void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(2, INPUT_PULLUP);
  pinMode(4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int a=digitalRead(2);
  Serial.println(2);
 
  if(a==HIGH){
    Serial.println("Motion Detected");
    digitalWrite(4, HIGH);
    delay(70);
    digitalWrite(4, LOW);
    delay(70);
    tone(9, 262, 250);
    delay(500);
    noTone(9);
  }

  if(a==LOW){
    Serial.println("No Motion Detected");
  }
  delay(10);
}