Smart Home Automation Prototype - Complete Guide

This project demonstrates a comprehensive home automation system using ESP32 microcontroller that can control lighting, monitor security, track environmental conditions, and manage appliances remotely via a mobile app.

Key Features

Components Required

Main Controller

Sensors

Output Devices

Additional Components

Total Budget Estimate

Category	Cost Range (LKR)
Main Controller	2,500 - 3,500
Sensors	1,730 - 2,500
Output Devices	1,800 - 3,300
Additional Components	1,800 - 3,600
Total Project Cost	7,830 - 12,900

Note: Prices may vary based on supplier and quality. Budget suitable for student projects.

Step-by-Step Implementation

Phase 1: Hardware Setup

Step 1: ESP32 Setup

Step 2: Sensor Connections

PIR Motion Sensor:
- VCC → 3.3V
- GND → GND
- OUT → GPIO 13

DHT22 Temperature Sensor:
- VCC → 3.3V
- GND → GND
- DATA → GPIO 14

LDR (Light Sensor):
- One end → 3.3V
- Other end → GPIO 35 (ADC pin)
- 10kΩ resistor between GPIO 35 and GND

Step 3: Output Device Connections

Relay Module:
- VCC → 5V
- GND → GND
- IN1 → GPIO 25 (Light Control)
- IN2 → GPIO 26 (Fan Control)
- IN3 → GPIO 27 (Heater Control)
- IN4 → GPIO 32 (Door Lock)

LED Strip:
- Connect through relay module for switching
- Ensure proper voltage rating

Servo Motor:
- VCC → 5V
- GND → GND
- Signal → GPIO 18

Buzzer:
- Positive → GPIO 19
- Negative → GND

Phase 2: Software Development

Step 1: Arduino IDE Setup

Step 2: Required Libraries

Step 3: Main Code Structure

cpp

#include <WiFi.h>
#include <WebServer.h>
#include <DHT.h>
#include <Servo.h>
#include <ArduinoJson.h>

// Network credentials
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

// Pin definitions
#define PIR_PIN 13
#define DHT_PIN 14
#define LDR_PIN 35
#define RELAY1_PIN 25  // Light
#define RELAY2_PIN 26  // Fan
#define RELAY3_PIN 27  // Heater
#define RELAY4_PIN 32  // Door Lock
#define SERVO_PIN 18
#define BUZZER_PIN 19

// Initialize components
DHT dht(DHT_PIN, DHT22);
Servo doorServo;
WebServer server(80);

// Global variables
bool lightState = false;
bool fanState = false;
bool heaterState = false;
bool doorLocked = true;
bool motionDetected = false;
float temperature = 0;
float humidity = 0;
int lightLevel = 0;

void setup() {
  Serial.begin(115200);
  
  // Initialize pins
  pinMode(PIR_PIN, INPUT);
  pinMode(LDR_PIN, INPUT);
  pinMode(RELAY1_PIN, OUTPUT);
  pinMode(RELAY2_PIN, OUTPUT);
  pinMode(RELAY3_PIN, OUTPUT);
  pinMode(RELAY4_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  
  // Initialize components
  dht.begin();
  doorServo.attach(SERVO_PIN);
  
  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  
  Serial.println("WiFi connected!");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
  
  // Setup web server routes
  setupServerRoutes();
  server.begin();
}

void loop() {
  server.handleClient();
  
  // Read sensors
  readSensors();
  
  // Check for motion
  checkMotion();
  
  // Automatic light control based on ambient light
  autoLightControl();
  
  delay(1000);
}

void readSensors() {
  temperature = dht.readTemperature();
  humidity = dht.readHumidity();
  lightLevel = analogRead(LDR_PIN);
  motionDetected = digitalRead(PIR_PIN);
}

void checkMotion() {
  if (motionDetected) {
    Serial.println("Motion detected!");
    // Trigger security alert
    securityAlert();
  }
}

void autoLightControl() {
  if (lightLevel < 500 && !lightState) {
    // Turn on light automatically in dark conditions
    digitalWrite(RELAY1_PIN, HIGH);
    lightState = true;
  }
}

void securityAlert() {
  // Sound buzzer
  digitalWrite(BUZZER_PIN, HIGH);
  delay(1000);
  digitalWrite(BUZZER_PIN, LOW);
  
