The smart home world is moving from Zigbee to Matter/Thread. Is it a good thing, from the point of view of an Apple Home + IKEA user? I have a bunch of IKEA Zigbee devices, the Dirigera Hub, and I’m trying to understand how to connect everything together correctly.

Zigbee

All devices are ultimately connected to a hub (also called a coordinator). This forms a single-point-of-failure: if it goes down, all devices go down with it. In practice that rarely happens though. Zigbee mesh also supports routing, e.g. IKEA TRETAKT plugs act as routers as well. That means that you can use TRETAKT plugs to increase the coverage area and to “bring the signal closer” to your end devices, such as switches and motion detectors.

Device OTA is questionable: IKEA has a great record of OTA but other vendors vary.

Visualizing the mesh: no idea. Possibly via Home Assistant, but with gotchas. If HA has a Zigbee radio with devices connected to it, then it’s apparently easy (never tried it myself though): Go to Settings → Devices & Services → Integrations → ZHA → three dots (…) → Configure → Visualization tab. However, if all devices are hooked to Dirigera, does it work? The recommended way to connect from HA to Dirigera is by enabling Dirigera Matter Controller (this should also expose older Zigbee devices such as TRETAKT) and then adding Dirigera Hub to Home Assistant via Matter, using the Matter setup code obtained from the IKEA Home Smart app. However, I have no idea whether the visualization works in this setup.

Easy To Understand

Zigbee is easy to understand: all devices connect to exactly one coordinator and form a mesh automatically. If you need better coverage, add more router devices such as IKEA bulbs or plugs.

To figure out which device is connected to which hub/coordinator, just examine the device (either in Apple Home or in IKEA Home Smart App) and the app will tell you the hub right away. That way, you can easily check how far the device is from the hub, and whether it would benefit from additional router devices.

Adding a Zigbee IKEA device via IKEA App automatically adds it to Apple Home. The only disadvantage is that you need IKEA Home Smart App to be installed on your phone.

However, adding Zigbee device from one manufacturer to other manufacturer Zigbee hub can yield varying success - it may work or it may not work.

Matter/Thread

Matter/Thread was designed to solve the device interoperability: any Matter+Thread device should work with any Matter+Thread hub. Matter is a protocol allowing for the devices to speak to controller; thread is the underlying network designed to connect Matter devices, and to route Matter messages between the devices on the mesh.

The communication goes as follows:

[Your Phone] → [Matter Controller] → [Thread Border Router] → [Thread Mesh] → [Matter-over-Thread Bulb]

• Matter Controller is an Apple TV device, connected to iCloud, so that your phone can access it from anywhere
• A HomePod (Mini as well) and the Apple TV itself acts as Thread Border Router. All Border Routers are linked via LAN; every Border Router keeps a mesh of radio-controlled devices.
• A light bulb (or anything powered from a wall) also acts as router, extending the mesh.
• A battery-powered switch is an end device, connected either to router, or a border router via radio.

Looks good on paper - you have a bunch of Thread Border Routers such as HomePod or Dirigera, a bunch of thread routers such as IKEA light bulb, and a bunch of end devices like switches, and Thread will make sure everything stays connected to the nearest border router or router, right? Wrong.

Fucking Complicated

You first need the Border Routers to all belong to the same Thread network (they must share the same thread credentials: the same Extended PAN ID which is a unique 64-bit hexadecimal value that all devices/border routers on the same mesh share). What’s completely ridiculous is that Apple Home doesn’t show the Thread Network identifier in any shape or form, so you have no fucking idea what it’s supposed to look like and how to check whether Dirigera finally joined the thread network with Apple Home or not!

You see, by default, every Border Router (including Dirigera) tries its best to stay independent and to form its own independent Thread network. This goes to ridiculous extremes: in my case, I enabled Matter on Dirigera, integrated it with Apple Home (allowing me to control IKEA Zigbee devices from Apple Home), and Dirigera still created its own Thread network - it shown some IKEA’s own Thread network ID in the IKEA App). Which means that Matter devices hooked to Apple Home silently won’t use Dirigera as the border router even though it may be the closest one!

It gets even better: you add IKEA device straight to Apple Home, it doesn’t show in IKEA app. You add IKEA Matter device to IKEA app, it won’t show in Apple Home unless you add it also to Apple Home - so you need to add the device two times, both to IKEA and to Apple Home - what the fuck? Wasn’t Matter/Thread supposed to be an improvement over Zigbee?

