For a while now I have wanted to add a personal weather station to my home automation system. The idea was to use the data collected for things like controlling when my lawn sprinklers run. I also plan on using temperature and humididty data to determine things like heating and cooling (HVAC) operations. In this post I will log the ongoing details of my modular personal weather station project. With the help of my new Anet A8 3D printer that I purchased earlier this year, I was able to use it to build all of the parts needed for the project. The project was started a while ago, but I didn't have a place at the time to post my progress, so here it is.
So far I am working on 4 parts to the weather station. Wind speed anemometer, wind direction vane, rainfall gauge and a temperature and humidity sensor. All sensors need to communicate to my home automation system over my MySensors network. I am hoping that I can control all data collection with a single arduino pro mini built on a MySensors Easy/Newbie PCB created by Sundberg84 from the MySensors forum. In this post I will outline each modular section of the project. All of the 3D printed parts for this have been designed in OpenSCAD and will eventually be posted on my thingiverse page. This post is a work in progress. Check back to see more information.
The anemometer and wind direction vane
The first part of the project that I started with was a combination of two sensors. An anemometer for measuring wind speed and a wind vane for determining wind direction. This is the first prototype design of the 3D printed parts. Some minor changes have been made since this design. The first was to invert the center mount sections so the screws screwed in from the bottom. This put the wind direction vane on the piece with the square mounting peg and the anemometer was moved to the other piece. The reason for this was to keep rain from collecting in the small screw recesses and potentially getting inside the case. The next change which I am in the process of printing as I write this, is a new piece with a round mounting peg instead of a square one. This was done because of a later decision to mount everything using schedule 40 PVC electrical conduit.
The anemometer is mounted with a ball bearing that is press fit into the cap. The shaft, a 1/4 x 20 bolt with a small rotor that has a magnet mounted in one end and that will pass by a magnetic reed switch. The arduino will use the counted pulses from the reed switch to determine the wind speed. The anemometer cup design was borrowed from a project on thingiverse, but I can't seem to find the original that I used. The cups, arms and main shaft attachment are all separate printed parts that I have glued together. This made for an easier build on my 3D printer.