  // Send notification (implement mobile app notification)
  sendNotification("Motion detected in your home!");
}

void setupServerRoutes() {
  // Main dashboard
  server.on("/", handleRoot);
  
  // API endpoints
  server.on("/api/status", handleStatus);
  server.on("/api/control", handleControl);
  server.on("/api/sensors", handleSensors);
}

void handleRoot() {
  String html = generateDashboard();
  server.send(200, "text/html", html);
}

void handleStatus() {
  StaticJsonDocument<200> doc;
  doc["light"] = lightState;
  doc["fan"] = fanState;
  doc["heater"] = heaterState;
  doc["door"] = doorLocked;
  doc["motion"] = motionDetected;
  
  String response;
  serializeJson(doc, response);
  server.send(200, "application/json", response);
}

void handleControl() {
  if (server.hasArg("device") && server.hasArg("state")) {
    String device = server.arg("device");
    bool state = server.arg("state") == "true";
    
    if (device == "light") {
      digitalWrite(RELAY1_PIN, state ? HIGH : LOW);
      lightState = state;
    } else if (device == "fan") {
      digitalWrite(RELAY2_PIN, state ? HIGH : LOW);
      fanState = state;
    } else if (device == "heater") {
      digitalWrite(RELAY3_PIN, state ? HIGH : LOW);
      heaterState = state;
    } else if (device == "door") {
      doorServo.write(state ? 0 : 90);
      doorLocked = state;
    }
    
    server.send(200, "text/plain", "OK");
  } else {
    server.send(400, "text/plain", "Missing parameters");
  }
}

void handleSensors() {
  StaticJsonDocument<200> doc;
  doc["temperature"] = temperature;
  doc["humidity"] = humidity;
  doc["light_level"] = lightLevel;
  doc["motion"] = motionDetected;
  
  String response;
  serializeJson(doc, response);
  server.send(200, "application/json", response);
}

String generateDashboard() {
  String html = R"(
<!DOCTYPE html>
<html>
<head>
    <title>Smart Home Dashboard</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        body { font-family: Arial, sans-serif; margin: 20px; background: #f0f0f0; }
        .container { max-width: 800px; margin: 0 auto; }
        .card { background: white; padding: 20px; margin: 10px 0; border-radius: 10px; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
        .sensor-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 15px; }
        .control-btn { padding: 10px 20px; margin: 5px; border: none; border-radius: 5px; cursor: pointer; }
        .on { background: #4CAF50; color: white; }
        .off { background: #f44336; color: white; }
        .sensor-value { font-size: 24px; font-weight: bold; color: #333; }
        .sensor-label { color: #666; margin-bottom: 5px; }
        h1 { color: #333; text-align: center; }
        h2 { color: #555; border-bottom: 2px solid #ddd; padding-bottom: 10px; }
    </style>
</head>
<body>
    <div class="container">
        <h1>🏠 Smart Home Dashboard</h1>
        
        <div class="card">
            <h2>📊 Sensor Readings</h2>
            <div class="sensor-grid">
                <div>
                    <div class="sensor-label">Temperature</div>
                    <div class="sensor-value" id="temp">--°C</div>
                </div>
                <div>
                    <div class="sensor-label">Humidity</div>
                    <div class="sensor-value" id="humidity">--%</div>
                </div>
                <div>
                    <div class="sensor-label">Light Level</div>
                    <div class="sensor-value" id="light">--</div>
                </div>
                <div>
                    <div class="sensor-label">Motion</div>
                    <div class="sensor-value" id="motion">--</div>
                </div>
            </div>
        </div>
        
        <div class="card">
            <h2>🎛️ Device Control</h2>
            <button class="control-btn" id="lightBtn" onclick="toggleDevice('light')">💡 Light</button>
            <button class="control-btn" id="fanBtn" onclick="toggleDevice('fan')">🌀 Fan</button>
            <button class="control-btn" id="heaterBtn" onclick="toggleDevice('heater')">🔥 Heater</button>
            <button class="control-btn" id="doorBtn" onclick="toggleDevice('door')">🚪 Door Lock</button>
        </div>
    </div>

