Motion sensors detect movement; presence sensors detect a still person in a room — and mixing them up is the most common automation complaint.
This category covers two genuinely different technologies that get marketed under overlapping names. A PIR motion sensor (passive infrared) detects a change in heat as something moves across its field of view — cheap, reliable, battery-friendly, and the right choice for a hallway light or a security automation. It goes blind the moment you sit still, which is exactly why it turns bedroom and office lights off while someone is still in the room.
An mmWave presence sensor uses radar to detect a person's presence, including a still, breathing body with no visible movement — solving PIR's biggest weakness. It's the right technology for a room where lights turning off on someone sitting still is the actual complaint, like a home office or a living room during a film.
The two are not simply better-and-worse versions of each other: PIR uses a fraction of the power (important for a battery sensor covering a whole hallway network) and mmWave can occasionally false-trigger on a moving fan, curtain, or even a pet, depending on sensitivity tuning.
What to look for
PIR vs mmWave, matched to the room
Use PIR for hallways, stairs, garages, outdoor lighting and anywhere brief movement is the actual trigger you want. Use mmWave presence sensing for offices, living rooms, and bedrooms where a still, seated or sleeping person should keep the lights or climate control active.
Detection range and field of view
Manufacturer range figures (often 5–9 metres) assume a clear, direct line of sight; furniture, doorframes and mounting angle all reduce effective range. Check the field-of-view angle too — a narrow cone misses activity to the side of the sensor entirely.
Sensitivity tuning and false triggers
mmWave sensors can pick up a moving ceiling fan, a curtain in a draught, or a pet as presence. Better models offer adjustable sensitivity zones or exclusion areas in their app; check for this if the room has one of these known trigger sources.
Many current motion and presence sensors bundle a light-level sensor as standard, letting an automation trigger only when it's actually dark rather than during daylight. Some higher-end models add temperature and humidity too, which can replace a separate climate sensor in that room.
Mains-powered vs battery
Mains-powered sensors (common for mmWave, which draws more continuously) skip battery management entirely if there's a nearby socket or a ceiling rose to wire into. Battery PIR sensors last many months to a couple of years depending on traffic and reporting frequency.
Mounting and field placement
Ceiling-mounted units generally give the most even room coverage for presence sensing; corner or wall-mounted PIR units are standard for hallway and security use. Check the included mounting hardware matches where you actually intend to fit it.
The shortlist compared
Brand
Model
Type
Protocol
Mains or battery
Indicative price
Aqara
Motion Sensor P1
PIR
Zigbee
Battery
€20
IKEA
VALLHORN
PIR
Zigbee
Battery
€12
Philips Hue
Motion Sensor
PIR
Zigbee
Battery
€40
Aqara
FP2
mmWave presence
Wi-Fi (local)
Mains
€70
Everything Presence
One
mmWave presence + PIR
Wi-Fi / ESPHome
Mains
€70
SONOFF
SNZB-06P
mmWave presence
Zigbee
Mains (USB)
€18
Prices move constantly and vary by country, so we give an indicative band
rather than a figure that would be stale within a month. Check the brand's own store for the
current price.
The picks in detail
Aqara Motion Sensor P1
Zigbee (PIR)
Aqara's P1 is a well-rounded, battery-efficient PIR sensor with a genuinely wide field of view and a bundled light-level sensor, making it a solid all-round default for hallways, stairs and entryways in a Zigbee household.
As a PIR device it shares the category's fundamental limitation: it goes blind the instant motion stops, so it's the wrong tool for a room where someone sitting still should keep the lights on.
Wide field of view for a PIR sensor
Bundled light-level sensing for daylight-aware automations
Long battery life
Cannot detect a still person, by design of the PIR technology
Zigbee only, no Wi-Fi/Matter variant
IKEA VALLHORN
Zigbee (PIR)
IKEA's motion sensor is the budget default for scattering several around a home cheaply, and it integrates reliably with Zigbee hubs including IKEA's own DIRIGERA.
Detection range and field of view are noticeably narrower than Aqara's or Philips Hue's equivalents, which matters more in larger rooms or long hallways than in a small space.
Cheapest reliable PIR sensor here
Simple, dependable Zigbee pairing
Good for scattering several around cheaply
Narrower detection range and field of view than pricier alternatives
Basic feature set, no bundled temperature sensing
Philips Hue Motion Sensor
Zigbee (PIR)
Hue's sensor bundles temperature alongside motion and light level, and integrates especially smoothly if you're already running Hue lighting, with per-room sensitivity and timeout settings in the Hue app.
