The Problem with Motion Sensors
Every smart home owner has experienced it: you’re reading on the couch, perfectly still, and the lights turn off because the motion sensor thinks you left.
Traditional PIR (passive infrared) motion sensors detect movement, not presence. If you’re not moving, you don’t exist.
Enter mmWave Radar
Millimeter-wave radar is a game-changer. It detects:
- Breathing: Even a sleeping person is detected
- Micro-movements: Typing, reading, eating
- Distance: Know exactly where someone is in a room
- Multiple people: Count occupants accurately
- Speed and direction: Know if someone is entering or leaving
No Cameras Required
The beauty of mmWave is that it’s not a camera. It doesn’t create images. It can’t identify faces. It measures radio wave reflections - completely anonymous presence data.
This is privacy-preserving presence detection.
What You Can Do With Real Presence Detection
- Lights that truly follow you: On when you’re there, off when you leave - even if you’re sitting still
- HVAC optimization: Only heat/cool rooms with people in them
- Security: Know if someone is in your home without cameras
- Sleep tracking: Detect sleep/wake states for bedroom automations
- Elderly care: Detect falls or unusual inactivity patterns
What a Hub Does With Presence Data
When a local hub integrates mmWave presence detection, it can know:
- Which rooms are occupied
- How many people are in each room
- Whether someone is active or resting
- Movement patterns throughout the day
With local processing, this data never leaves your home. It’s used to drive automations that make your home genuinely intelligent.
Getting Started
If you want to experiment with mmWave presence detection today:
- Aqara FP2: Excellent Zigbee mmWave sensor, works with most hubs
- Everything Presence One: ESP32-based DIY option with ESPHome
- LD2410: Affordable bare sensor for DIY integrations
The era of “waving at the lights” is ending.