    <script>
        function updateSensors() {
            fetch('/api/sensors')
                .then(response => response.json())
                .then(data => {
                    document.getElementById('temp').textContent = data.temperature + '°C';
                    document.getElementById('humidity').textContent = data.humidity + '%';
                    document.getElementById('light').textContent = data.light_level;
                    document.getElementById('motion').textContent = data.motion ? 'Detected' : 'None';
                });
        }

        function updateStatus() {
            fetch('/api/status')
                .then(response => response.json())
                .then(data => {
                    updateButtonState('lightBtn', data.light);
                    updateButtonState('fanBtn', data.fan);
                    updateButtonState('heaterBtn', data.heater);
                    updateButtonState('doorBtn', data.door);
                });
        }

        function updateButtonState(btnId, state) {
            const btn = document.getElementById(btnId);
            btn.className = 'control-btn ' + (state ? 'on' : 'off');
        }

        function toggleDevice(device) {
            fetch('/api/status')
                .then(response => response.json())
                .then(data => {
                    const currentState = data[device];
                    const newState = !currentState;
                    
                    fetch(`/api/control?device=${device}&state=${newState}`)
                        .then(() => updateStatus());
                });
        }

        // Update data every 2 seconds
        setInterval(() => {
            updateSensors();
            updateStatus();
        }, 2000);

        // Initial load
        updateSensors();
        updateStatus();
    </script>
</body>
</html>
)";
  return html;
}

void sendNotification(String message) {
  // Implement notification system
  // Can use Firebase, Pushover, or custom notification service
  Serial.println("Notification: " + message);
}

Phase 3: Mobile App Development

Option 1: Blynk App (Recommended for beginners)

Option 2: MIT App Inventor

Option 3: Flutter/React Native (Advanced)

Phase 4: Testing and Deployment

Testing Checklist

Deployment Steps

Software Requirements

Development Environment

Libraries Required

WiFi - Built-in
WebServer - Built-in
DHT sensor library - by Adafruit
Servo - Built-in
ArduinoJson - by Benoit Blanchon
PubSubClient - by Nick O'Leary
Blynk - by Blynk

Mobile App Options

Circuit Diagram

ESP32 Pin Connections:
=====================
GPIO 13 ← PIR Motion Sensor (OUT)
GPIO 14 ← DHT22 Temperature Sensor (DATA)
GPIO 35 ← LDR Light Sensor (analog)
GPIO 25 → Relay 1 (Light Control)
GPIO 26 → Relay 2 (Fan Control)
GPIO 27 → Relay 3 (Heater Control)
GPIO 32 → Relay 4 (Door Lock)
GPIO 18 → Servo Motor (Signal)
GPIO 19 → Buzzer (Positive)

Power Connections:
=================
3.3V → PIR VCC, DHT22 VCC, LDR (one end)
5V → Relay VCC, Servo VCC
GND → All component grounds

Mobile App Control Features

Core Features

App Development Platforms

Blynk (Recommended for Students)

MIT App Inventor

Flutter

Reference Resources

Online Tutorials

YouTube Channels

Sri Lankan Suppliers

Books and Documentation

Project Timeline

Week 1: Planning and Component Procurement

Week 2: Basic Hardware Setup

Week 3: Software Development

Week 4: Advanced Features

Week 5: Testing and Documentation

Troubleshooting Guide

Common Issues and Solutions

Safety Precautions

Future Enhancements

Possible Upgrades

Scalability Options

Conclusion

This smart home automation prototype provides a comprehensive foundation for understanding IoT concepts, embedded programming, and mobile app development. The project is designed to be educational while producing a functional system that can be extended and improved.

The estimated budget of LKR 7,830 - 12,900 makes this project accessible to students while providing hands-on experience with real-world technologies. The modular design allows for incremental development and testing.

This project serves as an excellent foundation for understanding modern IoT systems and can be expanded into more complex automation solutions.

Document Version: 1.0
Last Updated: July 2025
Target Audience: Engineering Students, Sri Lanka

Smart Home Automation Prototype - Complete Student Guide

Project Overview