Do two way communication smart ZigBee switches exist?

Question

Previously posted on Home Improvement however it received no responses.

I have "smart" ZigBee lightbulbs throughout my home, as we like being able to change their colour using Alexa. I also have, but do not use, "dumb" physical light switches, as when I turn the bulbs off at the switch it stops Alexa from being able to control them. I would prefer to have full local control, as whenever the internet drops out we currently cannot control the lights. Furthermore, most nontechnical people are used to turning on lights with a physical light switch.

I live in England so cannot use the US shape of light switch. I am happy to change my light switches to soft switches - the ones that illuminate an LED when you touch them - however I need that to be a ZigBee input rather than a physical power control.

How do I turn the light on and off with a physical switch, but also still allow digital control, such as Alexa and app?

Answer 1

There are plenty of Zigbee switches that will allow you to control lights.

They range from very basic (On/Off) to more complex (dimmer, or multiple buttons for multiple scenarios). Some are battery-powered, others are even battery-less (Zigbee Green Power) and use the energy from button presses to power themselves.

Some are designed as small remote controls that you can have anywhere, others are designed to be put on a wall, or integrated in a wallbox. There are also modules you can put inside an existing wall switch which detect when you use the switch (which is disconnected from mains, so doesn't actually switch off the light directly).

Note however that contrary to lights where you can connect nearly any Zigbee light to any Zigbee network, the Hue bridge for instance only knows about Hue switches. Other bridges/solutions are often more tolerant.

The Zigbee Device Compatibility Repository lists hundreds of switches, dimmers, remote controllers, along with compatibility with some of the gateways.

Answer 2

(Based on my answer from the original Home Improvement question but changed to match the slightly altered question here.)

I expect most of the zigbee based systems work locally, Philips Hue and Ikea Trådfri stuff does. I think your problem is with Alexa. (We can clarify if you give details of what system you're using.)

Assuming you have or change to a zigbee setup that works without the internet you may then just want to use switch covers to encourage people to use the zigbee switch instead of the dumb switch. I've put more details in my Home Improvement answer.

If you want to use the normal light switch to control the light and have digital control you could use a Shelly device. These use wifi and control a normal lightbulbs. They sit in the back box behind the switch and can be wired up to take the dumb switch as an input. There are options for if you don't have a neutral but it does get a bit more complicated. There are several products depending on what exactly you need.

I mention this specific company as its the only one I know of that allows you to use a 'dumb switch' as input, possibly there are others. I have one of these but haven't installed it yet.

They seem to have the usual integrations including Alexa. I don't have an Alexa like device so can't advise on that part but a quick Google turns up results for how to configure them to control smart devices while offline.

Answer 3

I don’t know any specific products, but I would fathom that you need a light bulb with an internal battery that keeps it alive for some time after you turn it off.