How to Build a DIY IoT Weather Station with an ESP8266 and Arduino

Building your own IoT weather station with an ESP8266 and Arduino is a fun electronics project that allows you to get hands-on experience with IoT and microcontroller programming. Here is a step-by-step guide on how I built my own and got it working.

Gather the Required Components

To build the weather station, you will need the following main components:

• Arduino Uno - The brain of the weather station. I used an Arduino Uno but any Arduino board will work.

• ESP8266 WiFi Module - Allows the Arduino to connect to the internet to send sensor data. I used a NodeMCU module.

• DHT11/DHT22 Temperature and Humidity Sensor - Measures ambient temperature and humidity. The DHT22 gives higher accuracy readings.

• Rain Sensor - Detects rainfall and measures precipitation.

• Anemometer - Measures wind speed by counting rotations of a spinning cup.

• Weatherproof Enclosure - Houses the electronics. An IP65 rated enclosure is ideal.

Optional components:

• BMP180 Barometric Pressure Sensor - Measures atmospheric pressure.

• Photoresistor - To detect light/brightness levels.

• Real Time Clock module - For logging time stamped readings.

For power, I used a 5V USB phone charger along with a power bank to make the station portable.

Assemble the Circuit

Here are the steps I followed to assemble the circuit on a breadboard:

1. Connect the Arduino's 5V and GND pins to power the components.

2. Connect the digital output of the rain sensor to a digital pin on the Arduino.

3. Connect the DHT22 sensor's data pin to a digital pin per its requirements.

4. Connect the SDA/SCL pins of the BMP180 to the Arduino's I2C pins.

5. Connect the photoresistor and anode resistor to an analog input pin.

6. Connect the ESP8266's CH_PD and RST pins to enable communication.

7. Connect the TX/RX pins between the ESP8266 and Arduino for software serial.

Install Required Libraries

The Arduino will need the following libraries installed to compile the code:

• DHT Sensor Library
• Adafruit BMP085 Library
• ESP8266WiFi Library

Install these through the Arduino IDE's Library Manager.

Write the Arduino Sketch

The Arduino sketch has the following key functions:

• Initialize the sensors and WiFi module.

• In void loop():

  • Read values from the various sensors.

  • Connect to WiFi network.

  • Format sensor data as a JSON string.

  • Send data as an HTTP POST request to the API endpoint.

• Include error handling routines.

Create a Backend to Receive the Data

To store and display the weather data sent by the Arduino, you need a backend service with a REST API.

Popular options include:

• MQTT Broker - Lightweight broker to publish/subscribe to messages.

• Web Server - Host a web app to receive and display data.

• Cloud Platforms - AWS, GCP provide services to stream, store, and visualize data.

For my project, I used Node-RED to create a simple MQTT broker and dashboard to display the received data.

Power and Enclose the Project

With the circuit complete and code working, the final steps are:

• Enclose the project in a weatherproof enclosure or container.

• Provide stable 5V power from a USB charger, power bank or solar panel setup.

• Optionally, add a backup battery like a power bank to keep it running during power outages.

• Mount the rain sensor and anemometer outside with the enclosure in a suitable location.

And that's it! With all the steps complete, you now have your own fully functional IoT weather station! Feel free to customize it by adding more sensors and capabilities.