Arduino code for Send and Receive SMS using GSM module.

This is a example program to send and receive sms using gsm module and arduino. I tested these code with the SIM900A gsm module.

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/*

Press--> t: To Send Text Message.

r: To Receive Text Message.

*/

#include <SoftwareSerial.h>

SoftwareSerial mySerial(7, 8);

void setup()

{

  mySerial.begin(9600);               // the GPRS baud rate   

  Serial.begin(9600);    // the GPRS baud rate 

  delay(500);

}

void loop()

{

  if (Serial.available()>0)

   switch(Serial.read())

  {

    case 't':

      SendTextMessage();

      break;

    case 'r':

      RecieveTextMessage();

      break;

  }

 if (mySerial.available()>0)

   Serial.write(mySerial.read());

}

///SendTextMessage()

///this function is to send a sms

 void SendTextMessage()

{

  mySerial.println("AT+CMGF=1");    //Because we want to send the SMS in text mode

  delay(100);

  mySerial.println("AT+CMGS=\"+91******\"\r"); // change to the phone number you using 

  delay(100);

  mySerial.println("A test message!");//the content of the message

  delay(100);

  

  mySerial.println((char)26);//the ASCII code of the ctrl+z is 26

  delay(100);

}

///RecieveTextMessage()

///this function is to show received a sms

 void RecieveTextMessage()

{

  mySerial.println("AT+CMGF=1\r");

  delay(200);

  

  //mySerial.println("AT+CNMI=2,2,0,0,0");

  //delay(200);

   

  //mySerial.println("AT+CSCS=\"GSM\"\r");

  //delay(100);

   

  mySerial.println("AT+CMGL=\"ALL\"\r"); // to read ALL the SMS in text mode

  delay(200);

  //mySerial.println("AT+CMGR=3\r");//  to read the SMS in text mode from location x

  //delay(100);

}

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