I like knowing what the temperature is in my back yard.
And the rainfall amount when it’s raining. And the wind speed and direction. That’s why I’ve had a weather station in my backyard for several years now.
We had two Accurite stations in two years. Both crapped out after a season.
So I set about building one that, should something go wrong, at least I could repair.
The end result cost less than the two Accurite stations combined. If I had done this first, I’d have saved money and had a much better weather station from the start.
- Powered from a reliable external source. AWG14 romex in conduit underground brings 12VDC to station.
- A relay in the power box allows for remote rebooting of the Pi. This is controlled by the PoolPi, which just happens to be nearby.
- Sparkfun sensor bundle. Wind speed / direction, tipping bucket rainfall gauge.
- BME280 temperature/humidity/pressure sensor mounted in protected chimney.
- PWM controlled variable speed fan pulls air up the chimney across the BME280 sensor, and also provides a ventilation flow for electronics.
- Pi accumulates data, formats it and then sends it once a minute to a mySQL database running on “Brilliant”, a little i3 Ubuntu machine in the house.
- Communication is over WiFi. Hardwire Ethernet proved to be too dangerous when lightning storms come around.
- Custom Python 3 runs the whole thing.
The nitty-gritty details are here on Github.
Here are some images to whet your appetite.
Inside the box.
The chimney directs airflow over the main sensor.
The Pi Camera 2 module is affixed to the front cover.
The hinge mount at the bottom of the pole allows WeatherPi to be lowered easily for maintenance.
The power box contains an old UPS circuit board, battery, a relay module, a 12vdc power supply and a 12V lightning arrestor.
WeatherPi outputs data to PWSweather.com.
It is true that this project is not for the faint-of-heart. It was a lot of work, but it was also a lot of fun.
And, in the end, it is very gratifying to know something I built from the ground up is doing as good a job as any commercial system out there.
And I learned a LOT in the process, which is a big part of the motivation to do it, as well as the fun.