An IoT-based, community-driven air quality monitoring system designed to provide real-time AQI (Air Quality Index) estimation using multiple sensors. Built for both urban and rural coverage, this project empowers individuals to participate in environmental monitoring and decision-making.
This project presents a low-cost, scalable solution for air quality monitoring using IoT. It uses MQ-series gas sensors, particulate matter sensors, temperature & humidity sensors, and Bluetooth communication to calculate and visualize AQI in real-time.
What is AQI (Air Quality Index)? The Air Quality Index (AQI) is a standardized system used to measure and report the quality of air in a specific location. It tells you how clean or polluted the air is, and what associated health effects might be a concern for you.
- AQI ranges from 0 to 500.
- Lower AQI = cleaner air
- Higher AQI = more polluted air
| AQI Range | Air Quality | Health Impact |
|---|---|---|
| 0–50 | Good | Air quality is satisfactory |
| 51–100 | Moderate | Acceptable; some pollutants may affect very sensitive people |
| 101–150 | Unhealthy (Sensitive Groups) | May cause health effects for sensitive groups |
| 151–200 | Unhealthy | Everyone may begin to experience health effects |
| 201–300 | Very Unhealthy | Health warnings of emergency conditions |
| 301–500 | Hazardous | Health alert: everyone may be affected |
AQI is calculated based on concentrations of pollutants like:
- PM2.5, PM10
- CO (Carbon Monoxide)
- O₃ (Ozone)
- SO₂ (Sulfur Dioxide)
- NO₂ (Nitrogen Dioxide)
Crowd-sourcing is the practice of collecting data, services, or information by engaging a large number of people, especially from a community or public platform. In this project:
- Crowd-sourced AQI monitoring means many individuals place sensors in different locations (homes, streets, neighborhoods).
- These devices collect air quality data from multiple locations simultaneously.
- The data is combined to create a detailed and widespread pollution map, much more efficiently and cheaply than using a few government stations.
| Component | Functionality |
|---|---|
| Arduino UNO | Main microcontroller |
| MQ135 | CO₂, NH₃, benzene detection |
| MQ7 | Carbon Monoxide (CO) |
| MQ2 | Smoke, LPG, Methane |
| PMS5003 | PM2.5, PM10 detection |
| DHT11 / DHT22 | Temperature & Humidity |
| BME280 | Pressure, Temp, Humidity |
| HC-05 Bluetooth | Mobile communication |
| 16x2 LCD Display | Real-time local display |
My Crowd-Sourced AQI Monitoring System is designed using IoT architecture with low-cost, easily available hardware components. It consists of:
- Gas Sensors: MQ135, MQ7, MQ2 – detect CO₂, NH₃, CO, smoke, etc.
- Particulate Matter Sensor: PMS5003 – measures PM2.5 and PM10.
- Environmental Sensors: DHT11/DHT22 and BME280 – for temperature, humidity, and pressure.
- Arduino UNO: Reads data from all sensors and processes it.
- 16x2 LCD: Displays real-time values of gas concentrations, PM levels, temperature, humidity, and calculated AQI.
- HC-05 Bluetooth: Sends processed data to a mobile app for visualization and logging.
- Multiple such devices are deployed in various locations by different users (the crowd), forming a distributed monitoring network.
- Receives real-time AQI data via Bluetooth.
Each sensor continuously reads the concentration of gases (like CO, CO₂, NH₃), particulate matter (PM2.5, PM10), temperature, and humidity.
- Arduino processes the raw values.
- Using standard EPA formulas, it calculates the AQI for each pollutant.
- The maximum AQI among CO, PM2.5, PM10 is selected as the overall AQI.
- The AQI and sensor readings are shown on the LCD.
- The same data is sent to a connected mobile device via Bluetooth.
- When many users deploy this system in different areas, a network of real-time AQI monitors is created.
- This increases the spatial coverage and data accuracy of air quality reports.
The system's output was compared with official AQI data from the US Embassy in Islamabad and showed 99% accuracy.
| Pollutant | Concentration | AQI Value | AQI Category |
|---|---|---|---|
| PM2.5 | 162 µg/m³ | 212.5 | Very Unhealthy |
| PM10 | 170 µg/m³ | 108.4 | Unhealthy (Sensitive Groups) |
| CO | 0.32 ppm | 3.6 | Good |
| Overall AQI | — | 212.4 | Very Unhealthy |
Taken on 19th December, 2024 – 10:42 PM – Islamabad
| Parameter | Value | AQI Value | Health Impact |
|---|---|---|---|
| PM2.5 | 162 µg/m³ | 212.40 | Very Unhealthy |
| PM10 | 170 µg/m³ | 108.42 | Unhealthy (Sensitive) |
| CO | 0.32 ppm | 0 | Good |
- Our AQI: 212.40
- Accuracy: 99% vs US Embassy AQI System
- Awais Asghar
- Muhammad Hammad Sarwar
- Muhammad Ashar Javid
- School of Electrical Engineering & Computer Science (SEECS), NUST
