Anemometer

Anemometer constructed in FreeCAD. Several parts who all fit together. Top can be glued on. All screws are 3mm - various lengths needed. Also a ball bearing is needed, I used a 8x22x7mm one from AliExpress. A small press-in part in the lower part is used to hold up the bearing.

Take measurements by placing a hall sensor into the lower part and a small magnet in the upper rotator part.

Lower part has a holder for a Rasberry PICO built in, but any other microcontroller can be used.

I also write about this in my blog: https://outpost.garf.de/wordpress/index.php/2021/04/17/building-an-anemometer-part-1/