This hilariously (probably) finally forces Dirigera to join with Apple Home: after I added IKEA Matter device to IKEA app first and then shared it from IKEA app to Apple Home, DIRIGERA Thread network ID changed from whatever it was before to MyHome982174339 or similar. I still have no proof that Matter devices will now use both Dirigera and HomePod (whichever is closer) as a border router, because it’s not possible to confirm that they share one Thread network, because it’s not fucking possible to visualize the god-damn thread network mesh!

Dirigera joining Apple Home thread network is no simple process under the hood: you need IKEA app to fetch Apple Thread credentials from iOS Keychain and use something called multi-admin sharing which requires Thread 1.4+ which supports mesh merging… I’m sorry in which fucking way is this simpler than Zigbee? I mean sure, it’s a bunch of clicks in IKEA/Apple Home app, and then you can’t verify that the networks are joined anyway, fucking awesome.

I’m sorry but at this point I completely lost any interest in Matter/Thread. Too bad this shit is the future now.

No Way To Visualize

Of course Apple Home iPhone app doesn’t show shit since it’s dumbed down as much as possible; IKEA doesn’t show shit either; and neither does “Eve for Matter & HomeKit” - it shows all devices as disconnected for some reason, which is just ridiculous. I was hoping to hook Home Assistant into this madness to shed some light, but this is where things fall apart completely: apparently you need to hook into Thread diagnostic mechanisms to obtain the thread routing tables and to see how the mesh looks like, but you can’t do that from just a computer on your LAN (because of security) - you need to connect to Thread via radio (that’s how nRF Thread Topology Monitor does it).

Yes. In other words, in order to see the devices in your home, LAN connection is not enough, you need a radio device. Brilli-fucking-ant!

On top of that, Home Assistant integration to Apple Home is limited:

• you can expose Home Assistant devices via HomeKit Bridge - but I have no HA devices so this is useless to me.
• You can try HomeKit Controller in attempt to control devices hooked to Apple Home, but that doesn’t work because HomeKit accessories can only be paired to one controller at a time (this is an Apple HomeKit restriction).
• or, you enable something called “OpenThread Border Router” as HA Add-on, buy a Thread radio device, connect it to existing Apple Home Thread network (via HA Companion app which should be able to extract the Thread IDs)… but nowhere it is written that this finally gives HA access to the thread network and you’ll finally see the visualization of the mesh. So, lots of work for uncertain outcome - fuck this shit.

But Hey, At Least OTA Works!

True - if you add IKEA Matter device straight to Apple Home via Home iOS App, the OTA updates will work. But OTA support is optional: a Matter device may not be configured to receive OTA updates, and then it won’t receive those, ever. Luckily, both Apple devices and IKEA devices receive updates regularly.

Conclusion

To make sure your devices don’t waste battery life by connecting to some remote router:

• on Matter, you either buy some radio thingy and fiddle with it, in hopes to see the mesh, or you just pray that Dirigera somehow joins Apple Thread network and that hopefully enables the devices to connect to the closer Border Router.
  • Alternatively you use Apple HomeKits as Border Routers only, expanding the mesh via Matter-enabled IKEA plugs/bulbs.
• Or you just get one Zigbee hub, a bunch of IKEA bulbs and plugs, and let the mesh form itself. Easy.

It gets even better: Zigbee routers don’t talk to Thread routers (duh) so you can’t upgrade your home mesh gradually. Brilliant!

If Matter/Thread wants to be usable (on Apple Home):

• It must provide a clear list of all border routers in effect. I hate to guess and I hate not being able to know.
• When a device joins one border router, it must join all associated border routers / controllers / apps. If I add a device via IKEA app, it must appear automatically in Apple Home (as it does with Zigbee).
• It must not dumb down the UI interface to a point where you have no idea what’s connected where: if you start having issues, you must be able to diagnose those.
• It should print the routing tables, or at least show the current border router for a particular device, so that you can verify that Dirigera is being used.

Zigbee checks all the boxes above, Matter/Thread (on Apple Home) checks none of those. Unless Matter/Thread catches up, it’s not a viable alternative for Zigbee.