🌬️ Air Pollution Monitoring System

Real-time air quality monitoring with visual and audio alerts

An IoT-based air pollution monitoring system that provides real-time air quality measurements using the MQ135 sensor. The system displays AQI (Air Quality Index) values on an LCD screen and provides intuitive color-coded alerts to help users understand air quality conditions at a glance.

🚀 Features

• 📊 Real-time AQI monitoring using MQ135 air quality sensor
• 🖥️ LCD display showing current air quality readings
• 🚨 Multi-level alert system with color-coded LED indicators:
  • 🟢 Green LED → Good air quality (AQI: 0-50)
  • 🔵 Blue LED → Moderate air quality (AQI: 51-100)
  • 🔴 Red LED → Unhealthy air quality (AQI: 101+)
• 🔊 Audio alerts via buzzer for hazardous conditions
• 💻 Serial monitor output for debugging and data logging

🛠️ Hardware Components

Component	Quantity	Purpose
Arduino Uno	1	Main microcontroller
MQ135 Air Quality Sensor	1	Air quality measurement
16x2 LCD Display	1	Data visualization
LEDs (Green, Blue, Red)	3	Status indicators
Buzzer	1	Audio alerts
Resistors	3	LED current limiting
Breadboard	1	Circuit assembly
Jumper Wires	Multiple	Connections

📋 Pin Configuration

Arduino Connections

Component	Arduino Pin	Notes
MQ135 Sensor	A0	Analog input
LCD Display
├─ RS	2	Register select
├─ EN	3	Enable
├─ D4	4	Data bit 4
├─ D5	5	Data bit 5
├─ D6	6	Data bit 6
└─ D7	7	Data bit 7
Green LED	8	Good AQI indicator
Blue LED	9	Moderate AQI indicator
Red LED	10	Unhealthy AQI indicator
Buzzer	11	Audio alert

🔧 Circuit Diagram

Complete circuit schematic showing all component connections

🔨 Assembly Instructions

1. Sensor Connection

   • Connect MQ135 VCC to Arduino 5V
   • Connect MQ135 GND to Arduino GND
   • Connect MQ135 analog output to Arduino pin A0

2. LCD Setup

   • Wire LCD according to the pin configuration table above
   • Connect LCD VDD to 5V and VSS to GND
   • Connect V0 to a potentiometer for contrast adjustment

3. LED Indicators

   • Connect each LED's anode to its respective digital pin through a 220Ω resistor
   • Connect all LED cathodes to GND

4. Buzzer Connection

   • Connect buzzer positive to pin 11
   • Connect buzzer negative to GND

5. Power Connections

   • Ensure all components share common ground
   • Verify 5V power distribution to all components

📊 AQI Classification

AQI Range	Air Quality Level	LED Indicator	Buzzer
0-50	Good	🟢 Green	Off
51-100	Moderate	🔵 Blue	Off
101-150	Unhealthy for Sensitive Groups	🔴 Red	Off
151-200	Unhealthy	🔴 Red	On
201-300	Very Unhealthy	🔴 Red	On
301+	Hazardous	🔴 Red	On

🖥️ System Output

Real-time AQI display on LCD screen

Serial Monitor Output Example

🌬️ Air Quality Monitoring System Started
======================================
Air Quality: 45 PPM
Status: Good ✅
AQI Level: Green

Air Quality: 78 PPM  
Status: Moderate ⚠️
AQI Level: Blue

Air Quality: 150 PPM
Status: Unhealthy 🚨
AQI Level: Red
Alert: Buzzer Activated

🚀 Getting Started

Prerequisites

• Arduino IDE installed on your computer
• Basic knowledge of Arduino programming
• Required libraries: LiquidCrystal.h (included in Arduino IDE)

Installation Steps

1. Clone the repository

   git clone https://github.com/AadityaPanda/Air-Pollution-Monitoring-System.git
   cd Air-Pollution-Monitoring-System

2. Open Arduino IDE

   • Load the air_pollution_monitor.ino file
   • Select your Arduino board and COM port

3. Upload the code

   • Verify the code compiles without errors
   • Upload to your Arduino board

4. Monitor the system

   • Open Serial Monitor (115200 baud rate)
   • Observe real-time AQI readings and system status

🔧 Calibration

The MQ135 sensor requires a warm-up period of 24-48 hours for accurate readings. For precise measurements:

1. Allow the sensor to stabilize in clean air
2. Adjust the calibration values in the code if necessary
3. Compare readings with a reference air quality meter

🎯 Applications

• Home Monitoring: Track indoor air quality
• Office Environments: Monitor workplace air conditions
• Educational Projects: Learn about IoT and environmental monitoring
• Health Awareness: Alert users to poor air quality conditions

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Arduino community for extensive documentation
• MQ135 sensor manufacturers for technical specifications
• Contributors and testers who helped improve this project

📞 Support

If you encounter any issues or have questions:

• 📧 Email: aadityapanda23@gmai.com
• 💬 Issues: Create an issue
• 📚 Documentation: Project Wiki

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Made with ❤️ for cleaner air and better health