In this section, we will learn how we can send an SMS using our GSM Shield and Arduino. To send an SMS, we will use AT Commands once more. It is almost similar to the method used when calling with the GSM Shield.

Since we know how we can configure the GSM Shield and the Arduino, we will skip this part and go straight to the coding.

We need to include the SoftwareSerial library as we did before.

This time we will first set our GSM to be ready to send a text message. We can do this by printing the following line on the GSM.println() function:

GSMSerial.println("AT+CMGF=1"); 

Here, the AT+CMGF=1 command will set the GSM Shield to text mode. It is something similar to the Boolean operation - 1 can be replaced with 0 if we want to disable the text mode. It is a good practice to wait few moments after sending a command to the GSM Shield. We will wait 1 second, so we need to write delay(1000); after the GSMSerial.println(); command.

Now we will set the phone number to which we want...