The ultimate concept of this poject is to have a robot base that is entirely controlled by a single serial bus, such as RS-232, RS-485, or USB. All control of the base would be through this serial channel and the sensors would issue alerts if there is a fault. I suppose I should make such a thing selectable with settable tolerances for the alert.

USB would be ideal as it is a very common interface. However, I think I will still include RS-232 as it is so ubiquitous.

Sure. There are other robot bases out there and I could just buy one. But then I wouldn't have had as much fun and I certainly would not have learned anything.

I have actually written quite a bit i=on this in my engineering notebook. I'll be transferring the notes to this page as they get better fleshed out.