#define Pin_Alarm D4 // Buzzer alarm connected to GPIO-14 or D5 of nodemcu
#define PIR_Sensor D35 // PIR sensor output connected to GPIO-5 or D1 of nodemcu
int Waiting_Time = 5000; // Time that your buzzer stay on in milliseconds, exemple; 10000 is 10 seconds

void setup() {
  pinMode(PIR_Sensor, INPUT); // PIR sensor as input
  pinMode(Pin_Alarm, OUTPUT); // Buzzer alaram as output
  digitalWrite(Pin_Alarm, LOW); // Initially buzzer off
}

void loop(){
  int state = digitalRead(PIR_Sensor); // Continuously check the state of PIR sensor
  delay(500); // Check state of PIR after every half second
  
  if(state == HIGH){ 
    digitalWrite (Pin_Alarm, HIGH); // If intrusion detected ring the buzzer delay(Waiting_Time); // Ring buzzer for time the you put in integer WaitTimer in seconds }
  else {
    digitalWrite (Pin_Alarm, LOW); // No intrusion Buzzer off }