You're sitting on the couch reading. Perfectly still. The lights shut off. You wave your arms like you're hailing a cab in your own living room, because the motion sensor - doing exactly what it was designed to do - can't tell the difference between an empty room and a room with a quiet human in it.
Every smart home owner knows this moment. The Aqara FP300 is the device that finally fixes it, and it does quite a bit more than that.
What Makes mmWave Different
Traditional motion sensors rely on passive infrared - PIR - which detects changes in heat signatures. Walk through a room and PIR picks you up instantly. Sit down and stop moving? You vanish. As far as the sensor knows, the room is empty.
Millimeter-wave radar works differently. Operating at 60GHz, it detects the micro-movements of a living body: the rise and fall of breathing, the subtle shifts of someone reading or working at a desk. The FP300 can hold presence on a stationary person at up to six meters - roughly twenty feet - across a 120-degree field of view. Response time is sub-500ms. That is enough to cover most rooms in a single placement.
What Aqara did with the FP300 is combine both approaches. Their "Infrared Radar Dual Presence" system fires the PIR sensor first for fast entry detection, then the mmWave radar takes over for sustained occupancy. Fast on, accurate hold. Simple idea, but nobody else has executed it this well in a battery-powered package.
Five Sensors, 61 Grams
The FP300 packs five sensors into a housing lighter than a deck of cards: 60GHz mmWave radar, PIR motion, temperature, humidity, and ambient light. Wall mount it, ceiling mount it - no wiring required. Two CR2450 coin cell batteries power it for roughly two years on Thread or up to three years on Zigbee.
That last detail matters. This is the first battery-powered mmWave presence sensor Aqara has made. We've deployed their FP2 extensively, but it requires USB-C power. Excellent sensor - running a cable to the middle of a ceiling just isn't "invisible by design." The FP300 goes wherever you need it.
The ambient light sensor enables lighting automations that respond to actual conditions rather than time-of-day guesses. The temperature and humidity readings - and I'll be upfront, these aren't lab-grade instruments - are more than accurate enough for HVAC automation triggers. Which brings us to why this sensor is particularly relevant if you live where we live.
A Dallas Summer Makes the Case
If you've spent a July in North Texas, you understand HVAC costs in a visceral way. When it's 105 degrees outside, your cooling system is the single largest energy consumer in your home. Most homes cool every room to the same temperature whether anyone is in it or not.
With presence detection, temperature, and humidity data from every room, your system can make intelligent decisions. The upstairs guest bedroom that nobody enters between Monday and Friday? Let it drift. The home office where you spend nine hours a day? Keep it comfortable. The kitchen that spikes in humidity when you cook? Trigger ventilation automatically.
Room-by-room occupancy-based climate control is not a new idea, but achieving it previously required either wired sensors or separate devices for presence and climate monitoring. The FP300 consolidates it into a single battery-powered package for $49.99.
During our humid months - anyone who has stepped outside in August knows exactly what I mean - the humidity sensing adds a useful dimension. Humidity-aware ventilation decisions can prevent that clammy feeling that makes 76 degrees feel like 82, and they reduce the load on your system by addressing moisture before simply cranking the thermostat lower. Pair these sensors with automated solar shading and the cumulative energy savings become hard to ignore.
Thread, Zigbee, and an Honest Assessment
The FP300 supports two protocols: Thread (with Matter) and Zigbee 3.0. You switch between them via Bluetooth, no hub required for the switch itself. The flexibility is welcome, but the choice matters more than you might expect.
In Thread mode, the FP300 operates as a Sleepy End Device, which means it does not extend your Thread mesh network. It connects, it reports, but it does not help other devices. That is a reasonable trade-off for battery life, but worth knowing if you are counting on every device to strengthen your mesh.
More significantly, Thread and Matter mode currently offer limited configuration options. Sensitivity adjustments, detection range tuning, mode selection - the granular controls that let you dial in the sensor for a specific room - are constrained in Thread mode.
Zigbee mode, paired with Zigbee2MQTT, is where the FP300 opens up. Full configurability. Sensitivity, range, detection modes - everything is exposed and adjustable. For a home where the goal is precise, room-specific automation, this matters.
Our recommendation, and the way we deploy these: Zigbee mode through Zigbee2MQTT, running entirely on local processing. No cloud dependency, no data leaving the home, full control over every parameter. It aligns with how we think smart homes should work.
Against the Competition
The sensor market has options, but the FP300 occupies a position none of them quite match.
The Eve Motion at $39.95 is a solid PIR sensor, but PIR only - so you are back to waving your arms on the couch. The Aqara FP2 at $59.99 offers multi-zone mmWave detection with more advanced spatial awareness, but it requires wired power. The Eve Room at $99.95 monitors temperature, humidity, and air quality, yet has no presence detection at all.
The FP300 is the first device to credibly combine presence detection and climate monitoring in a battery-powered, wireless form factor. At $49.99, it costs less than any of those alternatives except the PIR-only Eve Motion, and it does substantially more.
On false triggers - the concern that haunts every presence sensor - testing from SmartHomeScene's teardown and our own deployments confirms zero false triggers from pets, ceiling fans, and HVAC airflow. BGR called it "the only smart home sensor you need." Trusted Reviews described it as a "truly wireless mmWave presence sensor that actually works." That emphasis on "actually works" says something about the state of this product category up to now.
The Bigger Picture
A single FP300 is a nice upgrade. A home with eight or ten of them, feeding data into a well-designed automation system, is something else entirely. Lights that respond to your actual presence in every room. Climate that follows you through the house. Security that reacts to real occupancy rather than schedules. All of it running locally, all of it invisible.
That's the kind of integration we build at Varavivo - systems where the technology disappears and the home just responds. If you're curious what occupancy-aware automation would look like in your home, or you're tired of waving at your ceiling, we're always happy to talk it through.