How to Build a Low Cost Electronic Weather Station with Arduino

Building your own electronic weather station with Arduino is a fun and educational project that allows you to measure temperature, humidity, barometric pressure, wind speed, and more right from your own backyard. With just a few components, you can start collecting all kinds of useful weather data. Here's a step-by-step guide on how I built my own low cost Arduino weather station.

Gathering the Required Components

The first step is acquiring all the parts you'll need. Here are the main components I used for my project:

Arduino Uno board - The brains of the weather station. An inexpensive Arduino board like the Uno works great.
Breadboard - Allows for easily connecting wires and components.
DHT22 temperature and humidity sensor - For measuring ambient temperature and humidity. More accurate than the DHT11.
Barometric pressure sensor - I used the BMP180 model to get atmospheric pressure data.
Anemometer - Measures wind speed by detecting rotations. Must be properly calibrated.
Rain gauge - Tips and empties a vessel to quantify rainfall.
Real time clock module - Keeps accurate time for data logging.
Micro SD card module - Logs all sensor data to a removable memory card.
Breadboard wires - For connections. Jumper wires work well.
LCD display - Shows the current sensor readings. A 16x2 LCD is common.
Resistors - Help regulate voltage/current. 10k and 220 ohm resistors are needed.

This list covers the major components I used. Other optional parts like solar panels, anemometer rotors, housing, cables, etc may be needed depending on your exact setup.

Assembling the Circuit

With all my parts gathered, it's time to assemble the circuit. This involves properly connecting all the components to the Arduino board. Using a breadboard makes circuit assembly much easier. Refer to a schematic diagram and have the Arduino pinouts handy. Here are the basic steps I followed:

Mount the Arduino and breadboard on a base plate and connect them together with jumper wires.
Add the DHT22 sensor, connecting the power, ground, and data pins to the proper Arduino pins via the breadboard.
Similarly, connect the barometric pressure sensor. These modules only use a few pins.
Connect the RTC module following the pinout. Pay close attention to the voltage requirements.
Add the SD card module using SPI or UART communication. SD cards use SPI which requires 4 pins.
Connect the LCD panel to the appropriate digital and analog pins. Use a potentiometer to control the contrast.
The anemometer and rain gauge have less exact connections. Just provide power and connect any digital pin to sense the signal.
Use resistors as needed to avoid damage from shorts and overcurrent. The DHT22 has an onboard resistor.

Double check all wiring before powering everything on!

Writing the Arduino Sketch

Now it's time to program the Arduino to actually read the sensors and save data. This involves writing a sketch in the Arduino IDE software.

The sketch will need to include libraries for the various hardware components like the DHT22 and SD card. These add functionality.

In the setup() function:

Initialize the serial connection for debugging.
Initialize each component by calling the appropriate library functions.
Set pinmodes.
Begin the SD card and LCD screen.

In the loop():

Read values from each sensor using the corresponding library functions.
Print the readings to the LCD display.
Construct data strings for the SD card with timestamp and units.
Write the data strings to the card using sd.println().
Add brief delays to avoid reading sensors too quickly.

The [RTC module] will allow time stamping all the data entries. Writing to the SD card from the loop() allows continuous data logging as long as the Arduino has power.

Taking Measurements

Once the sketch is uploaded, the weather station will spring to life! It can simply be left running to automatically record ambient conditions over time. The LCD provides live readouts for quick glances at current weather. But the true value lies in the timestamped sensor data logged to the SD card.

The card can be removed and plugged into a computer; all data can then be imported into a spreadsheet for analysis and graphing. Having properly logged datasets is the key to maximizing a weather station's usefulness.

And there you have it! With the right parts and some coding knowledge, you can build your own capable Arduino weather station. Not only is it satisfying to see your creation come together, but it also provides great hands-on learning about electronics, sensors and measurement principles.