How This Guide Was WrittenThis is editorial research — not hands-on lab testing. We cross-reference manufacturer specifications, CSA/Matter certification databases, and recurring themes in Amazon verified reviews and owner forums. Product recommendations are current as of 2026 and include Amazon search links so you can verify pricing before buying. Focus areas for this guide: lock credentials, camera storage models, and security sensor placement.
Why PIR Motion Sensors Fail at the Worst Moments
PIR (passive infrared) detects heat movement — walking past the sensor. It does not detect:
- You sitting still on the couch
- Someone sleeping in bed
- Slow movement toward the sensor
Result: lights turn off while you’re still in the room. Automations misfire. Users disable the automation entirely.
mmWave Fixes the Stationary Problem
Millimeter-wave radar (60GHz in Aqara FP2) measures distance and micro-motion — breathing, typing, reading. Presence persists until you actually leave.
| PIR | mmWave (FP2) | |
|---|---|---|
| Stationary detection | No | Yes |
| Price | $15–25 | $79 |
| False “vacant” | Common | Rare |
| Best placement | Hallways | Living room, office, bedroom |
Where to Deploy Each
- Hallways, garage entry — PIR is fine (you’re always moving)
- Living room, office, primary bedroom — mmWave worth the premium
- Bathrooms — PIR usually sufficient; mmWave if shower scenes matter
Recommended Hardware for This Setup
These are specific products that match what this guide describes — not generic placeholders. Verify current pricing on Amazon before buying.
1. Aqara FP2
mmWave presence with five zones — detects stationary occupancy PIR misses entirely.
Check Current Price on Amazon (paid link)
2. Sonoff SNZB-06P
Budget mmWave + PIR hybrid for Zigbee hubs at $19.
Check Current Price on Amazon (paid link)
HTR Takeaway
- Start here: Aqara FP2 in rooms where you sit still; cheap PIR Sonoff in transit areas.
- Avoid: PIR-only in home office or TV room — you'll fight the automation within a week.
- Bottom line: mmWave is replacing PIR anywhere occupancy matters for automations, not just motion.