bathroom_monitor.ino

int led = 9;
int relay = 2;

int sensor = A0;
int sensorValue;

boolean occupied = false;

void setup() {
  pinMode(led, OUTPUT);
  pinMode(relay, OUTPUT);
  
  Serial.begin(9600);

    digitalWrite(led, LOW);
    digitalWrite(relay, LOW);
}

void loop() {
  sensorValue = analogRead(sensor);
  
  Serial.println(sensorValue);

  if (sensorValue < 400) {
    digitalWrite(led, HIGH);
    digitalWrite(relay, HIGH);
    
    if (!occupied) {
      delay(3000);
      occupied = true;
    }
  }
  else {
    digitalWrite(led, LOW);
    digitalWrite(relay, LOW);
    
    if (occupied) {
      delay(3000);
      occupied = false;
    }
  }

  delay(1000);
}