Automated Door Lock System Using Arduino

This automated door lock system is designed to enhance security by using an Arduino microcontroller, a servo motor, and an RFID or keypad module to control access.

Key Components & Their Roles

1. Arduino Uno/Nano – Microcontroller that processes input and controls the locking mechanism.
2. Servo Motor – Moves the lock mechanism based on authentication.
3. RFID Module or Keypad – Allows users to unlock the door using an RFID card or password.
4. LCD Display (Optional) – Shows status messages like “Access Granted” or “Access Denied.”
5. Buzzer – Provides an audible alert when access is granted or denied.
6. Relay Module (Optional) – Can control an electromagnetic lock for enhanced security.
7. Power Supply (9V or 12V) – Provides power to the system.

Working Principle

• The RFID module or keypad receives user input.
• The Arduino processes the input and compares it with stored credentials.
• If the input matches, the servo motor rotates to unlock the door.
• If the input does not match, the buzzer sounds and access is denied.
• The LCD display (if included) shows relevant messages.

Wiring Connections

Arduino Code Example

#include <Servo.h>

Servo myServo;            // Create a servo object
int irSensorPin = 2;      // IR sensor output pin
int ledPin = 8;           // LED pin
int buzzerPin = 9;        // Buzzer pin
int servoPin = 3;         // Servo motor control pin
int personDetected = 0;   // Variable to store IR sensor value

void setup() {
  pinMode(irSensorPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  myServo.attach(servoPin);
  myServo.write(0);       // Initial position (Locked)
  Serial.begin(9600);
}

void loop() {
  personDetected = digitalRead(irSensorPin);

  if (personDetected == HIGH) {       // If person detected
    digitalWrite(ledPin, HIGH);       // Turn on LED
    myServo.write(90);                // Unlock position (90 degrees)
    Serial.println("Door Unlocked!");
    delay(5000);                      // Keeps the door unlocked for 5 seconds
    myServo.write(0);                 // Lock the door again
    digitalWrite(ledPin, LOW);        // Turn off LED
    Serial.println("Door Locked!");
  } else {
    digitalWrite(buzzerPin, HIGH);    // Activate buzzer if access attempt fails
    delay(1000);
    digitalWrite(buzzerPin, LOW);
    Serial.println("Unauthorized Access Attempt!");
  }

  delay(1000);                        // Small delay for sensor stabilization
}

Advantages of This System

✅ Enhanced Security – Prevents unauthorized access.
✅ Customizable Access Methods – Supports RFID, keypad, or fingerprint modules.
✅ Low Power Consumption – Operates efficiently with minimal energy.
✅ Easy to Build – Uses basic electronic components.