SmartFusion: Multi-Sensor Data Fusion and Environmental Monitoring

SmartFusion is an intelligent IoT-based air quality monitoring system that leverages Multi-Level Data Fusion to provide accurate CO gas concentration and environmental risk assessments.
The system integrates hardware edge nodes with a Python-based intelligent gateway and cloud-hosted databases.

Features

• Multi-Level Fusion
  • Kalman Filtering (Data-level)
  • Dempster-Shafer Theory (Decision-level)
• Dual Protocol Support
  • HTTP (REST -- Legacy)
  • MQTT (Publish/Subscribe -- Optimized)
• Fault Tolerance
  • Local buffering for offline data persistence
• Real-time Analytics
  • Performance metrics: SNR, RMSE, VUR
• Cloud Integration
  • MongoDB Atlas
  • Adafruit IO

Hardware Components

The system utilizes the following hardware at the Edge layer:

• NodeMCU (ESP8266) -- Main processing unit and WiFi gateway\
• MQ-7 Gas Sensor -- Carbon Monoxide (CO) detection\
• DHT11 Sensor -- Temperature and Humidity monitoring\
• Level Shifters / Potentiometers -- Sensor calibration and voltage matching

Software Stack and Platforms

Development Environments

• Arduino IDE -- Programming and flashing NodeMCU firmware\
• VS Code / PyCharm -- Python Gateway and data analysis scripts

Cloud Platforms

• MongoDB Atlas -- Cloud-hosted NoSQL database\
• Adafruit IO -- Real-time IoT dashboard and monitoring\
• HiveMQ -- Public MQTT broker

Software Libraries

Python - paho-mqtt (v2.1.0) - pymongo - matplotlib - numpy - Adafruit_IO

Arduino - ESP8266WiFi - PubSubClient - DHT Sensor Library

Communication Protocols

1. HTTP Protocol (Legacy)

• Architecture: Client--Server (Request--Response)
• Workflow: NodeMCU sends JSON payloads via POST requests to a Flask-based Python server
• Best for: Simple point-to-point communication

2. MQTT Protocol (Current / Optimized)

• Architecture: Publish/Subscribe
• Broker: broker.hivemq.com
• Workflow: Decouples sensor nodes from the gateway, enabling lower latency and higher reliability

Edge Node Implementation

The NodeMCU firmware (AQI.ino) is responsible for:

• Initializing WiFi and MQTT connections
• Sampling data from MQ-7 (Analog) and DHT11 (Digital) sensors
• Packaging sensor data into JSON format
• Publishing data to the smart_fusion/sensors topic every 5 seconds

Performance Metrics

Metric	Value (Avg)	Description
SNR	> 25 dB	Signal-to-Noise Ratio
RMSE	< 0.05	Root Mean Square Error
VUR	~ 85%	Variance Reduction

Installation and Setup

1. Clone the repository

git clone https://github.com/yourusername/SmartFusion.git

2. Install dependencies

pip install paho-mqtt pymongo matplotlib numpy Adafruit_IO

3. Configure Database

• Update MONGO_URI in main_gateway.py

4. Run the Gateway

python main_gateway.py

5. Run the Visualizer

python output_analysis.py

Author

Developed by Shady Nikooei as an Computer Engineer.