#include <avr/sleep.h>//this AVR library contains the methods that controls the sleep modes
#include <avr/wdt.h>
#define interruptPin 2 //Pin we are going to use to wake up the Arduino
int lspwr = 3;
int lsoutput = 4;
int relay = 5;

void setup() {
  Serial.begin(115200);//Start Serial Comunication
  pinMode(LED_BUILTIN,OUTPUT);//We use the led on pin 13 to indecate when Arduino is A sleep
  pinMode(interruptPin,INPUT_PULLUP);//Set pin d2 to input using the buildin pullup resistor
  pinMode(lspwr, OUTPUT);
  pinMode(lsoutput, INPUT);
  pinMode(relay, OUTPUT);
  digitalWrite(LED_BUILTIN,HIGH);//turning LED on
  int a;
}

void loop() {
 delay(5000);//wait 5 seconds before going to sleep
 Going_To_Sleep();
}

void Going_To_Sleep(){
    sleep_enable();//Enabling sleep mode
    attachInterrupt(0, wakeUp, CHANGE);//attaching a interrupt to pin d2
    set_sleep_mode(SLEEP_MODE_PWR_DOWN);//Setting the sleep mode, in our case full sleep
    digitalWrite(LED_BUILTIN,LOW);//turning LED off
    delay(1000); //wait a second to allow the led to be turned off before going to sleep
    sleep_cpu();//activating sleep mode
    Serial.println("just woke up!");//next line of code executed after the interrupt 
    digitalWrite(LED_BUILTIN,HIGH);//turning LED on
  }

void wakeUp(){
  Serial.println("Interrrupt Fired");//Print message to serial monitor
   sleep_disable();//Disable sleep mode
  detachInterrupt(0); //Removes the interrupt from pin 2;
 sleep_enable(); // Enable sleep mode
  set_sleep_mode(SLEEP_MODE_PWR_DOWN); // Set sleep mode to power down
  digitalWrite(LED_BUILTIN,LOW); // turn off LED
  delay(1000); // wait a second to allow LED to turn off

  while (digitalRead(lsoutput)==LOW) {
    digitalWrite(lspower, LOW);
    for (int i = 0; i < 8; i++) {
    sleep_cpu(); // activate sleep mode for 8 seconds
    };
    digitalWrite(lspower, HIGH); 
    delay(50); // give ls time to pwr up
  }
  
  digitalWrite(realy, HIGH);
  delay(2000); //open relay for 2 seconds
  digitalWrite(relay, LOW);

 }
}