How to Create a Doorlock IoT with Raspberry Pi

This tutorial will walk you through crafting an automated door lock system that you can effortlessly control from your phone or a web browser. This project harnesses the power of a Raspberry Pi, a servo motor, and a simple web interface built using Flask.

Gathering Your Arsenal: The Essential Components

Before embarking on this exciting journey, let's gather the necessary tools and materials:

Hardware:

• Raspberry Pi: Any model will suffice for this project.

• Servo Motor: This mechanical marvel will be the muscle behind the door lock mechanism.

• Jumper Wires: These versatile wires will serve as the connectors between your components.

• Breadboard: A convenient platform for prototyping and experimenting with your circuits.

• External 5V Power Supply: Providing the juice for your servo motor.

• MicroSD Card: At least 8GB in size, pre-loaded with Raspberry Pi OS.

• Raspberry Pi Case (Optional): To keep your Pi safe and sound.

Software:

• Python 3: The programming language that will breathe life into your project.

• Flask: A lightweight web framework that will empower you to build the control interface.

• RPi.GPIO Library: Essential for controlling the GPIO pins on your Raspberry Pi, enabling communication with the servo motor.

• Your GitHub Repo: A cloud-based repository to safely store and share your final code.

Step 1: Connecting the Hardware: The Foundation of Your Smart Lock

The first step is to establish a connection between your Raspberry Pi and the servo motor. This connection will enable the Pi to send commands to the servo, controlling the door lock mechanism.

• Powering Up: Connect the red wire from the servo motor to a 5V pin on your Raspberry Pi. This provides the necessary power for the motor to function.

• Grounding the Circuit: Attach the black or brown wire (ground) from the servo to a ground (GND) pin on the Raspberry Pi. This creates a stable electrical path for the circuit.

• The Control Link: Connect the control wire (usually yellow or white) to GPIO 17 (pin 11) on your Raspberry Pi. This pin acts as the communication channel between the Pi and the servo.

Step 2: Equipping Your Pi: Installing Necessary Libraries

Now, it's time to equip your Raspberry Pi with the software tools needed for this project. We will install two essential libraries: Flask and RPi.GPIO.

• Updating Your System: Start by ensuring your system is up to date with the latest software packages. Run the following command in your Raspberry Pi's terminal (Bash):

        sudo apt-get update
      

  
  

• Installing Flask: Flask is a powerful framework for building web applications. Install it with the following command:

        sudo apt-get install python3-flask
      

  
  

• Adding RPi.GPIO: This library facilitates communication with the Raspberry Pi's GPIO pins. Install it with the following command:

        pip install RPi.GPIO
      

  
  

Step 3: Scripting the Servo Control: Bringing Your Door Lock to Life

In this crucial step, you'll create a Python script that commands the servo motor to lock and unlock the door. This script will form the heart of your smart lock's functionality.

Filename: door_lock.py

import RPi.GPIO as GPIO
import time

# Set GPIO mode to BCM
GPIO.setmode(GPIO.BCM)

# Define the GPIO pin connected to the servo motor control wire
servo_pin = 17

# Set up the GPIO pin as an output
GPIO.setup(servo_pin, GPIO.OUT)

# Define the servo motor's pulse width range
servo_range = (1.5, 2.5)  # Adjust these values for your specific servo

# Create a PWM object with a frequency of 50Hz
pwm = GPIO.PWM(servo_pin, 50)

# Function to lock the door
def lock():
    print("Locking the door...")
    pwm.start(servo_range[0])  # Set the servo to the lock position
    time.sleep(1)
    pwm.stop()

# Function to unlock the door
def unlock():
    print("Unlocking the door...")
    pwm.start(servo_range[1])  # Set the servo to the unlock position
    time.sleep(1)
    pwm.stop()

# Cleanup GPIO pins on exit
GPIO.cleanup()

# Example usage:
# lock()
# unlock()
    

This code allows the servo motor to lock and unlock the door based on the signal sent from the Raspberry Pi.

Step 4: Building Your Web Interface: Controlling Your Door Lock Remotely

Now, we'll create a simple Flask web app that acts as a remote control for your door lock. This web app will feature two buttons: one to lock the door and another to unlock it.

Filename: app.py

from flask import Flask, render_template, request
import door_lock  # Import your door_lock.py script

app = Flask(__name__)

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/lock', methods=['POST'])
def lock_door():
    door_lock.lock()
    return 'Door locked!'

@app.route('/unlock', methods=['POST'])
def unlock_door():
    door_lock.unlock()
    return 'Door unlocked!'

if __name__ == '__main__':
    app.run(debug=True, host='0.0.0.0')
    

This Flask app listens for requests to lock or unlock the door and triggers the appropriate function from the door_lock.py script.

Step 5: Designing Your Web Interface: A User-Friendly Gateway

Now, let's create a simple HTML interface that you can access from your phone or any web browser to control your door lock. Place this HTML file in a templates folder in your project directory.

Filename: index.html

<!DOCTYPE html>
<html>
<head>
    <title>Smart Door Lock</title>
</head>
<body>
    <h1>Smart Door Lock</h1>
    <form method="POST" action="/lock">
        <button type="submit">Lock Door</button>
    </form>
    <form method="POST" action="/unlock">
        <button type="submit">Unlock Door</button>
    </form>
</body>
</html>
    

Step 6: Launching Your System: Unlocking the Power of Your Smart Door Lock

To get your system up and running, start the Flask app on your Raspberry Pi. Run the following command in your Pi's terminal:

      python3 app.py
    

Now, open a browser on your phone or computer and navigate to http://<Your-Raspberry-Pi-IP>:5000. You should see the web interface with the lock and unlock buttons.

Step 7: Adding Advanced Features: Elevate Your Smart Door Lock

With the core system in place, let's explore some exciting ways to enhance your smart door lock and unlock its full potential:

• Authentication: Fortify your system with a username and password to prevent unauthorized access.

• Voice Integration: Integrate your smart lock with popular voice assistants like Google Assistant or Amazon Alexa for hands-free control.

• Mobile App: Create a dedicated mobile app using frameworks like FlutterFlow to seamlessly control your door lock from your phone.

• Notifications: Implement a system that notifies you via SMS or push notifications when the door is locked or unlocked.

Conclusion

By following this guide, you have successfully built a smart door lock system that you can control from any device with an internet connection. This project not only enhances the security of your home but also brings a level of convenience that is unmatched.

With its customizable nature, you have the power to expand its capabilities further by adding mobile app integration, voice assistant compatibility, and advanced security features. The future of door security is in your hands!