Home Assistant SkyConnect (Home Assistant Connect ZBT-1) - official Zigbee and/or Thread USB radio dongle from Nabu Casa

FYI, Nabu Casa’s Zack Barett has announced on Twitter that Home Assistant founders are planning on releasing an official Home Assistant SkyConnect USB Stick (ie. a physical radio adapter/dongle hardware that is used to control compatible wireless devices via integrations they officially support).

Order it here → https://www.home-assistant.io/skyconnect/

Documentation → https://skyconnect.home-assistant.io/

It will initially support controlling Zigbee 3.0 devices (as well as most other Zigbee devices), and then later they plan on updating the firmware for it to also support controller Thread/OpenThread devices via other integrations/add-ons, and that will hopefully also include integrations/add-ons for nativly supporting for upcoming Thread devices that uses the Matter standard too.

Nabu Casa electronics engineer developer (and Home Assistant developer) agners is leading the hardware design of the circuit board and firmware development for this USB RF-radio hardware.

It is designed for direct attachment via a USB port and will be based on a Silicon Labs EFR32MG21 SoC that has an IEEE 802.15.4 multi-protocol 2.4GHz radio MCU that is on paper capable of concurrently running both Zigbee 3.0 (Silabs EmberZNet/EZSP) and Thread (Silicon Labs OpenThread/Spinel, which indirectly includes support for Matter/CHIP over Thread) stacks/protocols at the same time by using firmware in what is called RCP (Radio Co-Processor) Multi-PAN mode to enable simultaneous multiprotocol support. Direct local serial communication will be done via an onboard USB-to-UART bridge/converter CP210x series VCP (Virtual Com Port) chip from Silicon Labs, however, if and when the radio is running RCP Multi-PAN firmware the host also needs to run each network protocol stacks a daemon/service which the application communicates with through TCP/IP.


Be sure to fill out Home Assistant SkyConnect interest form so they know how many they should make:


Again, this radio USB dongle hardware adapter is based on the EFR32MG21 SoC/MCU same chip that is onboard the Home Assistant Yellow (formerly Home Assistant Amber) all-in-one embedded computer appliance, although rather than a board built from scratch like this Home Assistant SkyConnect USB Stick the adapter inside the Home Assistant Yellow uses an Silabs MGM210P radio board (which in turn is a pre-certified RF module that contains the combination of an EFR32MG21 SoC and an onboard Ceramic Chip Antenna as its core components + will use a different firmware as GPIO pinout are not the same as the Home Assistant SkyConnect USB Stick dongle/adapter).

Official stable and beta firmware releases look to be able here from Nabu Casa:


Home Assistant / Nabu Casa developer agners are also working on several add-ons that will also allow both these adapers to concurrently as Zigbee Coordinator and as an OpenThread Border Router (OTBR) for Thread-based Matter/CHIP-compatible devices (communicating locally over a USB-to-serial port using OpenThread RPC Spinel interface over UART. Silabs EmberZNet EZSP interfaces for Zigbee via the zigpy libraries will also enable support to the ZHA (Zigbee Home Automation) integration out-of-the-box.







There’s also ZHA/zigpy development discussions about Zigbee and Thread adapter compatibility here:


PS: EFR32MG21 is by the way the same Silabs radio MCU SoC radio chip used in "ITead Sonoff Zigbee 3.0 USB Dongle Plus V2” (model “ZBDongle-E”) and their previous ITead Zigbee 3.0 USB Dongle (Model: 9888010100045). More information about those competing and possibly compatible adapters here:




@agners While this first-generation Home Assistant SkyConnect USB Stick has not yet even been released I would personally still very much like to suggest/request that Z-Wave Controller support is also considered for the next-generation of Home Assistant SkyConnect USB Stick hardware (e.g. “Home Assistant SkyConnect 2 USB Stick” if you will). Especially if Nabu Casa is aiming to get a Z-Wave Certification for Home Assistant with the Z-Wave JS integration as recently mentioned a few times.

Such a next-generation Thread + Zigbee + Z-Wave combination all-in-one dongle would be a great spiritual successor to the still popular Nortek GoControl QuickStick Combo Model HUSBZB-1 (which has a Silabs Z-Wave 500 chip + a Silabs Ember 3581 Zigbee chip inside it) and would make it an more universal RF radio dongle. I think Nabu Case could even sell such an as a White-Label product to other open-source home automation projects (such as for example OpenHAB, Domoticz, ioBroker, Hubitat, and Jeedom) for them to rebrand it and offer their own support when used with their platforms, even if only to potentially gain cost advantages from economies of scale when manufatcuring more of them.

Maybe also add an EFR32BG24 chip for Bluetooth Low Energy 5.3 (BLE) with Bluetooth Mesh support?


Anyway, my reasoning for requesting Z-Wave 700/800 support too is that Z-Wave 300/500 series devices are widely available + new Z-Wave 700/800 series devices are just now starting to be released, and as Z-Wave controllers are backwards-compatible many end-users who already have an established Z-Wave network mesh are likely to soon want to upgrade from a Z-Wave 500 series controller to a newer Z-Wave 700 or 800 series controller to be able to use all long-range and battery-life features/functions of latest devices while still being able to take advantage of their Z-Wave mesh network.

Silicon Labs has released EFR32ZG23 (ZG23) SoCs and ZGM230S modules for Z-Wave 800 series:



PS: Might then also be a good idea to upgrade to the newer EFR32MG24 chip for Thread and Zigbee?


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Adding Z-Wave makes the project quite a bit more challenging, as multi-radio certification is quite a bit more challenging.

What is the advantage? From what I understand it has the same RF frontend, its just a bit more powerful which is necessary for Matter device (which we are not). The chip is fairly new, and typically volume availability is worse with new products. It probably would only delay SkyConnect.

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@agners Have you considered making a separate Z-Wave 800 series “Z-Wave Plus LR” dongle?

I do not believe that there are any other Z-Wave 800 series USB dongles on the market as of yet(?).

I do not think there are even any Z-Wave Long Range 700 series (Z-Wave LR 700) dongles for sale(?).

I understand that the Z-Wave LR specification is managed and certified under the Z-Wave Plus V2 certification program that currently mandates the inclusion of the enhanced S2 security framework as well as Z-Wave SmartStart plug-and-play setup feature for the consumer smart home, both of which the Z-Wave JS integration already support.



I know EFR32MG24 is not available at volume yet, so I only meant if you would ever consider making a next-generation of “Home Assistant SkyConnect 2 USB Stick” with Z-Wave support within a few years or so then I think it would probably make the most sense to try to use newer components for all protocols just to make it more future-proof. From a marketing point-of-view it usually helps sales to use the “very latest and greatest” components if available even if do not affect performance. From a supply chain point-of-view one would also think that older components will have earlier end-of-sale and end-of-life.

FYI, ITead has now also released a new Zigbee dongle based on the same EFR32MG21 SoC:


I for one cannot wait to order this stick. Since I have switched away entirely from Z-wave to Zigbee my sensor network has been endlessly more stable and reliable. Adding Thread support would be great for my future-proofing.

Thanks for all the efforts so far!

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Me too, any news on when will this dongle be available?

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Microsoft had problems with the name sky In the UK.

Remember SkyDrive anyone

Doubt that will be an issue when just selling a physical radio USB adapter, (and not any digital service).

Got to admit though that I don’t fully get “sky” reference for this USB adapter as that is usually used for satellite stuff, I think instead “air” is more commonly used for radio stuff, as in reference to “over-the-air”.

I believe “Home Assistant AirConnect” would be better, and use “Dongle” or “Adapter” instead of “Stick”.

I think “Home Assistant AirConnect USB Radio Dongle” would make most marketing sense to me :smiley:

Yeah but SkyConnect is the name of there broadband services including devices.

Yeah definitely agree on adapter think stick implies a full device Ie fire stick

From my experience, “USB stick” or “USB key” also commonly refers to USB flash drives, while “USB dongle” is usually used when talking about USB wireless radio dongles for example Bluetooth and Wi-Fi that connects to a computer to extend functionality, and “USB adapter” is normally used when referring to adapters that convert ports to handle different types of connectors (such as DVI to HDMI or USB to serial port adapters).

That is basically what Wikipedia has to say in its article on “Dongle” today:


Any idea how the SkyConnect will stack up against the ConBee 2 which has a strong signal range via power-amplifier (and if Conbee 2 will be updated to handle Matter)?

I don’t think the Conbee 2 has the necessary hardware to be upgraded to support Thread (it’s not matter, because matter sits on TOP of the networking protocol.)

ConBee II and RaspBee II are based on the older ATSAMR21B18 by Microchip Technology so at least on paper the newer EFR32MG21 SoC (radio MCU chip) hardware from Silicon Labs kicks their a** in every datasheet specification category, see:


Compare CPU, RAM/Memory, Flash/Storage, radio (Receive Sensitivity, Output Power in dBm, RX and TX mA, etc.), etc. specifications, etc. and so on between EFR32MG21 and ATSAMR21B18 SoC radios.

It should however be noted that Silabs has since then also released the even newer EFR32MG24 and while it not make a better dedicated single protocol radio it probably make a better multi-protocol radio.

Other than migrating from Conbee/Raspbee that is really an off-topic discussion in this specific thread, but FYI, ATSAMR21B18 does not support a Thread protocol stack like OpenThread so Conbee II (and RaspBee II) will therefore for sure never be officially updated to support the Thread wireless protocol, however, earlier this year I did read that comment somewhere from Phoscon/Dresden-Elektronik lead developer that their company are working on the development of ConBee III / ConBee 3 Zigbee Coordinator, (though there was no mention if that will also support Thread/OpenThread as well or not, though I would be a little bit surprised if they at least not choose to go with a radio SoC hardware that has multi-protocol support to try to make the hardware of their new product a little more future-proof just in case).

