This is one of the easiest sensors I’ve built. Basically it is a 10k 360 degree potentiometer with a wind vane attached to the top. I set North equal to 0 resistance and then record the values through testing at the other directions and then split the difference between them. (Will explain this more when I do the coding part)
Here are the two main parts to the sensor. A Bourns 6639S-1-103 10k rotary potentiometer and a Davis instruments wind vane with brass tip for Vantage Pro2 anemometer. You’ll also need some cat3 or cat 5 cable, a 1 1/4″ to 1″ PVC “T” and two 1 1/4″ PVC plug.
First you want to drill a hole in the middle of the PVC plug for the pot to go through. (Make sure you can get all the threads through the hole).
Before you tighten the pot into the hole, you’ll need to solder some wires to the bottom of the pot. For the Raspberry Pi, you only need one on peg 1 and one on peg 2 (Power on peg 1 & read on peg 2). For Arduino, You’ll need to attach a ground to peg 3 of the pot. Make sure and use some shrink wrap to protect the joints.
Once your soldering is done, tighten down the pot into the hole and slip your wire through the “T”. Make sure you mark “N” on your plug where 0 resistance is read after the pot is tightened down. Keep your pot adjusted to this position. Slide the plug into the T. (Place another 1 1/4″ plug in the other side).
Finally, you’ll need to attach the vane. The vane has a small Allen screw in it. You’ll need to loosen it up before you slide the vain onto the post of the pot. Adjust the vane so it’s just barely off the plug, point it towards “N” that you marked on the plug and tighten it down.
As far as wiring this sensor, the wire soldered to peg 1 should go to +v, the wire soldered to peg 2 should go to either an read spot on your ADC (if you’re using a Pi, something like the MCP3008) or to an analog read pin on your Arduino, and the wire on peg 3 should go to ground (if it’s connected)
I’ll share the reading code part later when I can get on my main computer at home.