How to tackle curious project

Projects General Guidance
1

Hi

I have previously tackled an Arduino project which grew and grew in scope. When it was finished, it was ethernet enabled, could tweet and send SMS, could read inputs from wireless equipment, set its own RTC from an NTP server and control a servo and LEDs. I created it with a lot of help from the community, but I also gave back to the community in identifying and fixing a bug I found in a library. I'm mentioning this so that you have some idea that whilst I'm a beginner, I can learn as I go.

Now I want to create a project which reads inputs from three "control panels" separated by many metres but ultimately within the same residential building.

I want the control panels to contain LEDs which are turned on/off by both switches on the OTHER control panels and/or by magnetic contacts on doors etc.

Please - how best to approach, do you think?

  • One Arduino with many many I/O pins? If so, does an Arduino model exist with enough pins?
  • Three Arduinos somehow wired communicating with each other? I have Googled this topic extensively but I'm still not sure of the various methods which to choose and how to do it. Or even if it's necessary.
  • Three Arduinos communicating with RF/WiFi ? Even less sure if this is reliable and how to do it.

Many thanks for your replies. Go easy on me!

2

It's hard to say without more detail - how far is many meters? Would it be plausible to run wire between the arduinos?

That said, is there ethernet in the building? If so I'd use an Arduino per control panel and an ethernet shield to do the comms. If not, wifi or xBee for preference - RF to save money.

3

There are other interconnectivity options, potentially cheaper than wires
or WiFi, such as ISM wireless transceiver modules like the RF12M, nRF24L01+

Running long wires has issues with noise pickup, drilling holes in floors and walls,
etc, so wireless comms may be advantageous. There are drawbacks though
(security / privacy for instance)

Have a look at the "networking, protocols, devices" subforum perhaps?

4

wildbill:
Is there ethernet in the building? If so I'd use an Arduino per control panel and an ethernet shield to do the comms.

There is ethernet and I would love to use the existing wiring (ethernet in this case) rather than running new.

I'll see if I can find out how to do that.

Thank you

5

There's also LAN or ethernet over mains wiring, but in a large building it's likely that not all the sockets are on the same phase.