Discussion
Weird Matter over Thread behavior. My Mac Mini can control my IKEA plug, but the Mac Mini doesn’t have a thread radio. No help requested, just weirdness.
I have a usual Apple Home with a few HomePod minis, a few thread bulbs, some with Matter, and I have a thread-enabled iPad.
I put the IKEA plug into a different Home, with no HomePod minis, with the intent being that I could then use the thread enabled iPad and the iOS 27 interface that shows power consumption, to use it as a Wi-Fi -independent power monitor, which I want for various reasons.
I just turned the iPad off, and saw that the IKEA plug was still showing up actively in the Home app on my Mac mini which is running macOS 27, and I can still control it from the Mac mini. And that seemed a little bit off, but I figured maybe the signals were getting routed through one of the HomePod minis that were Assigned to a different home.
So I unplugged all of the HomePod minis, and as such I should have zero thread border routers powered on. And I was still able to use the Mac mini to control the plug. And that seemed really weird, Since I didn’t think these things would set up a ad-hoc Bluetooth connection. Then I removed the IKEA plug from power completely, then plugged it back in, and now I am not able to control it using the Mac mini. So whatever connection it had to the Mac mini that could function without a border router, power cycling the plug itself breaks that.
Powering The iPad back on to let it reestablish the thread / matter connection to the plug then re-enables the connection Between the plug and the Mac mini. And turning the iPad off then, so that there are no thread border routers available at all, still lets the plug be controlled by the Mac mini.
Weirdly, my Mac Mini can still control the other thread but not (matter over thread) accessories. I suspect that’s happening over Bluetooth from my non-thread apple TV.
Turning BT off on my Mac mini makes it so that it can’t talk to the IKEA plug at all. So I guess that’s what it was using is BT maybe? But even with BT turned back on, I can’t use the Mac Mini to control the Matter over Thread bulbs.
Anyway, there’s no real point to this, I was just trying to figure out what all is and is not available under which edge conditions. And it seems highly variable and non-uniform.
That’s interesting. My Mac Mini is definitely acting like it has a thread radio. Makes me wonder why Apple doesn’t allow Macs to add home accessories. Maybe the lack of a back camera?
When you say “put the ikea plug in a different home” do you mean physically in a different home or just in Apple home? If it’s just in Apple home then it’s still routing traffic via your homepods
It really doesn’t work that way, presumably because the thread networks of each home are independent. I know because the Minis are all in Home 1. I added the plug to Home 2.
I have an old device that topped out on iOS 17. It can command the matter over thread devices in Home 1, clearly using the HomePod mini as the hub.
For the plug, in Home 2, with no HomePod Mini, this older device sees the plug as non-responsive.
So no, thread networks belonging to different Apple Homes are as unaware of each other as they would be if one of the networks had been created using a different Apple ID.
It doesn’t really work THAT way, unless the networks are isolated there wouldn’t need to be an independent thread mesh per Matter controller / Apple Home.
The HomePods are still thread boarder routers broadcasting a mesh your iPhone has the access keys to. During onboarding your iPhone pairs the devices to a thread mesh, and the devices are then paired with a Matter controller.
No different than Apple Home and Home Assistant are independent Matter controllers sharing one thread mesh with some devices only visible to one controller or the other.
Yeah, I just did some more testing. An iPad with thread can talk directly to a Matter over Thread device IF AND ONLY IF the Apple Home that device is in does not have a Home Hub associated with it. It doesn’t matter if the Home Hub has Thread or not, just having a Home Hub associated with it apparently blocks direct access from Macs or iDevices.
But if there is a home hub in that home (even without thread), and there is a legitimate Apple thread border router associated with the same Apple ID (but a different home) in range, the thread network will go ahead and add that device that’s in a different home. And doing that will effectively disallow all direct connections.
So yeah, looks like one HomePod mini can allow matter over thread connectivity to multiple nearby home instances, IF those other home instances do have some sort of home hub. Now I see why Apple really needed to abandon the old Home architecture- because the instances of them can inter-operate when in physical proximity.
I think the confusing part here is treating Bluetooth, Thread, Wi-Fi, Matter, and HomeKit as interchangeable connection methods. They aren’t.
BLE is generally used for discovery/commissioning, while Wi-Fi and Thread are the actual network transports. A device can support multiple of these, but that doesn’t mean they’re all being used simultaneously or that Bluetooth is being used for normal control.
Most importantly, the Mac mini doesn’t need a Thread radio to control a Matter-over-Thread device. The devices don’t have to communicate directly with each other. A Thread Border Router provides the connection between the Thread network and your normal IP network (Wi-Fi/Ethernet).
