#include <Arduino.h>
// leds and switches
const byte led_pin2 = 13;
const byte led_pin1 =11;
const byte button_pin2= 7;
//const byte button_pin1 =2;
// boolean for inputs states
//volatile bool D2 =LOW;
//volatile bool D7 =LOW;

void setup() {
  pinMode(led_pin2, OUTPUT);
  pinMode(led_pin1, OUTPUT);
  //pinMode(button_pin1, INPUT_PULLUP);
  pinMode(button_pin2, INPUT_PULLUP);
  // Enable  PCICR2 bit3 = 1 Port D
  PCICR |= 0x04;
  //Enable PCINT18 & PCINT23 (Pins D2 & D7)
  PCMSK2 |= 0x80;
}

void loop() {
  for(int y=0;y<4;y++){
    digitalWrite(led_pin1, HIGH);
    delay(500);
    digitalWrite(led_pin1, LOW);
    delay(500);
  }
}

ISR(PCINT2_vect){
  if(digitalRead(button_pin2)==0){
    digitalWrite(led_pin2, HIGH);
  }
  else{
    digitalWrite(led_pin2, LOW);
  }
}