GSM Missed Call Automation

 Control Electrical appliances by a missed call with Sim 800L and Arduino 

Materials Required:

1-Arduino Nano

2-GSM module Sim 800L

3-5 volt Single channel relay

4-5Volt 2Ampere power supply

5-Terminal blocks

6- Red LED

7- 330 ohm resistance

Circuit Diagram:

Arduino code:

#include <SoftwareSerial.h>

const int relayPin=4;//connect digital pin 4 of Arduino to IN pin of Relay module

//bool relayStatus=1;

bool relayStatus=0;

const String phone="+971557407961";  // white list phone include +91 or your country code

SoftwareSerial gsmSerial(7,8);//Connect RXT pin of GSM module to D8 pin on Arduino 

                             // Connect TXD pin of GSM module to D7 pin of Arduino

String responseData;

String senderNumber;

void setup(){

  responseData.reserve(200);

  phone.reserve(20);

  pinMode(relayPin,OUTPUT);

  digitalWrite(relayPin,HIGH);

  //digitalWrite(relayPin,LOW);

  Serial.begin(9600);

  gsmSerial.begin(9600);

  delay(100);

  gsmSerial.write("AT\r");// because of SIM800L autobounding mode

  delay(100);

  gsmSerial.write("AT+IPR=9600\r");

  delay(100);

  gsmSerial.write("AT+CMGF=1\r");

  delay(500);

  gsmSerial.write("AT+CNMI=2,2,0,0,0\r");

  delay(100);

  Serial.print(gsmSerial.readString());

  gsmSerial.write("AT+CLIP=1\r\n");

  delay(100);

}

void loop(){

  if (gsmSerial.available()>0) {

    responseData = gsmSerial.readStringUntil('\n');

    Serial.println(responseData);

    parse();

    delay(1000);

  }

}

void parse(){

  if (responseData.indexOf("CLIP:")>0){

  senderNumber=responseData.substring(responseData.indexOf("+CLIP: ") +8,responseData.indexOf("+CLIP: ") +21); //PARSE CALLER ID 

  Serial.println("Caller number   :");

  Serial.println(senderNumber);

   if (senderNumber == phone){

    Serial.println("Sender number White list : ok");

    relayStatus=!relayStatus;

    digitalWrite(relayPin,relayStatus);

    gsmSerial.write("ATH\r");  // disconnect call & then send SMS

    gsmSerial.print("AT+CMGS=\""+phone+"\"\r");

    delay(1000);

    gsmSerial.print("DEVICE STATUS-");

  //gsmSerial.print("Relay status 1:off 0:on  ");

    gsmSerial.print(relayStatus);

    delay(200);

    gsmSerial.write(0x1A); //  ctrl+z to send message

    delay(100);

    

     }

    gsmSerial.write("ATH\r");

    delay(500);

  

  }

}