The alert box consists of an Freetronics Etherten (Arduino Uno clone) with an LCD display shield wrapped in a 3D printed enclosure. This provides the ability to read JSON or XML feeds from the internet and display digitally on an LCD screen.


An analog notification was added by squeezing in a servo which raises a flag from the rear. This has also been proven to attract nearby cats.

Source:

Thingiverse STL files
Github Arduino code