Make Switches and/or lights smart


I’m thinking about making my lights smart (with openhab as server).

But I have some problems understanding the possibilies and the pro/cons of the different solutions. And searching the net and the forum made me a bit smarter, but couldn’t answer all questions.

I pay rent, so everything I do should be reversible. What I understand I have the following options:

Option A
I keep the standard light bulbs and the standard wall switch.
I use a relay like FGS-233 behind the wall switch to make the switch smart.


  • The Wall Switches can be operated normaly
  • It still works even if my openhab server is down


  • I cann’t use smart lights like tradfri or hue, so I can’t make use of different light temperature tec.

Option B
I just use smart lights like tradfri or hue.


  • The wall switches need to stay on always on

So this is not an option for me

Option C
I use smart lights like tradfri or hue.
I replace the wall switches with Z-Wave Wall Switches


  • I can use smart lights
  • The Wall Switches can be operated normaly


  • If the openhab server is down, it’s impossible to turn the lights on/off
  • The wires behind the switch need to be connected to make the bulbs always on

What wall switches would be useful? Are the Wall switches, that can be powered by the existing wires behind them? That would remove the need to use batteries and would make the switches be uses as Z-Wave HOP.

Are there any other options that are possible?

Option C is likely wrong in the “CON” re operating the switches. If you have an upstream smart bulb from an automated switch and OH is down, most smart bulbs will operate as dumb bulb is power is applied/removed. I.e., if OH server is down you could still use the switch as a manual switch to do basic operations with the bulb. Not ideal, but your basic ON/OFF should still work.

That being said, given that it is a rental, I’d be inclined to use a mix of z-wave modules that plug-in a socket for lamps etc and smart bulbs for permanent fixture lights.


  • For lamps etc, No need to open up the wiring behind the switches to either replace the switch entirely or add an in-box relay/switch behind the extant ones. If the outlet is a switched outlet, and OH is down, toggle the mains dumb switch for the outlet should put the plug-in switch into ON. You would have to verify this with the particular plugin model. Worst case, all the plug-ins I know off have a manual override on the plug-in itself.
  • For fixtures, smart bulbs would be your best bet, but again verify behavior when power is physically cycled.
  • Everything is portable when you move


  • Probably a bit more expensive than simple smart bulbs, but not necessarily.

Have you looked at the sonoff wi-fi switches? No hub needed it communicates with openhab via MQTT. You can flash tasmota firmware and use GPIO pin 14, connected to existing wall switch, if wi-fi or server is down. I have several and they work great. Only CON is sometimes its a tight fit and you have to remove the plastic case and use tape for protection.

Those would fit the Option A only, the desired ligth temperature can not be set by those switches!

Here is a list of options for the firmware, SetOption 15 mentions color/dimmer control.

IMHO that relates to LEDStrips running on Tasmota.

Thanks alot, I’m getting a better understanding of what I’m trying to do :slight_smile: