Sonoff Zigbee and Thread/Matter dongle

A photo of the Sonoff ZBDongle E which offers Zigbee and Thread support

If you’re a Home Assistant user, and want to connect your Zigbee and Matter devices, then one option to consider is this Sonoff ZBDongle E. I bought one a couple of weeks ago, and it seems to work fine with my Home Assistant setup.

One thing you will notice if you view its Amazon product page (sponsored link) is that there’s no mention anywhere of Thread or Matter. Out of the box, this Sonoff dongle will only work with Zigbee devices. However, if you follow this handy guide from Smart Home Scene, you can flash the dongle with custom firmware, which adds support for Thread as well. As I mentioned in my recent is there a Zigbee network in your house blog post, both Zigbee and Thread are protocols in the 802.15 family.

The firmware flasher is actually browser-based, and so there’s no need to download additional software. However, it’ll only work in Edge or Chrome, as seemingly Firefox doesn’t have away of allowing web pages to access serial ports.

Note that the guide linked above is for Home Assistant Supervised and OS. If you’re running Home Assistant as a Docker Container, then you’ll need to install this Docker Image as well. I haven’t tried it myself, as I run Home Assistant Supervised, but this seems to be the way to get it to work.

Once it’s all set up, you’ll be able to add both Zigbee and Matter devices to your Home Assistant installation.

The Sonoff dongle cost £22 when I bought it earlier this month, although at the time of writing the price has been hoicked up to £30. That makes it only £1 cheaper than the Home Assistant Skyconnect, which is the official dongle. Therefore, my recommendation of the Sonoff dongle being a cheaper option no longer applies and it’s up to you which one to buy.

Is there a Zigbee network in your house?

A photo of our Smart Meter which states it is Zigbee certified

If you’re in the UK, and have a smart meter, then your home probably has a Zigbee network that you may not know about.

What is Zigbee?

Zigbee is a wireless mesh networking protocol, that is commonly used for smart devices. If you have smart lightbulbs, such as the Ikea Trådfri or Philips HUE range (sponsored link), then Zigbee is what these devices use to communicate with their hub.

Zigbee isn’t the same as Wifi. Wifi devices belong to the 802.11 family of IEEE standards, whereas Zigbee is in the 802.15 family . There’s a difference at the hardware level, so a device that supports Wifi can’t use Zigbee unless it has a specialised chipset. However, there is commonality between the two; like Wifi, Zigbee uses IP addresses, and operates on the 2.4 GHz band.

Our In Home Display, which shows our usage from our smart meters and connects using Zigbee

If you have smart meters for your electricity and gas, then these will use Zigbee to communicate with your IHD (In Home Display). This is the small device that shows your current and daily usage.

Can you access this Zigbee network?

No. Even if you have a device with Home Assistant and a Zigbee dongle, it won’t be able to see the Zigbee network that your meters and IHD use. I suspect this is because your electricity meter has its own SIM card, to access the internet to send your readings. If you could access this Zigbee network, then it may use your electricity meter’s internet connection and not your own.

There are, however, some devices that will bridge between this Zigbee network and your own Wifi network at home. Some newer IHD devices offer this, and if you’re an Octopus Energy customer, you can join the waiting list for the Octopus Home Mini. I joined the waiting list a few months ago, but I haven’t heard anything yet. Meanwhile, you can also buy a Glow CAD (Consumer Access Device) for £65, which can connect to Home Assistant. Alas, it’s out of stock at the time of writing.

Another option for Octopus Energy customers is this Home Assistant addon, which brings in your usage data. However, it updates half hourly unless you already have an Octopus Home Mini.

Other ‘secret’ networks in your home

In our home, we also have a couple of Thread networks. Thread is related to Zigbee in that it’s also in the 802.15 family, and is arguably a successor. Nest developed it to enable their smart thermostats to talk wirelessly to the heat link that connects to your boiler, so this makes one network. Newer Nest thermostats can act as a Thread Border Router and so other devices using Matter can connect to it, but we have an older model.

We also have a pair of Google Nest Wifi devices (a hub and a point) which use Thread to communicate with each other. Google has updated these to offer a Thread Border Router, and so I’ve been able to access this with Home Assistant, ready for when we have some Matter compatible devices. So at least I can access one of the three non-wifi networks in my home.

Further reading

Whilst researching this, I came across this Hacking Your Smart Meter (Part 1) article, although there doesn’t appear to be a part 2. Instead, the author, Terence Eden, uses an API from his energy company as above.

The Smart Meter Home Area Network is also a really useful article, on what is quite a well balanced web site about the various pros and cons of having a smart meter. Because we export excess energy from our solar panels, we need to have a smart meter to be paid back for what we export.