Energy monitoring over Matter

A photo of a Meross energy monitoring smart plug in a UK plug socket

Back in April last year, I bought a pair of Meross energy monitoring smart plugs (sponsored link). I’d chosen them because they supported Matter, and so could be easily added to Home Assistant, Google Home and Apple Home all at the same time. However, I lamented that their Matter support was limited to turning them on and off; the energy monitoring data wasn’t available through Matter. That has now changed.

If you have these plugs, or are looking at buying them, here’s how to get energy monitoring over Matter into Home Assistant:

Step 1: Update the Firmware

Firstly, you’ll need to open the Meross app on your phone, and ensure that the smart plug is linked to the app. Next, you’ll need to do a firmware update – this is located on the user tab, for some reason. The firmware update should take a couple of minutes.

A screenshot of the Home Assistant interface, showing the settings for the Meross energy monitoring smart plug and the 're-interview device' option.

Step 2: Re-interview your smart plugs

Originally, the way I found out that this was working was because one of my plugs had stopped working, and needed a factory reset. I then had to remove and re-add it to Home Assistant, Google Home and Apple Home. When I re-added it to Home Assistant, that was when I found that it now supported energy monitoring over Matter, as the power, wattage, voltage and current for the smart plug now appeared in the device settings.

The good news is that you don’t need to remove and re-add the device. Instead, you can ‘re-interview’ the device. Open it up in Home Assistant’s device settings, and then click the three dots next to ‘Share device’, and then ‘Re-interview device’. Home Assistant will then attempt to find out what capabilities the device has, and should add the new entities for you.

Step 3: Uninstall the Meross LAN custom integration

Now that Home Assistant can receive the energy monitoring data over Matter, you shouldn’t need the Meross LAN integration from HACS anymore. You’ll need to amend any existing automations that use the Meross LAN entities (I use this energy monitoring blueprint), and then remove the devices before uninstalling it through HACS. This was one of the integrations that was causing the biggest slowdowns in my Home Assistant, and it seems to be more responsive now that I’ve removed it.

The key advantage of using energy monitoring over Matter is that the data remains local to your home network. Otherwise, you’re sending and receiving data to Meross’ servers (unless you’ve managed to reconfigure them to use a local MQTT broker like Mosquitto). That also means that, if those servers go down or Meross withdraws support, you would no longer get energy monitoring data. Switching to Matter should therefore give your smart home system more resilience.

Meross energy monitoring smart plugs

A photo of a Meross energy monitoring smart plug in a UK plug socket

I’ve recently bought a pair of Meross energy monitoring smart plugs (sponsored link), and by integrating these with Home Assistant, I now get notifications when the washing machine and tumble dryer have finished.

Previously, I’ve used Tuya smart plugs. Which are fine, but these ones don’t do energy monitoring, don’t work with Apple HomeKit and I have some privacy concerns. The Meross plugs, on the other hand, do offer energy monitoring, can be used with 13 Amp devices, and also work with Matter. They’re also smaller, and feel more solidly built than the older Tuya plugs.

Matter support

These smart plugs also support Matter, the open smart home standard. This should mean that you can use them with any smart home ecosystem, whether that’s Amazon, Google, Apple HomeKit, Samsung SmartThings or Home Assistant. I was able to get them to pair with Home Assistant, but not with HomeKit. It turns out I need a device that can act as a HomeKit hub, which can be a permanently plugged-in iPad, Apple TV or Apple HomePod. It won’t just use any other Matter server on my home network. This is ironic as the Home Assistant app uses the same Matter provisioning process on iOS devices.

It’s also worth noting that Matter support is limited to turning the smart plugs on and off. I’m guessing the Matter specification doesn’t include energy monitoring as yet. Also, these smart plugs connect over 2.4 Ghz Wifi, which is worth noting if you’ve configured your Wifi network to only use 5 GHz. They don’t use Thread.

Screenshot of the hassio_appliance-status-monitor Blueprint being configured as an automation in Home Assistant

Making use of energy monitoring

If you want to take advantage of the energy monitoring capabilities of the smart plugs, you’ll either need the official Meross app (for iOS and Android), or use Home Assistant. Whilst I have installed the Meross app, I’ve set up the automations in Home Assistant. There isn’t an official Home Assistant integration for Meross, so you’ll need to install the Meross LAN custom integration which is available through HACS.

Once you’ve set it up and added your devices, you’ll need to set up the energy monitoring automation. By far the easiest way is to use this BlueprintBlueprints are essentially templates for automations that you can download and configure. Make sure you follow the instructions, as you’ll need to create four Helpers for each smart plug, and give them specific names.

You can then define actions to take when the energy monitoring detects the appliance has started and ended. In my case, I’ve told it to send a notification to my phone when the device has finished. In the case of my tumble dryer, this includes a 15 minute delay as it uses less power towards the end (and otherwise results in notification spam). You may need to tweak the power thresholds as well. If all goes well, then you’ll get a notification like the one in the screenshot below.

A screenshot of a notification from Home Assistant stating that the washing machine has finished, triggered by the energy monitoring smart plugs

Doing this means that you can get one of the key features of a smart device, without paying a significant premium. I paid £25 for the two plugs from Amazon, whereas it would have cost at least another £100 to buy a smart tumble dryer. Our washing machine is 9 years old and I’m not even sure that smart washing machines were on the market at the time.