IoT Weather Monitoring Station

Real-time environmental monitoring built on a Raspberry Pi. On-board sensors stream temperature, humidity, and air quality (PM2.5) to a live web dashboard over MQTT, with Node-RED handling flow logic and alerting.

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Live Demo

View the live dashboard — runs on real Auckland weather data by default (Open-Meteo API), no hardware required.

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Architecture

  Sensors            Edge Device           Broker          Logic            Frontend
┌──────────┐       ┌─────────────┐       ┌────────┐     ┌──────────┐     ┌────────────┐
│ DHT22    │──────▶│             │       │        │     │          │     │            │
│ (temp/RH)│       │ Raspberry   │──────▶│  MQTT  │────▶│ Node-RED │────▶│  Dashboard │
│ PMS5003  │──────▶│ Pi          │ JSON  │ broker │ sub │  flows   │ ws  │ (HTML/JS)  │
│ (PM2.5)  │       │ publisher.py│       │        │     │ + alerts │     │  live UI   │
└──────────┘       └─────────────┘       └────────┘     └──────────┘     └────────────┘

Data Sources

The dashboard supports three modes, selectable via a dropdown:

Mode	Description
Auckland (live)	Real temperature, humidity and PM2.5 from the free Open-Meteo API. Backfills 48 hours of real hourly data.
Simulated	Realistic in-browser random-walk data. No backend required.
Live MQTT	Connects to your MQTT broker over WebSocket and renders real Raspberry Pi sensor data.

Hardware

Component	Part	Connection
Compute	Raspberry Pi 4	—
Temp / Humidity	DHT22 / AM2302	GPIO4 (1-wire data)
Air quality	PMS5003	UART (/dev/serial0)

No hardware? Every script includes a --simulate flag that produces realistic drifting values so you can run the full pipeline on any machine.

Quick Start

1. Broker

docker run -it -p 1883:1883 -p 9001:9001 eclipse-mosquitto

2. Publisher

cd firmware
pip install -r requirements.txt
cp config.example.json config.json

python sensor_publisher.py              # real sensors
python sensor_publisher.py --simulate   # no hardware

3. Node-RED — import node-red/flow.json via Menu → Import, then deploy.

4. Dashboard — open dashboard/index.html in a browser.

MQTT Payload

Published to amir/iot/weather (configurable):

{
  "temperature": 26.4,
  "humidity": 61.2,
  "pm25": 18.0,
  "ts": 1718900000
}

Repository Structure

iot-weather-station/
├── firmware/
│   ├── sensor_publisher.py     # reads sensors, publishes to MQTT
│   ├── requirements.txt
│   └── config.example.json
├── node-red/
│   └── flow.json               # importable Node-RED flow
├── dashboard/
│   ├── index.html              # live web dashboard
│   ├── styles.css
│   └── app.js
└── preview.png

License

MIT — see LICENSE.