Help with Home Automation from scratch based on MyS

[andriej]

HI!

I'm trying to plan my home automation setup to be installed in newly built house.
i want to base it on Arduino MEGA (so no PLC, KNX etc.) with support of MySensors also. Controller, so far, will be the Domoticz.

The number of relays needed are still to be planned, but I'd like to plan the main controller first and relays for it.
I'm planning to use:

• Arduino MEGA as controller, with simple digital input-to-output software
• Arduino MEGA screw shield for better connectivity and service ( )
• Omron relays (still can't decide between http://www.aliexpress.com/item/DIN-Rail-Mount-16-SPDT-Power-Relay-Interface-Module-OMRON-10A-Relay-12V-Coil/1986494070.html and http://www.aliexpress.com/item/Slim-DIN-Rail-Mount-DC24V-Source-PNP-32-SPST-NO-5A-Power-Relay-Module-PA1a-24V/32387046628.html )

Now I'm also looking for a way to opto-isolate the switches on the wall from controller, so no interruptions/electric risk are straight on the MEGA input pins.
Basically my idea was to duplicate the relays, so:

12/24V ethernet --- [doorbell switch in room] --- closes the circuit on 1st relay board, which (without controller) runs the 2nd relay board and turn on 230V mains light.
After initiation of home I'd switch the MEGA between 1st and 2nd relay board to measure the button press and time of the press (if long -> do some scene). It would also give me an isolation (in form of relay) of the input pin.

If you have better ideas to share how to built everything - don't hesitate to post it here.
Basically, as far as I can get, I want to run everything without any RF except for WiFi for mobile hardware. I want everything to be wired, including door/window sensors etc.

[Wijbe.Fryslan]

Safety is a great thing! For me, I sould use a relayboard with optocoupler. When good designed it 's a perfect isolation between electronica and 230 AC.

[andriej]

@Wijbe.Fryslan so I guess you have already installation done?