POCKET LAB PORTAL INVESTIGATION
Millimeter-Wave Presence Sensors: The Tiny Radars That Know You Are Still There
How 24 GHz and 60 GHz room sensors detect motionless occupancy, map zones, and sometimes track breathing-scale movement.
A passive infrared sensor usually needs visible motion before it reacts. A millimeter-wave radar sends radio energy into a room and analyzes the reflections, making it possible to detect much smaller movement—including the subtle motion of someone sitting still. That capability can make lighting and ventilation automations feel almost psychic, but only when placement, tuning, privacy, and the exact radar mode match the job.
Our current shortlist
These devices cover three different jobs: a finished multi-zone room sensor, a local Home Assistant platform, and an experimental breathing-scale radar kit. Select the job first; the word mmWave alone does not make them interchangeable.
Affiliate disclosure: Portal Surf may earn a commission from qualifying Amazon purchases. This does not change the price you pay. These selections are based on published specifications and documented capabilities; we have not completed hands-on testing.
Best turnkey multi-zone room sensor
Aqara Presence Sensor FP2
Aqara documents 60–64 GHz radar, room mapping, multi-person detection, and zone-based automation without requiring an Aqara hub.
Verified capabilities- 60–64 GHz radar
- Up to 40 m² documented room coverage
- Up to 30 configurable zones
Watch out: It requires 2.4 GHz Wi-Fi and the Aqara app for setup. Placement and mapped edges matter, and fall detection is not a substitute for an emergency-response system.
Best budget DIY presence module
Hi-Link HLK-LD2410C
The compact 24 GHz module exposes presence and distance-oriented data over UART and supports Bluetooth configuration, making it a practical ESPHome and microcontroller building block.
Verified capabilities- 24 GHz presence radar
- UART output and Bluetooth configuration
- Moving- and stationary-target sensing
Watch out: This is a bare electronics module, not a finished room sensor. It needs safe power, an enclosure, a controller or host, and careful sensitivity tuning.
Best breathing-scale radar experiment
Seeed Studio MR60BHA2 Kit
The 60 GHz development kit combines presence sensing with breathing- and heartbeat-related telemetry for embedded projects and Home Assistant experiments.
Verified capabilities- 60 GHz mmWave module
- Presence plus breathing and heartbeat-related outputs
- XIAO ESP32-C6 development platform
Watch out: Treat its vital-sign outputs as experimental data, not medical measurements. Reliable results depend on subject count, posture, distance, angle, and environmental motion.
Evidence standard: technical claims are checked against manufacturer or project documentation. Amazon is used as a purchase destination, and listing details should be verified before checkout.
Presence is not the same as motion
Traditional PIR sensors react to changes in infrared energy across their field of view. They are fast and inexpensive, but a person reading quietly can appear absent. Millimeter-wave modules analyze reflected radio signals and can remain responsive to much smaller movement. That makes them useful for occupancy-driven lighting, desk zones, room-level HVAC, and accessibility experiments.
The label mmWave does not guarantee identical behavior. Some modules report only occupied or clear, some estimate distance, and tracking-oriented radars can report target coordinates. A model optimized for moving-target position may be worse at holding a completely stationary target than a simpler presence detector.
Zones turn one room into several sensors
A zone-capable device can treat a bed, desk, sofa, or doorway as separate automation areas. Aqara documents room coverage up to 40 square meters and as many as 30 configured zones for the FP2, while the Everything Presence Lite documentation describes up to four configurable zones with its supported tracking radar.
Zone maps are still estimates. Furniture, mounting angle, reflective surfaces, moving fans, pets, and activity beyond light interior partitions can create false targets. Begin with one important zone and observe it before building automations around an entire floor plan.
Breathing-scale sensing is specialized
Seeed Studio's MR60BHA2 is a 60 GHz development kit designed to report presence plus breathing and heartbeat-related measurements. That is a fascinating embedded-sensing capability, but it should be treated as experimental telemetry rather than a diagnosis, safety monitor, or substitute for regulated medical equipment.
Vital-sign-style radar needs controlled placement and a comparatively still subject. Multiple people, posture, bedding, distance, angle, pets, and environmental motion can all change what the algorithm can resolve. Buy it for experimentation and integration—not for a health conclusion.
Local control and privacy matter
A presence sensor may create a detailed pattern of room occupancy even when it does not capture images. Decide whether processing and automation remain local, whether a vendor account or cloud service is required, which smart-home platforms receive zone events, and how long any history is retained.
Builder-oriented ESPHome devices offer substantial local control but demand firmware and Home Assistant knowledge. Turnkey Wi-Fi products reduce assembly while adding application, account, and ecosystem dependencies. Neither route is universally more private unless it is configured and maintained deliberately.
Use the smallest reliable automation
Start with a low-consequence task such as keeping a reading light on while a person remains at a desk. Tune range and exclusion zones, then test stillness, entry and exit delay, pets, fans, curtains, adjacent rooms, network loss, and power recovery. Keep safety-critical lighting, fall response, security, and medical monitoring on systems designed and validated for those roles.
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