Make Your Own mmWave Sensor | Easy DIY
Sick of smart lights turning off the second you sit still? In this video, I build a DIY mmWave presence sensor for Home Assistant using the HLK-LD2450 and an ESP32-C3, so your automations can detect presence (not just motion).
💡 Parts I used:
HLK-LD2450 mmWave radar - https://s.click.aliexpress.com/e/_c40...
ESP32-C3 (or similar ESP32 board) - https://jrattechworks.com/parts/xiao-...
Optional: BMP280 (temp/pressure) - https://s.click.aliexpress.com/e/_c3V...
Off-the-shelf enclosure (or 3D print your own) - https://s.click.aliexpress.com/e/_c3f...
Full guide, STLs and YAML - https://jrattechworks.com/building-a-...
mmWave is a big upgrade over a standard PIR. Instead of only triggering on movement, it can keep lights on while you’re on the couch, working at a desk, or watching TV.
I walk through the full build, wiring, firmware setup (ESPHome), and Home Assistant testing, plus the real-world pros/cons like false triggers, placement tips, and what you can tweak to make it behave properly in a room.
If you’re deciding between building one yourself or buying something like an Aqara FP2, I also cover cost, effort, and what you gain by going DIY.
👇 Drop your questions in the comments, happy to help with wiring, ESPHome config, and Home Assistant automations.
⏱ Chapters:
0:00 Intro
1:11 mmWave vs PIR
2:47 Hardware Used
4:09 Cost
5:32 Wiring
5:59 Gotchas to Avoid
6:43 Firmware Setup
8:55 HLK App
9:25 How It's Behaved So Far
10:14 Things I'd Change
11:08 No 3D Printer?
11:23 Final thoughts
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Information provided in this video is for educational purposes only.
If you attempt to recreate/replicate anything you’ve seen in this or any other video, you’re doing so at your own risk.
Some of the links in this post may be affiliate links. If you buy through them, I may earn a small commission at no extra cost to you.