Presence and motion sensors: which fits your automation?

Choose the sensor around what should trigger your automation. Motion detection is intended to respond to movement. Presence detection is intended to notice occupancy, including smaller movements. Neither label guarantees the result in your room.

For a hallway light, movement may be enough. For a desk or sofa, check whether the sensor can report occupancy while someone stays in place, whether your platform receives that reading, and how your automation handles a period without detection.

Power and hub requirements

Battery life and detection ranges are manufacturer specifications, not measurements from SHWF. Check them against your intended placement rather than comparing the largest number alone.

The platform can change the answer

FP2 exposes zones and light level to Apple Home and Home Assistant. Alexa and Google receive presence without the light-sensor function. FP2’s SmartThings support for the US version is unresolved.

SwitchBot documents a Google Home limit: its Presence Sensor cannot be used as an automation condition. Apple use requires a SwitchBot hub, with a beta setup route for bridged devices; a home hub is needed only for control away from home and automations. Home Assistant can use Bluetooth directly; the cloud route has different requirements.

THIRDREALITY names Home Assistant’s Zigbee routes and SmartThings. Alexa requires an Echo with a built-in Zigbee hub, and its precise functions are not itemised. Apple and Google support remain unknown; a bridge route for another THIRDREALITY product does not establish one for R2.

Meross documents presence and light readings on Matter for MS600. Its Alexa and Google descriptions do not itemise the exposed readings. SmartThings functions and Home Assistant’s motion/presence readings remain unconfirmed.

Placement still matters

THIRDREALITY warns that strong or repetitive movement, including fans, may trigger R2. Use the manufacturer’s placement and tuning instructions, and check for unintended triggers before relying on an automation.

Motion sensors have their own feature differences. Aqara Motion & Light P2 needs a Matter controller and Thread border router; Alexa does not receive its light reading. Hue Motion needs a Hue Bridge. A motion sensor plus a thoughtfully configured delay may fit a different task from a presence sensor.

Check the whole automation

Confirm the sensor reading, the platform’s trigger support and the device being controlled. Add required hubs, power supplies and batteries to the purchase. The sensor directory and checker show the recorded routes and unresolved questions.