/* WREBOTICS Security Alarm V1 1/26/2024 */
// Constants for pin assignments
const int LED_PIN = 7;
const int TRIGGER_PIN = 8;
const int ECHO_PIN = 9;
const int BUZZER_PIN = 11;

const int MAX_DISTANCE = 75; // Maximum distance to trigger alarm (in centimeters)

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(9600);
}
void loop() {
  // Initiate the ultrasonic pulse
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);

  // Measure the duration of the echo pulse
  long duration = pulseIn(ECHO_PIN, HIGH);
  int distance = duration * 0.034 / 2; // Calculate the distance

  // Display the distance
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Check if the distance is within the 'movement detected' range
  if (distance <= MAX_DISTANCE) {
    digitalWrite(LED_PIN, HIGH); // Turn on LED
    Serial.println("Movement Detected");
    tone(BUZZER_PIN, 330); // Emit an alternating tone
    delay(400);
    tone(BUZZER_PIN, 250);
    delay(400);
  } else {
    digitalWrite(LED_PIN, LOW); // Turn off LED
    noTone(BUZZER_PIN); // Stop emitting tone
  }
  // Short delay before the next loop iteration
  delay(50);
}