Schematic Star

How to Build a Low-Cost Electronic Weather Station with Arduino

Introduction

As an electronics hobbyist looking to get more experience with microcontroller programming and circuit design, I decided to take on the challenge of building my own electronic weather station using an Arduino board. A weather station allows you to measure and record various environmental parameters like temperature, humidity, rainfall, wind speed and direction right from your own backyard. While professional grade weather stations can cost hundreds or even thousands of dollars, it is possible to build a functional and accurate weather station on a budget using an Arduino and some basic components.

In this comprehensive guide, I will walk through the entire process of constructing a low-cost Arduino weather station from start to finish. I will cover the components needed, how to assemble the circuit, write the code to take sensor readings, display and store the data, and finally how to install the weather station for outdoor operation. With the help of this guide, you will gain valuable skills in electronics, programming, and working with environmental sensors while ending up with your own fully-functional weather monitoring system.

Required Components

Building the weather station will require the following main components:

This list covers the essential sensors and components required for a functional weather station. The total cost depends on options chosen but can easily be kept under $100, especially if salvaging some components.

Circuit Assembly

With the components acquired, it's time to start building the circuit on the breadboard. The first step is connecting the Arduino Uno to the breadboard power supply to provide the regulated 5V power source for the components. This involves connecting the 5V and GND pins from the Arduino to the positive and negative power rails that run along the sides of the breadboard.

Next, the real time clock (RTC) module should be connected. This involve four connections:

The DHT11 temperature and humidity sensor is connected similarly using four jumper wires:

The rain gauge and anemometer are analog sensors so they will interface with the Arduino's analog input pins. For example, connect:

The wind direction sensor can be digital (hall effect or resistive) so it would connect through a digital pin like Arduino pin 2.

Finally, the LCD display requires 6 connections:

Once all the components are connected to the Arduino, the full circuit can be reviewed and tested to verify operation before moving to the coding and construction phases.

Writing the Arduino Sketch

With the electronic hardware built, the next phase is writing the Arduino sketch that will collect data from the sensors, process and display it, and log it to the SD card.

The first step is including the required libraries for the real time clock, SD card, LCD display, and DHT sensor:

```c

include

include

include

include

include

include

```

In the setup() function, we initialize the connected hardware components:

```c
void setup() {

Wire.begin();
rtc.begin();

lcd.begin(16, 2);

sd.begin(chipSelect);

dht.setup(dhtPin);

// additional setup
}
```

The main program logic goes in the loop() function which runs continuously. Here we will read the sensor data, print it to the LCD, save to SD card, and delay for an interval before repeating:

```c
void loop() {

// Read humidity
float humidity = dht.getHumidity();

// Read temperature
float temperature = dht.getTemperature();

// Read rain gauge
float rain = analogRead(rainPin);

// Read wind speed
float windSpeed = analogRead(windPin);

// Read wind direction
int windDirection = digitalRead(windDirPin);

// Timestamp
DateTime now = rtc.now();

// Print readings to LCD

// Log readings to SD card

// Delay before next reading

delay(10000);

}
```

The sketch can be further expanded to calculate derived values like wind chill, dew point, daily rain totals, wind direction names, etc. Useful debugging statements can be added during initial testing.

With the Arduino sketch written, the code can be uploaded to the board to bring the weather station to life!

Construction and Installation

With the electronics and software complete, the weather station needs to be made rugged to withstand long-term outdoor operation.

For the enclosure, a weatherproof plastic box is ideal. It should allow access to mount the solar radiation shield for the temperature sensor, funnels to channel rain into the gauge, and wiring for external sensors. Desiccant packs can be added to prevent internal moisture build up.

The Arduino board and breadboard circuit should be secured inside, either by mounting on a piece of perfboard or using adhesive. Wiring to the external sensors should be made with twisted pair cable and waterproof connections. Avoid long runs if possible.

Finally, for installation, the enclosure should be securely mounted in an open area away from obstructions that could influence wind and rain measurements. The solar radiation shield gives the most accurate temperature data when hung at 5 feet elevation in an open space. All external sensors should be securely mounted but easily accessible for periodic cleaning and maintenance.

With proper construction and installation, the weather station will deliver reliable meteorological data to track local weather and climate trends. Periodic maintenance like cleaning debris from the rain gauge filter will keep measurements accurate.

Conclusion

Building your own weather station using an Arduino is a highly educational and rewarding electronics project, allowing you to obtain useful weather data while gaining valuable experience working with microcontroller programming and interfacing with electronic sensors.

This guide provided step-by-step instructions on selecting components, assembling the circuit, writing the Arduino code, constructing the enclosure, and proper installation techniques. With all the steps completed, you now have your own low-cost but highly functional electronic weather monitoring system!

The capabilities of the weather station can be expanded over time by adding additional sensors like solar radiation, lightning detection, soil moisture probes, and integrating the data into cloud-based databases for automated weather recording. The Arduino platform provides a solid foundation to create a truly customized and professional environmental monitoring solution.