Yeah, I was thinking one Arduino and all of the sensors homerun into that one Arduino. Basically I'm trying to avoid the $1564 price tag (closer to $284).
That expander is exactly what I hoped would exist (but didn't know what to look for).
[quote author=Nick Gammon link=topic=129062.msg971205#msg971205 date=1351200437]
Sounds like an overkill, especially if it just raises an on/off signal.[/quote]
When you say "sounds like overkill" do you mean a simple 24 gauge pair (or however many wires are needed) would usually work for something like this?
If there's a likely chance that this idea would work, I can move forward. I didn't want to get started and then find out something like "everyone knows that only jumper wires shorter than 1 foot would work" or something to that effect.
Knowing that technologies like RS485 exist is exactly the type of info that I was missing.
I'm going to be experimenting as soon as I can get some stuff ordered. Thank you so much for responding.
- Peter