I like how the LEGO Spybotics series from long ago just made the bot/PC connection use light for some reason, instead of making electrical contact. Probably made it way more tolerant of a poor connection, actually.
@NovaSquirrel Here, there's an article:
https://en.wikipedia.org/wiki/Opto-isolator
@rainwarrior Yeah after reading about it, it sounds like a very sensible and useful design.
I also forgot that the generation 1 LEGO Mindstorms uses infrared to communicate with the robot too, and in general it feels like they reused engineering for this Mindstorms subseries.
@NovaSquirrel It's one way to make a buffer for a signal, to isolate both sides from each other.
E.g. there's no way a power surge can damage it across that.