// Pin definitions
const int trigPin = 5;
const int echoPin = 18;
const int pirPin  = 19;

// Variables for distance and motion
long duration;
float distance;
bool motionDetected = false;

void setup() {
  Serial.begin(115200);

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(pirPin, INPUT);

  Serial.println("ESP32 Ultrasonic + PIR Sensor Initialized");
}

void loop() {
  // Read PIR motion sensor
  motionDetected = digitalRead(pirPin);

  if (motionDetected) {
    Serial.println("Motion Detected!");

    // Trigger ultrasonic sensor
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Read echo pin
    duration = pulseIn(echoPin, HIGH);

    // Calculate distance (cm)
    distance = duration * 0.034 / 2;

    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" cm");
  } else {
    Serial.println("No Motion Detected.");
  }

  delay(1000); // Wait before next read
}