I set up my first Matter device today. I bought an Aqara U200 lock. It’s really good and I set it up in no time.
However, when it came to connecting it to HA via Matter over Thread, I started to get a bit confused and dissapointed.
I have an Amazon Echo 4. I hoped that HA would be able to use this as a Thread Border Router (TBR) to talk to the lock.
When I tried to add the lock using the HA Companion App (Android) it told me that I don’t have a TBR. But, in Settings → Devices and Services → Integrations → Thread → Configuration it shows my Echo device. This is listed under Other Networks. After lots of reading I couldn’t see how to use this directly as a TBA for HA.
What I did in the end was to add the lock directly to Amazon Alexa, and then use the Alexa app to allow connection from another system, using the Other Assistants and Apps option within the settings of the lock device.
I was then able to connect to the lock to HA, in the HA Companion App, by chosing the option that says ‘it’s [the lock] already in use’.
Is this the only way to attach a Matter device to HA using an Echo as a TBA? I was expecting HA to be able to control the Echo TBA to pick up devices directly - without adding them to Alexa first.
Alexa TBR has its own Thread network, and HA OTBR has its own Thread network. HA OTBR has a way to make its Thread network the same as some other Thread network (this is called the preferred network). For HA OTBR to make its Thread network the same as Alexa’s, one somehow has to get the Thread dataset/credentials from Alexa and get it imported/synch’d into HA. This may not be so easy to do.
So assuming there is only one Thread network (Alexa’s Thread network), then yes you’ll have to use the Alexa App (which will know the Alexa Thread dataset/credentials) to get a device to join the Thread network … and it will also add it to Alexa’s Matter Controller/Fabric. Once added to a Matter Controller/Fabric, then the only way for HA to control the device is to get Alexa’s Matter Controller/Fabric to “share” it with HA’s Matter Controller/Fabric (which will be different than Alexa’s Fabric) which is what you did.
Like WiFi, Thread networks require security credentials to connect. HA is showing you “discovered” Thread networks, not necessarily networks you can use, kind of like you can see nearby WiFi hotspots but can only join if you know the password. If HA has the credentials for the network it displays a tiny [i] (circled “i”) icon next to the name; admittedly this could be better presented to the end-user.
Unfortunately unlike WiFi, most vendors that make Thread Border Routers have chosen to hide the credentials from you, the owner of the device, and make them super-secret so that only apps compatible with that vendor have access to the credentials, which is why you are required to use their app for commissioning new devices.
It is currently the best way. Once the device is part of the HA Matter fabric, I believe you can safely remove it from the Alexa Matter fabric without any impact.
If you could somehow extract the secret Thread credentials from your Echo 4 and enter them into Home Assistant to get the [i] icon, then (after a few more one-time-only steps) you can use the HA companion app to directly commission new devices onto the Echo 4 Thread mesh and skip the intermediate step requiring the Alexa app. A quick search didn’t turn up readily-available procedure for this, but you might be able to find someone who’s gotten this working.
Thread protocol version 1.4, which was just recently approved, includes a new standards-based method of sharing credentials between different vendors’ networks/apps, so hopefully within a year or two, once all the TBRs are upgraded, this problem will resolve itself. Hopefully.