Things I've designed and built: electronics, 3D printing, software, and combinations of all three.
The Zoominator is a box that lets me control my camera/mic state in Zoom (or Gather) calls externally.
Promptulatron is my set of enhancements to my Elgato Prompter which adds a circular polarizing filter and a privacy cover to the camera.
My first Arduino project was adding TOS-accurate flashing lights to a model of the Enterprise.