11
Mar, 2024

A Zigbee back-and-forth without neutral and additional wireless

Objective and constraints

On this RetEx, I set the bar quite high, I would like to replace an existing back and forth, so with two wires shuttles by one back and forth domotized Zigbee without having to add thread.

Please note that I have not Not Neutral switches.

The only deviation I allow myself is to replace the switches with push buttons.

An original back-and-forth

So with each switch I have 3 wires, the two shuttle wires and a phase (red wire) and to feed the lamp, the orange/yellow wire.

I want to domotize this in Zigbee

Most home automation back-and-forth solutions require adding a wire between the two switches, as I have an inaccessible bypass box, I cannot add a cable between the switches, so I looked for another solution.

I had a first help from Doubledom with this diagram. Then a second of BBE on this Tuto. Thanks to them.

I adapted this to the last unneutral Sonoff Zigbee, i.e. ZBMINIL2, it is really very small and cute.

My new scheme

The purple wires are the old back-and-forth ‘shuttles’, one will lead the phase to the mini module and the other will either be ‘in the air’ or receive (by pressing a push button) a phase pulse which will be transmitted to S2 of the mini module.

I set the command type (monostable)

I'm flipping it. ZBMINIL2 in ‘mono-stable’ mode, that is to say, I inform him that it is not controlled by switches but by push buttons. By default, it is bistable, i.e. a two-position switch.

For this, very simple, it is in the leaflet, you press the button 3 times and the mini module pays by blinking 3 times, I control mode is changed. (thank you again BBE)

I integrate the module into Zigbee2MQTT

I'm pairing Zigbee2MQTT.

Very classic, I press the module button for a long time until the LED flashes.

The mini-module is quickly recognized.

I go to Home Assistant to find my equipment

Very classically, I changed the ‘display as’ parameter to turn the control into ‘light’, which is simpler for the management of this equipment and for the link with the voice assistants.

I'm testing

The domotised back and forth works perfectly and I can have the state of my light in HA. I can also drive it via HA. Perfect!

 

Comments ? need clarification or explanation ?

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