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Updated: Apr 2026

mmWave Presence Sensor
Zigbee

mmWave presence sensor with HLK-LD2410S and XIAO ESP32-C6, integrated into Home Assistant over Zigbee. Detects presence even of motionless people, with no false negatives.

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Video series

Overview

Traditional PIR sensors only detect motion: if you sit still in an armchair reading, you fool them. mmWave (millimeter-wave) sensors detect presence even of completely still people, by analysing the micro-movements of breathing.

This project combines the HLK-LD2410S sensor with a XIAO ESP32-C6 to get a native Zigbee presence sensor, integrable into Home Assistant like any other Zigbee device — no extra bridges, no cloud, no external dependencies.

Why Zigbee and not Wi-Fi

The ESP32-C6 supports both Wi-Fi and Zigbee. Zigbee was chosen because it plugs directly into the home’s existing Zigbee network (via Zigbee2MQTT), draws less power and adds no traffic to the Wi-Fi network.