#define led_pin 26
#define motion_sensor 27
#define buzzer 25

unsigned long now;                     
volatile bool StartTime = false;       
volatile unsigned long lastTrigger;    

const unsigned long interval = 2 * 1000UL;

bool printMotion = false;

void ARDUINO_ISR_ATTR motionIsr()
{
  lastTrigger = millis();
  StartTime = true;
}

void setup()
{
  Serial.begin(115200);
  pinMode(led_pin, OUTPUT);
  pinMode(buzzer, OUTPUT);
  digitalWrite(buzzer, LOW);
  digitalWrite(led_pin, LOW);
  pinMode(motion_sensor, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(motion_sensor), motionIsr, RISING);
}

void loop()
{
  now = millis();

  if (StartTime == true && !printMotion)   
  {
    digitalWrite(buzzer, HIGH);
    Serial.println("nagar bsdka aagya");     
    digitalWrite(led_pin, HIGH);
    printMotion = true;
  }

  if (StartTime && (now - lastTrigger > interval))
  {
    Serial.println("Nagar gya");
    digitalWrite(led_pin, LOW);
    digitalWrite(buzzer, LOW);
    printMotion = false;
    StartTime = false;                    
  }
}