While home from university I found my LEGO MINDSTORMS set and decided top build something with it. Recently having been on quiet a few video calls, and wanting to build something useful, I came up with the idea to build a webcam that keeps my face in frame. A FaceFollower.
I originally planed to use Azure's Computer Vision API for facial detection. But the free version was to "slow" and I switched to Emgu CV, a C# wrapper for OpenCV. It's less accurate, but makes more than up for it in speed.
The LEGO design went through several iterations, one with custom 3D-printed gears, before I finally settled for the simpler design I have now.
To control the robot I used functions from AForge.NET robotics for LEGO library.
A more detailed story of this project, as well as a demonstration video, can be found on my blog.