I fear my question might be rather simple, but I haven’t found a clear solution for met yet. I’ve got a standard two-way wall switch setup, and I’d like to make it smart and integrate it into Home Assistant. I don’t want to replace the existing switches or the light bulb, I could however replace switches with momentary switches. In my opinion, I can really only add a module behind the first switch, where I have live, neutral, and ground available. In theory, I could also add something behind the second switch, but I don’t have any neutral nor permanent life wire there.
Here’s a sketch of my current setup and what I’m aiming for:
Is there a module (like a Shelly, SONOFF, etc.) I can install behind that first switch to allow both manual control and Home Assistant integration? I’m fine with flashing Tasmota, ESPHome, or anything else to eliminate cloud dependency.
Any suggestions or proven setups would be highly appreciated! Thanks alot!
Hmm, could you explain a little bit further please?
Ohh, you mean, a relay in the fitting, that can also be controlled via the switch and Home Assistant. Then I’m wondering again tho, I don’t have any permanent life wire up there afaik. Hmm…
Issue with what you showed there is, I don’t have an L or N at the switch before the lamp. I need some kind of solution at the first switch, because only there I have a L and N
You should be able to basically do the same thing as in the picture but move the shelly relay into the first switch box instead of the light (assuming you have enough room in there).
from your drawing in the first post you already have a “2-way switch” (what we call a “3-way switch” in the US).
I think this would work with a 2-relay module behind switch S1.
This is because S1 doesn’t control the light, it controls power to switch S2, on either the (let’s say) red or black wires.
To make this “smart” you need two relays, one that energizes the “red” wire and one that energizes the “black” wire so that either red or black wire is always energized. When Relay R1 is on, R2 must be off, and vice versa. Switch S1 can be used to manually signal the relays to “swap” places, to mimic the existing switch.
I believe Shelly dual-relay modules have a “motor” mode to interlock the relays so that only one is closed at a time. You could also flash a Sonoff module with ESPhome or Tasmota to have complete control.
Edited to add: you can create a template switch in HA to toggle the relays to control the light, but knowing whether the light is actually on or not, would require a current (or energy) monitor. The template state will be true whenever the power draw is over some threshold.
Thanks alot!
