I've seen a bunch of projects involving dozens (or hundreds) of LEDs being controlled by an Arduino. How does this work?
I imagine it somehow needs an additional controller with more i/o pins... What sort of addon would I be looking for if I wanted to do this? Can everything still be controlled by the Arduino programming, or would I need to program individual circuit chips?
I'm pretty new to Arduino and electrical engineering in general, and haven't been able to wrap my head around this. I'd much appreciate it if someone can shed some light.