Would it be difficult to “make” some zigbee dc powered push button module ?
The goal is to reuse my wall switches (momentary push buttons) and incorporate a zigbee module that could be powered by some cabling running the walls from switch to switch.
The actual cable running from switch to switch is a 6G0,5. Once the actual switch system is gone, I could use those 6 wires to bring power.
I looked for days on the internet and didn’t find any zigbee module that could be powered by a small DC instead of the 230AC.
Maybe get rid of the AC part of an existing zigbee module would be easier but I never opened one of them to see if it is actually possible.
I would need up to 4 input by module.
I don’t need the relay part of the module I find online.
Why you want dc wiring instead of 230AC?
You could use battery powered SONOFF SNZB-01 ZigBee button and wire it to your existing (momentary) wall switches. Remove the battery and make 3V dc wiring.
DC instead of 230AC because of the size of the wiring.
This is 0.5mm² wire. I night melt them if anything happen. I would like to avoid putting my house on fire, if possible
The sonoff button is a possibility but I would like to use my existing momentary wall switch (already in place).
Also, the actual button location are quite good. I would need to cover the actual button location to put the Sonoff button. Not really convenient :-/
Also, the wiring size for low voltage is higher than for high voltage. That’s the reason we use 230V instead of 12V in our houses. 12V wire for same power would be 20 times “thicker” than 230V wire.
Ok !
Now I get you
I guess I could order one and see if it could work.
About the power, I’m afraid of running high voltage in small wire. I get that an issue would come from a overload, not from the wire size but, anyway, 230V wires must be at least 1.5mm² to be rule compliant.
That’s ok, 230V can kill you, 3V not. And I agree for rule compliant.
I just commented about your concern of melting wires with high voltage. The truth is opposite. For 500W load at 230V you have 2.2 Amps on your wiring. For the same load at 12V you have 41.7Amps. Your 0.5mm2 wire would be ok at 230V, but would definitely melt at 12V.
Also DC voltage is more dangerous than AC voltage because of arching.
But for your low power low voltage button you don’t have to be worried about anything.
At this point you need to clearly describe, how is the whole system being powered? You use zigbee to control separate zigbee relay, or you still need to switch 230VAC with these “buttons”??
There is too much room for confusion…
I will try to clarify
For the time being, the system in place is composed of
an analog bus going from switch to switch (6 x 0.5mm² rigid wire)
some address modules, connected to the bus, using momentary push button switched to get the “pulse”
some kind of relais, at the other end of the bus, in the electrical box, switching on and off the lighting points, all connected to the electrical box.
The actual “switches” do not physically switch on or off the power to the light. Instead, they are used to send a command to the relais.
My goal is to get rid of the analog bus (address modules and relais) and use Zigbee instead.
My plan is to use an IKEA Dirigera hub to link all components and make the lighting system available from HA. It could work even if HA is down for the basic functions but HA would help me build complex scene or scenario if needed.
I have found some nice zigbee relais that could be installed in the electrical box (to replace the analog bus relais).
I have the push button in my walls. They are basic but they are working nice and are the same design as the rest of the electrical sockets of the house.
I “just” need some Zigbee module that I can install in the walls, behind the switches. Those Zigbee modules could be powered by the current analog bus cables.
perfectly,
then SNZB-01 and the one walberjunior linked could be your choices.
You just use old wiring to supply 3V (or 3.3V) to them.
If you don’t have enough space behind the physical switch, you can use old wiring to locate your zigbee buttons to most convenient place.
You might need to solder the switch wires to zigbee buttons.
I am doing something similar but inside my campervan.
I already have the Sonoff buttons and they work great.
But I want to hide the button behind my dashboard as I already have a ‘cab light’ button the the dash which is redundant as the lights have been removed.
As the van uses canbus, the button sends a ground signal when pressed.
This signal is enough to enable a latching relay as I have modifed 2 of the buttons to do this already. By the ground pulse, it latches the relay and press it again, it unlatches.
So I have the ability to send a momentary ground pulse by doing this.
I bought a standard relay to be able to use a 12v relay enabled by the button grounding it to pulse a 3v signal from the Sonoff button.
But when I opened the sonoff button, I realised I would need a DPDT relay as the button inside is 4pin. Any idea why that button is 4pin? Is it switching the 3v also?
I was thinking of using a 2ch octocoupler but worried the resting power consumption would quickly drain the button cell.
I have modified a cheap AliEx Tuya zigbee switch to run from 12V as a detached switch. I removed all the mains circuit (and the relay) and added a small DC-DC module to provide the 3.3V. It works fine and as a bonus it is also a zigbee router.
Very neat solution !!
On my side, I went to ESP32-H2
Since a few versions ESPHome supports the Zigbee stack. It is A LOT easier now.
The ESP32-H2 Mini est very small, cost effective, easy solution (and it can be router too )
