// Pin assignments
const int lightSensorPin = A0;  // LDR connected to A0 for detecting light (CFL/natural light)
const int soundSensorPin = A1;  // Sound sensor connected to A1
const int ledPin = 7;           // LED connected to pin 7 (representing the night lamp bulb)
const int servoPin = 9;         // Servo motor connected to pin 9 (for door lock)

int lightSensorValue = 0;       // Variable to store the LDR value
int soundSensorValue = 0;       // Variable to store the sound sensor value

int lightThreshold = 300;       // Threshold for LDR to detect darkness (adjust as needed)
int soundThreshold = 500;       // Threshold for sound detection (adjust as needed)

// PWM values for servo positions
int lockPosition = 100;         // PWM value for the locked position (approx. 90 degrees)
int unlockPosition = 0;        // PWM value for the unlocked position (approx. 0 degrees)

void setup() {
  pinMode(ledPin, OUTPUT);      // Set LED pin as an output
  pinMode(servoPin, OUTPUT);    // Set the servo pin as an output
  digitalWrite(ledPin, LOW);    // Turn off the LED initially

  Serial.begin(9600);           // Start serial communication for debugging
  Serial.println("System started. Monitoring light, sound, and door lock...");
}

void loop() {
  lightSensorValue = analogRead(lightSensorPin);  // Read the LDR value
  soundSensorValue = analogRead(soundSensorPin);  // Read the sound sensor value

  // Display the light and sound values on the Serial Monitor for debugging
  Serial.print("Light: ");
  Serial.print(lightSensorValue); // Print LDR value for debugging
  Serial.print(" | Sound: ");
  Serial.println(soundSensorValue); // Print sound sensor value for debugging

  // Check if sound is detected
  if (soundSensorValue > soundThreshold) {
    Serial.println("Don't Disturb! Locking door...");
    
    // Lock the door (rotate the servo to lock position)
    lockDoor();  // Function to lock the door (PWM for 90 degrees)

    // Check if the room is dark (low LUX)
    if (lightSensorValue > lightThreshold) {
      digitalWrite(ledPin, HIGH);  // Turn on the LED (night lamp)
    } else {
      digitalWrite(ledPin, LOW);   // Keep the LED off if LUX is high
    }
  } else {
    // If no sound is detected
    digitalWrite(ledPin, LOW);    // Turn off the LED
    
    // Unlock the door (rotate the servo to unlock position)
    unlockDoor();  // Function to unlock the door (PWM for 0 degrees)
  }

  delay(500); // Small delay for stability
}

// Function to lock the door (send PWM signal to servo)
void lockDoor() {
  analogWrite(servoPin, lockPosition);  // Send PWM signal to lock (90 degrees)
  delay(1000);  // Hold the position for 1 second
  analogWrite(servoPin, 0);  // Stop sending PWM signal
}

// Function to unlock the door (send PWM signal to servo)
void unlockDoor() {
  analogWrite(servoPin, unlockPosition);  // Send PWM signal to unlock (0 degrees)
  delay(1000);  // Hold the position for 1 second
  analogWrite(servoPin, 0);  // Stop sending PWM signal
}