Fix sendSMS function

[WolfRorDev]

Fixes an error in the sendSMS function that made it impossible to send SMS.

[github-actions]

Memory usage change @ 740c109

Board	flash	%	RAM for global variables	%
arduino:mbed_portenta:envie_m7	N/A	N/A	N/A	N/A
arduino:renesas_portenta:portenta_c33	🔺 0 - +40	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/HTTPClient flash	%	examples/HTTPClient RAM for global variables	%	examples/HTTPSClient flash	%	examples/HTTPSClient RAM for global variables	%	examples/GetTime flash	%	examples/GetTime RAM for global variables	%	examples/GetLocation flash	%	examples/GetLocation RAM for global variables	%	examples/DeleteSMS flash	%	examples/DeleteSMS RAM for global variables	%	examples/ReceiveSMS flash	%	examples/ReceiveSMS RAM for global variables	%	examples/SendSMS flash	%	examples/SendSMS RAM for global variables	%	examples/ModemTerminal flash	%	examples/ModemTerminal RAM for global variables	%
arduino:mbed_portenta:envie_m7	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
arduino:renesas_portenta:portenta_c33	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	40	0.0	0	0.0	0	0.0	0	0.0

Click for full report CSV

Board,examples/HTTPClient<br>flash,%,examples/HTTPClient<br>RAM for global variables,%,examples/HTTPSClient<br>flash,%,examples/HTTPSClient<br>RAM for global variables,%,examples/GetTime<br>flash,%,examples/GetTime<br>RAM for global variables,%,examples/GetLocation<br>flash,%,examples/GetLocation<br>RAM for global variables,%,examples/DeleteSMS<br>flash,%,examples/DeleteSMS<br>RAM for global variables,%,examples/ReceiveSMS<br>flash,%,examples/ReceiveSMS<br>RAM for global variables,%,examples/SendSMS<br>flash,%,examples/SendSMS<br>RAM for global variables,%,examples/ModemTerminal<br>flash,%,examples/ModemTerminal<br>RAM for global variables,%
arduino:mbed_portenta:envie_m7,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A,N/A
arduino:renesas_portenta:portenta_c33,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,0,0.0,40,0.0,0,0.0,0,0.0,0,0.0

[cristidragomir97]

Hey @WolfRorDev, thanks for your contribution. In the begin method there's already a line that sets the SMS module into GSM mode, by sending "+CMGF=1", and this worked for me on both (EMEA and Global) modems. Could you please tell me which one you are using ? I'll investigate if the +CMGF=1 from the initialization is overridden by something, and then merge your request based on the result.

[aliphys]

The module is already set to text mode in the .begin() function.

Arduino_Cellular/src/ArduinoCellular.cpp

Lines 30 to 32 in 414d5e3

	// Set GSM module to text mode
	modem.sendAT("+CMGF=1");
	modem.waitResponse();

@cristidragomir97 would setting the text format again here increase the stability of the library?

[WolfRorDev]

Hey, I'm using the Global modem together with Arduino Portenta C33. I conducted many tests and found that I need to send the +CMGF=1 command before sending an SMS. I did many tests using the "SendSMS" example. After entering the PIN, my phone number, and enabling setDebugStream, I received the following response:

Unlocking SIM...
Connecting to network...
Connected!
Sending SMS...
Response: 0
Done.

The modem was tested in Poland 🇵🇱 using a SIM card from Orange Flex.

[aliphys]

After extensive testing, I can confirm that the fix provided here increases the stability of texts, when used together with the Pro 4G EMEA module and the Portenta C33 with a Telenor SIM Card in Sweden 🇸🇪 (only this configuration).

All texts go through, when patch provided by @WolfRorDev is applied.