/********* Complete project details at http://randomnerdtutorials.com *********/ #include // Configure software serial port SoftwareSerial SIM900(7, 8); void setup() { // Arduino communicates with SIM900 GSM shield at a baud rate of 19200 // Make sure that corresponds to the baud rate of your module SIM900.begin(19200); // Give time to your GSM shield log on to network delay(20000); // Send the SMS sendSMS(); } void loop() { } void sendSMS() { // AT command to set SIM900 to SMS mode SIM900.print("AT+CMGF=1\r"); delay(100); // REPLACE THE X's WITH THE RECIPIENT'S MOBILE NUMBER // USE INTERNATIONAL FORMAT CODE FOR MOBILE NUMBERS SIM900.println("AT+CMGS=\"+XXXXXXXXXXXX\""); delay(100); // REPLACE WITH YOUR OWN SMS MESSAGE CONTENT SIM900.println("Message example from Arduino Uno."); delay(100); // End AT command with a ^Z, ASCII code 26 SIM900.println((char)26); delay(100); SIM900.println(); // Give module time to send SMS delay(5000); }