Presence Sensor — mmWave Room Detection
Presence Sensor — mmWave Room Detection
True presence detection, not just motion. Detects a still body breathing, not just waving.
Step 1 Unbox & Check the BOM
Verify every part against the Bill of Materials on the right. The ESP32-C3 ships pre-flashed with the presence-detection firmware.
Step 2 Wiring
The mmWave module talks to the ESP32 over UART. Power it from 5V — the 3V3 rail can't supply enough current during a detection pulse.
Step 3 Flash Firmware (already done)
Pre-flashed with the ESPHome config below. Reports a binary occupancy sensor and an optional distance value (mmWave ranging).
uart: rx_pin: 5 tx_pin: 4 baud_rate: 115200 binary_sensor: - platform: mmwave name: Room Occupied
Step 4 Mount
Mount the sensor ~2m high, facing the room's center. Avoid pointing it at windows — mmWave passes through glass and will detect movement outside. Tilt down 15°.
Step 5 Connect to Home Assistant
HA auto-discovers the occupancy sensor. Use it to drive automations: turn lights off when the room has been empty for 5 minutes, pause HVAC when nobody's home. Combine with distance for fall detection (advanced).
Troubleshooting & FAQ
False occupancy when the room is empty
A ceiling fan or curtains moving under 30cm/s can trigger a false-positive. Set the sensitivity to medium in the YAML, or add a 10s confirmation delay.
Misses a person sitting very still
Check FOV — the sensor has a 120° cone. If the chair is outside the cone or beyond 6m, relocate the sensor or add a second one.
Does it detect pets?
Yes — the kit includes a pet_immune config that ignores objects below 40cm tall. Disable it if you want pet-based automations.
Presence Sensor Kit
$34.99
| Part | Model | Qty | Price | Status |
|---|---|---|---|---|
| Microcontroller | ESP32-C3 | 1 | $6.99 | In Stock |
| mmWave module | HLK-LD2410 | 1 | $12.00 | In Stock |
| Enclosure | 3DP-PS-01 | 1 | $8.00 | In Stock |
| Jumper wires | JP-10cm | 4 | $2.00 | In Stock |
| USB-C cable | USB-C 1m | 1 | $6.00 | In Stock |
| Kit Total | $34.99 | |||