It is not perfect, but the best Matter switch I’ve found so far, for Australia, is the Matter over Thread series by SmartSetup (also available on Amazon).
I’ve previously reviewed a few Matter inline switch modules, including the Sonoff MINIR4M and Zemismart ZME2 dual inline switch, however all older ones are WiFi.
Now Thread-based switches, and inline modules, are starting to appear on the market, and will be a key element to building the mesh backbone of a Thread network.
This article will go through a few of the reasons why the SmartSetup is great, considering external switches vs inline modules, Thread vs wi-fi, and support for detached relay/smart light mode.
I still think there are improvements to be made, so I’ll finish with a discussion of Matter control Binding, and an outline of my ideal device.
External switches vs inline modules
An external switch has some advantages over inline switches as they know the physical mechanism they are wired to and so can easily support momentary pushes, alternatives like long presses, displaying the status (via an LED), and physical controls for restart/reset, i.e. withouthaving to open up the wall cavity or turn off the power at the switch board.
The SmartSetup switch takes advantage of this in the current model by having some small dip switches, behind the face plate, for setting detached relay/smart light mode that can be configured after installation, and by allowing device reset via a long press on the button. The Matter QR is also visible if you take the faceplate off.
The major disadvantage is styling -- with an inline switch you can keep your existing faceplates and have consistent style throughout the house. Inline switches can also be sold to multiple markets where external switch form factor varies from region to region, i.e. a US switch is a different size than standard Australian switches.
Commissioning tip: It seems Google still hasn’t quite solved issues with multiple Thread Border Routers. The first switch I commissioned worked fine, but later when I commissioned the second it kept failing and I had to turn off my extra Google Hubs (leaving only one on) for it to work.
Thread vs wi-fi
Many existing switches and relays, with permanent power, are wi-fi, however for supporting battery operated kit, such as sleepy end devices, Thread has much lower power requirements and is a better solution.
But you need a backbone of permanently powered devices to form the Thread mesh network (more than just a couple of border routers). Without that backbone, the use of battery devices is limited.
Thread-based switches are a great choice for building your mesh network. They will always have power, so can form a stable mesh network with your border routers for any end devices to utilise. The usage of Thread-based switches, like the SmartSetup, are important for the development of a Thread ecosystem.
Thread-based light bulbs such as Nanoleaf can also help form this mesh, but only so long as you remember to leave the power on.
Of course, Thread also utilises the latest Internet technology, running IPv6.
Detached relay / smart light mode
Smart bulbs are quite common, because they are easy for end-users to install (and more fancy, with colours), but the big drawback is that they need power. When the rest of the household just flicks them off at the switch all the smarts are lost.
This is where smart switches (or relays) come in, although in Australia you need a sparky (electrician) to install them. Even without a smart bulb they allow you to set up routines to turn the lights on and off automatically (my wife’s studio is set up this way).
When paired with a smart bulb, it also means an automation can first turn the switch on, then configure the light, e.g. for a particular mood.
However the SmartSetup switch supports an even better solution, with a smart light mode. A dip switch behind the face plate (and so configurable without calling a sparky) allows you to turn on permanent power to the bulb. You can then set up an automation in your Matter controller so that the switch directly turns the smart bulb on or off. There is sometimes a short delay, but it means the light is always available for advanced scenes.
As a bonus, if you are using a Thread-based bulb you get an even stronger Thread mesh, with both a permanently powered switch and a permanent powered bulb.
Note: The Sonoff MINIR4M which also has a detached relay mode, but only exposes the relay to Matter, not the switch, so a Matter controller doesn’t know when the switch is pushed. So the Sonoff detached relay functionality only works in their proprietary app.
Matter switch binding
The Matter Core specification has an even better solution that allows an On/Off Switch control to bind directly to an On/Off actuator such as a light. This means the switch can control and subscribe to the light directly, without needing a hub.
Because the switch can subscribe to the light it also means if you turn the bulb on or off directly the switch will know, e.g. to display an indicator.
Further, in the Matter Device Library specification for control device types ‘manufacturers are encouraged to implement an additional endpoint on the same product holding an "actuator" device type’, meaning both the control switch and the detached relay will be available for control.
Currently the SmartSetup, when in smart bulb mode, only exposes the control switch, but I can always hope a future software update fixes that.
Note: The Zemismart inline module node configuration says it implements the On/Off client and Matter binding, but I haven’t been able to get it working yet.
Current ideal device
My ideal switch device doesn’t yet exist in the market, but the SmartSetup is close:
- External switch form factor (I’m in Australia, so Australian form factor and certification).
- Thread-based, to build a stable mesh.
- Accessible physical controls for device restart and factory reset (the SmartSetup only has reset).
- Accessible physical controls for power on/off in detached relay mode (the SmartSetup dip switches are not easy to access or change, and removing/replacing the face plate can trigger factory reset).
I would probably have the main button do smart on/off and then long press for relay on/off, with a separate small restart button maybe on the side of the switch (that can also be used for factory reset with a long press)
Features I want that no devices have yet in their firmware (and Matter controllers don’t yet support well):
- Support for Matter Binding and On/Off client, so that the switch control can directly send commands to a smart bulb.
- Separate Matter endpoints for the switch controls and switch actuator relays, for full detached relay functionality.
- Standardised way to control detached relay mode via Matter configuration.
An ideal device would also have power monitoring capabilities, although that would need additional hardware, not just a firmware upgrade. And for completeness providing a way to flash with your own alternative firmware would be a bonus.