Building a Home Surveillance And Recording System that is Right for You
With some modification can be for a bus. But this is a good spot to start to learn what you need. Lots of things can be connected to a security system... like a gizmo that will tell you if your plumbing is starting to freeze solid.
More info on building a custom system. It's not just for security and it doesn't need to cost you $1K and up!
BTW,I did buy my old, old
Visonic Securelink security system (no built in GSM dialer but basically they still sell an updated version) from this place. It's the old X-10 systems but that is perfectly fine for a bus. Not like I have long distances to send a signal!
What is Home Automation may have things that will work for you on your conversions. Like dealing with the lights and the thermostats to name just a couple.