Anyway, long follow-up answer there is; if Phoscon/Dresden-Elektronik, or someone else, makes a competing Thread USB adapter then it should or at least could in theory be compatible with Home Assistant’s upcoming Thread/Matter integration as long as it comes with OpenThread firmware with Spinel + HDLC-Lite over UART protocol support, see discussion here → https://github.com/home-assistant/addons-development/issues/38


Apricate your informative answer. Then Ill await the HA SkyConnect, may it come ASAP!

FYI, while this official Home Assistant SkyConnect USB Stick will probably be an excellent option for early adopters that just want to buy a few of the upcoming devices using the new upcoming Matter (Project CHIP) standard over the Thread protocol as well as those casual users (non-power users) that are sure that they will never connect loads of Zigbee devices (100+) to this single radio adapter, potential buyers should still probably be made aware in advance before buying that this official Home Assistant SkyConnect USB Stick on paper in a multi-protocol setup configured to concurrently use both Zigbee and Thread protocols over the same radio with a large Zigbee network (100+ devices) as well as several Thread/Matter devices will probably not get as good as performance as simply using a dedicated Zigbee USB adapter with a large Zigbee network and then just using this official Home Assistant SkyConnect USB Stick as a dedicated adapter for Thread/Matter only.

That is, when using multiple wireless protocols at the same time on a single radio chip as a multi-protocol adapter this risk becoming a “Jack of all trades, master of none” product, as on paper today, no existing single multiprotocol radio SoC using Matter/CHIP over Thread in combination with Zigbee at the same time should be able to perform as optimal as simply using separate dedicated radio adapters for each wireless protocol. This is totally understandable considering that it will need to handle the work of two radios, even with the protocol stack being off-loaded from the adapter’s MCU to the Host System CPU. The point remains that by using dedicated coordinator/controller radio adapters for each protocol today you are more likely to get the best performance for each protocol if that is what you are looking for. (This fact may of course change in the future over time with newer radio technologies + improved radio time management frameworks and protocol stacks from radio chip manufacturers).

Thus if you plan on potentially using it with a lot of Zigbee devices (like 100+ Zigbee devices) then I would recommend not waiting and instead just buying a separate dedicated Zigbee USB adapter today, then I still recommend you buy this official Home Assistant SkyConnect USB Stick when it becomes available but just use it as a dedicated adapter for only Thread/Matter, or alternatively wait and buy two of these official Home Assistant SkyConnect USB Sticks and use them separately as two dedicated single-protocol radio adapters for the different wireless protocols. As with existing Zigbee USB adapters being good as they already are no need to wait for an all-in-one multiprotocol combination adapter if you plan on building a large Zigbee network when a multiprotocol is likely to not perform as well, (again, on paper at least).

Anyway, suggest users who think they might connect 100+ Zigbee devices someday should consider just buying a separate dedicated Zigbee adapter now to use only for Zigbee devices. Most such dedicated Zigbee adapters should not become e-waste because it will probably be possible to migrate your Zigbee network to a new Zigbee adapter and then most modern dedicated Zigbee adapters can usually be flashed with alternative Zigbee Router firmware and repurposed as a Zigbee Router device (Zigbee network mesh signal repeater). Regardless, you will normally want many good always-on Zigbee Router devices in your Zigbee network mesh to achieve the best possible stable Zigbee environment.

Refrence agners and grobasoz comments → https://github.com/grobasoz/zigbee-firmware/issues/27

grobasoz comment: “Now to the big issue I have with Multiprotocol - and my personal opinion only. A “normal” Zigbee Coordinator on a “significant” network (ie 100+ devices) actually spends quite a bit of radio time managing the network, let alone handling the device messaging.

agners reply: “Agreed, I think the multiprotocol solution might not be for large networks. A person with that many devices, likely will have multiple coordinator/border router capable 802.15.4 radios in the house already :sweat_smile: It is mainly a good solution for new users: People don’t have to choose between Thread and Zigbee at the start, they can mix and match. For power users Thread and Zigbee networks on separate channels definitely make sense (along with dedicated radios). That said, I like the concept of having a rather dumb radio and most of the protocol on the host. So it still might make sense to have the (Multi-)PAN firmware running along with zigbeed on the host. We’ll see how well that works in practice.

PS: Personally I will buy at least two of these official Home Assistant SkyConnect USB Sticks myself and only use one protocol per adapter just to sponsor the Home Assistant founders and Nabu Casa.


Does anyone know if it is possible to turn off zigbee and just have thread on SkyConnect? I already have my zigbee network working perfectly so I am not keen on introducing another zigbee signal into the mix.

I plan on substiututing my current zigbee stick, with this one

That will certenly be possible by simply not using it for Zigbee and then it will use activate the Zigbee part for it.

I read now however that they will initially only ship it with Zigbee support, and that Thread support will come later via firmware and software updates.

That is how I plan on using one, though I am planing on buying two and using one dedicated for Zigbee and one dedicated for Thread.

I’ve not used a multi protocol stick so I’m not sure what the capabilities are. I’ll wait and see I guess.