KENZY-LD2450 ·

kenzy.ai · Documentation · Install

In-node mmWave presence for Kenzy: an HLK-LD2450 radar on the node's UART gives every room level presence — someone sitting still is still here, where a motion sensor sees an empty room after its timeout.

Installed, a node gains the sensor, a Room radar dashboard panel (live target view, drag-to-draw ignore zones), per-room occupancy evidence in Kenzy's presence model, and — when the MQTT integration is enabled — an occupancy entity in Home Assistant. Not installed, none of that exists: no config keys, no panel, no cost.

Install

On the server host and on each node host that has a sensor:

pip install kenzy-ld2450

(into Kenzy's environment — for the standard install that is ~/.local/share/kenzy/venv). Restart kenzy-server / kenzy-node; add-ons are discovered at process start. The dashboard's Settings → Add-ons card shows what's installed and why anything failed to load.

Wiring (Raspberry Pi GPIO UART)

The LD2450 talks 256000-baud UART (fixed by the sensor — not configurable):

Pi setup, once per node:

1. enable_uart=1 in /boot/firmware/config.txt (or raspi-config → Interface Options → Serial Port: login shell No, hardware Yes).
2. No console=serial0,… in /boot/firmware/cmdline.txt — the kernel console must not own the port.
3. The kenzy user in the dialout group: sudo usermod -aG dialout $USER.
4. Reboot. The sensor is then /dev/serial0 — the add-on's default device, so a standard wiring needs no configuration at all.

A USB-to-TTL adapter (CP2102 or similar, 3.3 V logic) works identically: wire the same four lines and set the device to /dev/ttyUSB0 in the panel.

Configuration

Everything is editable from the Room radar panel per node (saved into Kenzy's server-owned config and applied live — no restarts). The keys, for YAML users (addons.ld2450 in a node's config):

Server side (configs/addons/ld2450.yaml):

Home Assistant

With Kenzy's MQTT integration enabled (integrations.mqtt in server.yaml), each sensor-bearing node publishes — via MQTT Discovery, onto the node's existing Kenzy device in HA:

• binary_sensor.…_radar (device class occupancy)
• sensor.…_radar_targets, sensor.…_radar_nearest

Only nodes whose sensor has actually reported get entities; they share the node's availability, so an offline node reads unavailable, never "clear".

Compatibility

Requires the kenzy plugin seam (API v1). An incompatible pairing refuses to load visibly (Settings → Add-ons says why) and Kenzy-driven upgrades move core and add-ons as one resolver set, so pip install -U through Kenzy can't strand a broken pair.