Sonoff's new Matter-over-Wi-Fi presence sensor undercuts the field at $24.90

Sonoff quietly put a new presence sensor on its own store in late October: the SenseGuard Presence Core, a 24GHz radar sensor that runs over Wi-Fi and Matter instead of Zigbee, for $24.90. I don’t own one, and this is a research piece, written from Sonoff’s own product listing rather than a test in my house.

Short version: at $24.90 this undercuts every finished mmWave presence sensor on my picks page, which ran $37.99 to $92 on October 26. It is also new enough, and thinly enough documented, that I’m not recommending it yet. Sonoff’s page says it reaches Home Assistant two ways: a standard Matter connection, which Home Assistant already knows how to turn into an occupancy sensor, or WebSocket, MQTT and “open APIs.” It also ships a browser-based local console for settings Matter doesn’t expose. What Sonoff’s page doesn’t say is whether setup needs the eWeLink app or account, what powers the thing, or whether anyone outside Sonoff has gotten one working. Watch this one before buying it.

What was announced

Two things worth flagging before the specs above sink in. First, there is no Amazon listing for this exact SKU that I could find, so “price” here means Sonoff’s direct price, not a US retail price with the usual Prime-exclusive discount I track for other sensors. Second, the listing gives no power source at all. Every other wired mmWave sensor on my picks page runs off USB; I’m not assuming this one does the same without Sonoff saying so.

Sonoff also sells a second, separate SKU with almost the same name: the SenseGuard Presence Core 24GHz Zigbee sensor, SNZB-06P24, at the same $24.90. Its own page describes it as a Zigbee router with no mention of Matter, Bluetooth, a coordinator or a bridge anywhere in the text. These are two different products built for two different radios, sold side by side at the same price. If you’re shopping Sonoff’s site, check the SKU before you click buy.

What stays local, what doesn’t

The Matter path

Sonoff’s page says the sensor “supports Matter” for Apple Home and SmartThings. On the Home Assistant side, this isn’t a case of waiting for new code: Home Assistant’s own Matter integration already maps the standard Matter occupancy-sensing cluster to an occupancy sensor entity, the same generic path any Matter occupancy device uses. If the SenseGuard Presence Core exposes a standard Matter occupancy cluster, as Sonoff’s page implies, Home Assistant should see it as an occupancy sensor with no custom integration required. I’m phrasing that as “should,” not “does,” because nobody has paired one yet in anything I could find.

The open-API path, and the console

Past the Matter claim, Sonoff’s page says the sensor also talks WebSocket, MQTT and “open APIs” for Home Assistant and openHAB, separately from the Matter connection. That’s a second local-ish route into Home Assistant, and it’s the more interesting one for a Home Assistant house, since it would let you read zone-level data Matter’s generic occupancy cluster doesn’t carry. I say “would” because I found no documentation of the actual MQTT topics or API shape, and no one has reported using it.

The local web console is a local-first detail worth noting: a browser page served from the device itself, on your own network, for firmware updates, light-level calibration and logs. That’s exactly the kind of feature I pay attention to, because Matter’s occupancy cluster doesn’t expose calibration controls, so without a local console you’d be stuck with whatever the factory settings do. Whether reaching that console, or the sensor’s first Matter pairing, needs the eWeLink app or a Sonoff account first is the one thing I most wanted to confirm and couldn’t. Most other Sonoff Matter products pair through eWeLink before they’re handed to a Matter controller; nothing on this product’s own page says that’s true here, and nothing says it isn’t.

What isn’t addressed

Power source is the other open question. Every USB-powered mmWave sensor on my picks page states that plainly on its own product page; this one doesn’t say battery, USB or mains anywhere.

Buy, wait or ignore

Home Assistant house. Wait. The price is real and the Matter path has a generic, already-built landing spot in Home Assistant, but there’s no confirmation anyone has actually paired one, no documented MQTT schema, and no answer on the eWeLink question. I’d rather see a forum thread or a teardown first.

Apple or Google Home house. Wait for the same reason. Sonoff’s own page names Apple Home and SmartThings as Matter partners, but that’s a vendor claim with no third-party pairing report behind it yet.

Budget buyer. This is the cheapest finished 24GHz presence sensor I’ve seen for Home Assistant, full stop, and that alone makes it worth watching. I wouldn’t buy the first batch of a brand-new SKU with this many open questions, especially with no return-friendly US retail listing yet. Give it a few weeks.

Does this change my picks?

Not yet.

• Best mmWave presence sensors for Home Assistant. No pick changes. If independent testing confirms the Matter and MQTT claims, and someone answers the eWeLink and power questions, this becomes a serious budget contender against the Aqara FP1E and the Everything Presence Lite. Until then it’s a sensor to watch, not a sensor to buy.