It's the priciest PIR sensor in this comparison, and the extra cost buys polish and Hue-specific integration rather than a fundamentally different detection technology.
Bundles temperature, light level and motion in one unit
Very smooth integration with Hue lighting specifically
Reliable, mature hardware
Most expensive PIR sensor here
Less compelling value outside a Hue-centric setup
Aqara FP2
Wi-Fi, local processing (mmWave presence)
The FP2 is a genuinely capable mmWave presence sensor that can define multiple detection zones from a single unit and distinguish between them, useful for a large open-plan room where you want different behaviour near the sofa versus near the door.
It processes locally on-device rather than depending on cloud inference, which is a meaningful privacy and reliability advantage over some competing presence sensors, and it needs mains power given the continuous radar operation.
Multiple zone detection from one sensor
Local on-device processing, not cloud-dependent
Reliable presence detection for seated/still people
Needs mains power, can't be placed anywhere battery-only can
Setup and zone configuration has a learning curve
Everything Presence One
Wi-Fi / ESPHome (mmWave + PIR combined)
A favourite in the Home Assistant community, this open-source-friendly sensor combines mmWave presence with a PIR sensor and a light/temperature/humidity bundle in one unit, running on ESPHome firmware for fully local, highly configurable automation logic.
It rewards someone comfortable with Home Assistant and ESPHome configuration rather than a simple app; less technical households will find the setup considerably more involved than the Aqara or SONOFF alternatives.
Combines mmWave and PIR in one sensor for the best of both
Fully local via ESPHome, highly configurable
Bundles light, temperature and humidity
Setup and configuration needs Home Assistant/ESPHome comfort
Smaller company, less mainstream app polish
SONOFF SNZB-06P
Zigbee (mmWave presence)
SONOFF's presence sensor undercuts the FP2 and Everything Presence One considerably on price while still using genuine mmWave detection over Zigbee rather than PIR, making it the accessible entry point into presence sensing for an existing Zigbee household.
Zone configuration and sensitivity tuning are more basic than the pricier alternatives, and it's powered over USB rather than battery, so it needs a nearby socket.
Cheapest genuine mmWave presence sensor here
Native Zigbee, easy hub integration
USB-powered, no battery to manage
Less configurable than Aqara FP2 or Everything Presence One
What's the actual difference between motion and presence sensors?
A motion (PIR) sensor detects movement and goes blind the instant something stops moving. A presence (mmWave) sensor uses radar and can detect a still, breathing person with no visible movement, which is what solves the 'lights turn off while I'm sitting still' complaint.
Why do my lights turn off while I'm sitting at my desk?
Almost certainly because the sensor triggering them is PIR-based motion detection, not presence detection. Swapping that specific sensor for an mmWave presence sensor is the fix, rather than just increasing the timeout, which only delays the same problem.
Can mmWave sensors see through walls or doors?
To a limited degree — radar can sometimes pick up movement through a thin interior wall or a door, which can cause false triggers in an adjacent room. Placement and, where available, zone/sensitivity configuration in the app usually resolve this.
Do presence sensors need mains power?
Almost always, because continuous radar sensing draws meaningfully more power than a PIR sensor's occasional detection burst. A small number of Zigbee mmWave sensors run on USB power rather than a fixed mains connection, but true battery-only mmWave presence sensors are rare.
What causes false triggers on mmWave sensors?
Moving ceiling fans, curtains in a draught, and pets are the most common causes, since radar detects any motion including small or repetitive movement. Adjustable sensitivity and exclusion zones, where the model offers them, are the fix.
Terms explained
PIR (passive infrared)
A sensor technology that detects a change in infrared heat signature as an object moves across its field of view; cheap and battery-efficient, but blind to a stationary object.
mmWave (millimetre-wave radar)
A sensor technology that uses radar to detect motion and presence, including a still, breathing person, at the cost of higher power draw and occasional false triggers on fans or repetitive motion.
Field of view
The angular range a sensor can detect within, typically stated in degrees; a narrower field of view misses activity outside that cone even within stated range.
ESPHome
Open-source firmware for ESP32/ESP8266-based devices that runs fully locally and integrates natively with Home Assistant, popular for DIY and enthusiast sensor builds.
