HlK-LD2410C radar presence sensors, MQTT and home assistant [DRAFT]

2023-10-29

These guys are mmWave radar presence sensors which can be used to detect human presence (unlike PIR sensors, they can also detect stationary presence), which can be found on amazon or aliexpress for a few dollars:

Pinout:

• RX / TX - serial port
• Out - HIGH when presence detected
• VCC - 5-12V, 5V recommended
• Gnd - Ground, as you'd expect.

The by far simplest way to use them is to use the Out pin, as it's high (3.3v level) when presence is detected / low otherwise.

Serial protocol

TODO..

BLE App

Arduino & Home assistant integration

Home assistant sensor auto-discovery

How well do they work?

I dunno. I just got it setup.

References

• Manufacturer site
• Serial protocol

Prev: Making a Raspberry Pi Pico (RP2040) PCB as a beginner [DRAFT] Next: Nix: Getting started with Flakes