Carl Monk’s really done a great job on this.

Here’s an ISS tracker using a Raspberry Pi and the 8×8 Neopixel matrix of a Unicorn HAT. The Pi reads in the current co-ordinates and then plots the position on the Unicorn which has a paper overlay of a map of the Earth. It uses a different colour when it’s on the ‘non-visible’ side of the Earth. Carl has open-sourced all the code and the paper overlay and has posted it to his blog with an explanation of the project. Read about it here. You can see a short video of it working below: