Smart Home Security System

ESP32 · Blynk IoT · Multi-Sensor Monitoring

A real-time IoT security solution that monitors environmental hazards and intrusion events, delivers instant alerts via Blynk, and autonomously triggers safety responses — all from a single ESP32 microcontroller.

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Table of Contents

• Overview
• Features
• Hardware Requirements
• Software Stack
• Circuit & Pin Configuration
• Blynk Dashboard Configuration
• System Logic
• Project Structure
• Getting Started
• Simulation
• Roadmap
• License

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Overview

The Smart Home Security System is an IoT-based embedded project that provides continuous, automated monitoring of a home environment. Built on the ESP32 microcontroller and integrated with the Blynk IoT platform, the system uses four sensors to detect temperature spikes, gas leakage, open flames, and unauthorized motion.

When a hazard is detected, the system reacts immediately — activating an alarm buzzer, switching a relay (to cut power or trigger an external device), updating LED status indicators, and pushing real-time notifications to the user's smartphone through Blynk Cloud.

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Features

• Real-time temperature and humidity monitoring
• LPG/smoke/methane gas leakage detection
• Open flame detection via infrared flame sensor
• Human motion detection using a PIR sensor
• Automated alarm (buzzer) and relay control on hazard detection
• Live sensor dashboard on Blynk IoT with gauges and status LEDs
• Instant push notifications for each alert type
• Event logging to Blynk Cloud

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Hardware Requirements

Component	Qty
ESP32 Development Board	1
DHT22 Temperature & Humidity Sensor	1
MQ2 Gas Sensor	1
PIR Motion Sensor	1
Flame Sensor	1
Relay Module	1
Buzzer	1
LED	1
220 Ω Resistor	1
10 kΩ Pull-up Resistor (for DHT22)	1
Breadboard	1
Jumper Wires	As required

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Software Stack

Tool / Platform	Purpose
Arduino IDE	Firmware development
ESP32 Board Package	ESP32 support for Arduino IDE
Blynk IoT Platform	Cloud dashboard & push notifications
Wokwi Simulator	Circuit simulation & testing
Git & GitHub	Version control
C / C++	Programming language

Required Arduino Libraries:

• Blynk — Blynk IoT connectivity
• DHTesp — DHT22 sensor support

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Circuit & Pin Configuration

Component	ESP32 GPIO
DHT22 Data	GPIO 27
PIR Motion Sensor	GPIO 15
Flame Sensor	GPIO 4
MQ2 Analog Output	GPIO 35
Relay Module	GPIO 2
Buzzer	GPIO 14

Note: GPIO 35 is input-only on ESP32 — suitable for the MQ2 analog output. Ensure a 10 kΩ pull-up resistor is connected on the DHT22 data line.

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Blynk Dashboard Configuration

Virtual Pin	Widget	Purpose
V0	Gauge	Temperature (°C)
V1	Gauge	Humidity (%)
V2	Gauge	Gas Level (raw ADC)
V3	LED	Motion Detection Status
V4	LED	Relay Status
V5	LED	Flame Detection Status

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System Logic

Normal State

All sensors read within safe thresholds. The buzzer and relay remain OFF. The dashboard reflects live sensor values.

Alert Thresholds

Condition	Threshold
Temperature	> 50 °C
Gas Level	> 3800 (ADC raw value)
Flame Detected	Sensor output LOW
Motion Detected	PIR output HIGH

Emergency Response (any threshold breached)

1. Buzzer activates immediately
2. Relay switches ON (can control external load or cut power)
3. Blynk dashboard LED indicators update
4. Push notification sent to user via Blynk app
5. Event logged to Blynk Cloud
6. System continues monitoring

Operational Flow

Read Sensors → Upload to Blynk Cloud → Update Dashboard
     ↓
Check Thresholds
     ↓
Hazard Detected? → YES → Activate Buzzer + Relay → Send Notification → Log Event
     ↓
    NO
     ↓
Continue Loop

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Project Structure

Smart-Home-Security-System/
│
├── sketch.ino          # Main Arduino firmware
├── diagram.json        # Wokwi circuit diagram
├── libraries.txt       # Required library list
├── README.md
│
└── assets/
    ├── circuit-diagram.png
    ├── dashboard.png
    └── simulation.png

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Getting Started

1. Clone the Repository

git clone https://github.com/Sanjaykumar9441/Smart-Home-Security-System.git
cd Smart-Home-Security-System

2. Install Arduino Libraries

In Arduino IDE, go to Sketch → Include Library → Manage Libraries and install:

• Blynk
• DHTesp

3. Configure Blynk Credentials

Open sketch.ino and update the following with your Blynk project credentials:

#define BLYNK_TEMPLATE_ID   "your_template_id"
#define BLYNK_TEMPLATE_NAME "your_template_name"
#define BLYNK_AUTH_TOKEN    "your_auth_token"

Also update your Wi-Fi credentials:

char ssid[] = "your_wifi_ssid";
char pass[] = "your_wifi_password";

4. Flash the ESP32

• Connect the ESP32 to your PC via USB.
• Select the correct Board and Port in Arduino IDE.
• Click Upload.
• Open Serial Monitor (115200 baud) to verify the connection and sensor output.

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Simulation

This project can be tested fully in the browser using Wokwi — no hardware required.

🔗 Open in Wokwi Simulator

In the simulator, you can:

• Observe live sensor readings
• Trigger fire, gas leak, and motion conditions interactively
• Verify buzzer and relay responses
• Confirm Blynk dashboard updates in real time

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Roadmap

Planned enhancements for future versions:

• GSM-based SMS alert system
• IP camera surveillance integration
• AI-powered anomaly and threat detection
• Firebase Cloud Storage for event history
• Email notification support
• Voice assistant integration (Alexa / Google Home)
• Dedicated mobile application

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Developer

Chitturi Sanjay Kumar
Electronics & Communication Engineering Aditya University, Surampalem GitHub: github.com/Sanjaykumar9441

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License

This project is open-source and available for educational and research purposes. You are free to use, modify, and distribute it with attribution.