ISS pointer

This is intended as sort of a useless desk toy that points at the location of the international space station in the sky. You can also tell it to point at other things, of course. Final goals are to make it fetch TLE data from the internet, and allow the user to wirelessly tell it what to point at. https://www.youtube.com/watch?v=brCzEvc-sUg
https://www.youtube.com/watch?v=FkDNPca6eOw

Currently: It's hard coded to point at a specific satellite. There's not enough program memory in arduino 328 to also fetch data from the internet while calculating orbital parameters. I'm using the 28BYJ stepper drivers aka darlington arrays, which means the steppers are really weak. This is only a problem during homing, which can be fixed by just making the homing speed slower. Although weirdly enough the homing seems to work flawlessly after a bit of a warmup period.