#define PIR_PIN 9

bool previousState = LOW;

void setup() {
  Serial.begin(9600);
  pinMode(PIR_PIN, INPUT);

  Serial.println("PIR Sensor Ready");
}

void loop() {
  bool currentState = digitalRead(PIR_PIN);

  if (currentState != previousState) {

    if (currentState == HIGH) {
      Serial.println("Motion Detected!");
    }
    else {
      Serial.println("Motion Stopped");
    }

    previousState = currentState;
  }
}