IoT-Based Weather Monitoring System

Real-time IoT weather monitoring system using ESP32, DHT22 sensor, MQTT protocol, and Raspberry Pi with Node-RED dashboard and multi-channel notifications.

Features

• Real-time temperature and humidity monitoring
• MQTT wireless communication protocol
• Email and Telegram notifications
• Web-based dashboard with Node-RED
• Automated threshold alerts

Technologies Used

• ESP32 microcontroller
• DHT22 temperature/humidity sensor
• MQTT protocol
• Raspberry Pi 4
• Node-RED
• JavaScript

System Architecture

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│   ESP32 + DHT22 │────│  MQTT Protocol   │────│  Raspberry Pi 4 │
│   (Publisher)   │    │  (Wireless)      │    │  (MQTT Broker)  │
└─────────────────┘    └──────────────────┘    └─────────────────┘
                                                         │
                                                         │
                                               ┌─────────────────┐
                                               │    Node-RED     │
                                               │ (Data Processing│
                                               │ & Automation)   │
                                               └─────────────────┘
                                                         │
                                        ┌────────────────┼────────────────┐
                                        │                │                │
                                ┌────────────────┐   ┌──────────────┐ ┌────────────────┐
                                │  Web Dashboard │   │ Email Alerts │ │ Telegram Bot   │
                                │   (Real-time)  │   │ (Gmail SMTP) │ │ (Notifications)│
                                └────────────────┘   └──────────────┘ └────────────────┘

Component Details

Hardware Layer:

• ESP32 Microcontroller: Handles sensor data collection and wireless communication
• DHT22 Sensor: Measures temperature and humidity with high accuracy
• Power Supply: 5V USB or battery powered for portable operation

Communication Layer:

• MQTT Protocol: Lightweight messaging protocol for IoT communication
• Wi-Fi Connection: Supports both standard networks and WPA2-Enterprise (eduroam)
• Topic Structure: sensor/dht22 for centralized data transmission

Processing Layer:

• Raspberry Pi 4: Central hub running Mosquitto MQTT broker
• Node-RED: Visual programming tool for data flow and automation
• Real-time Processing: 5-second data sampling with threshold monitoring

Application Layer:

• Web Dashboard: Real-time visualization with gauges and charts
• Email Notifications: Automated alerts via Gmail SMTP
• Telegram Integration: Bot commands and instant notifications

Installation

Prerequisites

• Raspberry Pi 4 with Raspbian OS
• ESP32 development board
• DHT22 temperature/humidity sensor
• Jumper wires and breadboard
• Wi-Fi network access

Hardware Setup

1. ESP32 and DHT22 Connection:

   DHT22 VCC  → ESP32 3.3V
   DHT22 GND  → ESP32 GND
   DHT22 DATA → ESP32 GPIO4
   

2. Power the ESP32 via USB or external power supply

Software Installation

1. Raspberry Pi Setup

# Update system
sudo apt update && sudo apt upgrade -y

# Install Mosquitto MQTT Broker
sudo apt install mosquitto mosquitto-clients -y
sudo systemctl enable mosquitto
sudo systemctl start mosquitto

# Install Node.js and npm
curl -fsSL https://deb.nodesource.com/setup_16.x | sudo -E bash -
sudo apt install nodejs -y

# Install Node-RED
sudo npm install -g --unsafe-perm node-red
sudo systemctl enable nodered
sudo systemctl start nodered

# Install Node-RED dependencies
cd ~/.node-red
npm install node-red-contrib-telegrambot
npm install node-red-node-email
npm install node-red-dashboard

2. ESP32 Setup

# Install Arduino IDE or PlatformIO
# Add ESP32 board support in Arduino IDE:
# File → Preferences → Additional Board Manager URLs:
# https://dl.espressif.com/dl/package_esp32_index.json

# Install required libraries:
# - WiFi (built-in)
# - PubSubClient
# - DHT sensor library

3. Configuration

MQTT Broker Configuration:

# Edit Mosquitto config
sudo nano /etc/mosquitto/mosquitto.conf

# Add these lines:
listener 1883
allow_anonymous true
persistence true
persistence_location /var/lib/mosquitto/

ESP32 Configuration:

• Update Wi-Fi credentials in hardware/esp32_dht22_mqtt.ino
• Set MQTT broker IP address (Raspberry Pi IP)
• Configure sensor pin assignments

Node-RED Setup:

1. Access Node-RED at http://raspberry-pi-ip:1880
2. Import the flow from node-red/flows.json
3. Configure email credentials in email nodes
4. Set up Telegram bot token in Telegram nodes
5. Deploy the flow

Usage

1. Power on the system:

   • Start Raspberry Pi and ensure MQTT broker is running
   • Power ESP32 - it will automatically connect and start transmitting

2. Access Dashboard:

   • Open browser and go to http://raspberry-pi-ip:1880/ui
   • View real-time temperature and humidity data

3. Configure Alerts:

   • Modify temperature threshold in Node-RED function
   • Update email recipients and Telegram chat IDs
   • Customize notification intervals

4. Telegram Commands:

   • /status or /durum - Get current sensor readings
   • /help or /yardim - Show available commands

Project Structure

IoT-Based-Weather-Monitoring-System/
├── README.md
├── hardware/
│   └── esp32_dht22_mqtt.ino
├── node-red/
│   ├── flows.json
│   └── functions/
│       ├── nodeRED_data_seperator.js
│       ├── nodeRED_global_data_recorder.js
│       ├── nodeRED_telegram_command_processor.js
│       └── nodeRED_temperature_controller.js
├── documentation/
│   └── Final_Report.pdf
└── screenshots/
    ├── IoT-Based Weather Monitoring System Temperature and Humidity Dashboard Screenshot.jpeg
    ├── IoT-Based Weather Monitoring System Temperature and Humidity Email Notification Screenshot.jpeg
    └── IoT-Based Weather Monitoring System Temperature and Humidity Telegram Notification Screenshot.jpeg

Troubleshooting

Common Issues

ESP32 won't connect to Wi-Fi:

• Check credentials and network compatibility
• Ensure WPA2-Enterprise configuration is correct for eduroam

No data in dashboard:

• Verify MQTT broker is running: sudo systemctl status mosquitto
• Check ESP32 serial monitor for connection status
• Confirm Node-RED flow is deployed

Email notifications not working:

• Enable 2-factor authentication and app passwords in Gmail
• Check SMTP settings in Node-RED email node

Telegram bot not responding:

• Verify bot token is correct
• Ensure chat ID matches your Telegram account

Performance Optimization

• Power Management: Configure ESP32 deep sleep for battery operation
• Data Retention: Set up InfluxDB for historical data storage
• Scalability: Add multiple sensor nodes using unique MQTT topics
• Security: Implement MQTT authentication and SSL/TLS encryption

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/new-feature)
3. Commit your changes (git commit -am 'Add new feature')
4. Push to the branch (git push origin feature/new-feature)
5. Create a Pull Request

License

This project is open source and available under the MIT License.

Contact

• Author: Mehmet Oğuz Kocadere
• Email: canmehmetoguz@gmail.com
• GitHub: memo-13-byte
• LinkedIn: mehmet-oğuz-kocadere

Acknowledgments

• Hacettepe University Computer Engineering Department
• BBM460 Wireless and Mobile Networks Laboratory Course
• Node-RED Community for excellent documentation
• ESP32 and Arduino communities for hardware support