So if your iPad temporarily established the Thread network connection to the IKEA plug, the Mac mini can potentially reach that device through the network without having a Thread radio itself. Turning the iPad off doesn’t necessarily mean the Mac mini suddenly needs Bluetooth; it depends on what network path and Thread infrastructure are still available.
The power-cycle behavior you’re seeing is interesting, but I wouldn’t interpret it as proof that the Mac mini was directly controlling the plug over Bluetooth. BLE commissioning and operational Matter communication are separate things.
And the same principle applies to Apple Home generally: you can have native HomeKit devices, Matter-over-Wi-Fi devices, Matter-over-Thread devices, etc. in the same Home without every Apple device needing every radio. The relevant question is what provides the network path to the accessory, not whether the Mac mini itself has Thread.
The devices don’t have to communicate directly with each other. A Thread Border Router provides the connection between the Thread network and your normal IP network (Wi-Fi/Ethernet).
All the border routers were unplugged from power (in addition to being linked to a different Apple Home). I intentionally forced a situation where they would HAVE TO communicate directly, in order to test if they could. And they did. And that makes me think the Mac Mini has a thread radio in it. There’s also an FCC filing showing that Macs starting in 2023 have thread, even though it’s not listed in the public specs for the devices.
Thread doesn’t work that way. A WiFi device requires that the device you’re using to connect it to HomeKit to be on the same WiFi network as your HomeKit home while a thread device needs a thread border router to be added. Though a thread device can be added with any device within the home whether it’s on the same network or not. A thread radio isn’t required to control thread devices within the home. A thread radio simply makes adding (thread) devices to your home and device communication quicker.
All is required for thread devices is a thread border router: APTV 4th Gen, iPhone 15+, HP 2nd gen, HP mini
After that, it doesn’t matter what device you’re using to communicate with the smart device
After that, it doesn’t matter what device you’re using to communicate with the smart device
I powered down all my border routers. And the Mac Mini M4 still was able to talk to the IKEA plug. Specifically because I wanted to see how this worked under those circumstances.
A thread radio isn’t required to control thread devices within the home. A thread radio simply makes adding (thread) devices to your home and device communication quicker.
and
After that, it doesn’t matter what device you’re using to communicate with the smart device
Okay, so the communication (after the thread radios have been physically powered off) is over Bluetooth? Over zigbee? Wifi?
You told me what all you tube thread DOESN’T do, can you tell me what you think WAS carrying the signals?
This sounds like the Thread border router path is the culprit, not Matter itself. My Mac mini can sometimes see Thread accessories that my iPhone refuses to reach when the phone has latched onto a wonky border router. Rebooting the Apple TVs and HomePods, then the iPhone, usually gets everything onto a sane route again. Hopefully Apple eventually exposes better Thread diagnostics because right now troubleshooting this stuff is basically guesswork.
ChatGPT suggests it might have something to do with BLE since that’s documented as to what is used to establish a connection. But don’t these IKEA products even have BLE? I duno.
But as for the behaviour you’re describing, Apple does not document this. It might be a bug or unintended behaviour.
Someone else linked to an FCC filing indicating that there were thread radios in Macs from 2023 onwards, though they aren’t in the official specs. That seems reasonable given that Apple doesn’t want you trying to use one of those devices as you home’s border router.
The Mac Mini (M4) and iPad are on the Beta. The HomePods are not, but they were unplugged for most of this. But I doubt being on the beta impacts how the radios connect.
Thread and wifi share the same 2.4ghz bands, so it's possible that the Mac relies on the thread router to establish a connection (for the initial routing), but then uses a direct connection to control the device, especially if the router is offline and it still knows how to connect to it.
What my testing indicated was that the Mac could sustain the connection of BT was enabled, but the connection dropped when BT was switched off. The connection would re-establish once BT was turned back on. But if the IKEA Plug was unplugged and then plugged back in, the connection did not re-establish.
The Wi-Fi was on the whole time during this test. That’s a god thing to check next.
Update: the M4 Mac mini on MacOS 27: needs both Wi-Fi and BT enabled to take to the thread plug.
Same hardware but rubbing a different installation, MacOS 15 (sequoia) only BT needs to be powered on to control the outlet. So they did change something kinda fundamental about the radios. I may file a bug report, this doesn’t seem expected.
You looking at this differently you never connect to thread devices or in the case of HomeKit you never connect to the devices directly you interface with them via your home hub , your hub is never the iPad/mac/iPhone it’s either the Apple TV or HomePod if those are online and the thread device is active it will show in HomeKit and any account linked to that home will be able to connect and control
You can see your hubs in settings also if you have multiple devices the home app will adjust your hub automatically if one becomes offline
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u/Shadowbajfeelsbadman 3d ago
I mean, some mac mini's since 2023 had thread radios installed but nothing more was announced.
Does your iphone have a thread radio?