This was a bit of a fun project - I've seen on the movies (or maybe Scooby Doo) pictures where the eyes follow you and wanted something similar in my house.
Also, from a practical standpoint, I often get caught out without an umbrella in rainy England so I wanted something that would tell me the chances of rain before I left the house.
What I came up with was the project that you see in the video above. As with all the devices in my house, I relied on the ESP8266 microcontroller - it's consistently proven to be stable (I now have 8 of them doing various duties within the house 24/7) and is really simple to program for.
The person sensing is done by an Adafruit AMG8833 sensor - easily the most impressive I2C device I've seen to date. This provides an 8x8 thermal image that the ESP8266 uses to determine the position of the eye servo.
The weather updates are provided by the DarkSky API - I used to use Weather Underground but they've closed their service to enthusiasts. The updates/servo positions are pushed from a server running NodeJS to the device every hour.