sending via the SIM. The normal AT+CMGS command should only send from the MT, not the SM module.