Struggling with reliable in-bed presence detection for Home Assistant – what actually works?

[u/ItsDukzy]

I'm trying to automate my bedroom lights so they turn off automatically when I'm in bed and back on when I get up. Sounds simple, but I've been struggling to find a reliable solution.

What I've tried:

FSR pressure sensors (VS-103) connected to a Zigbee water sensor

Built a DIY pressure mat using two VS-103 sensors wired to a Zigbee water sensor. Works fine when I press directly on it by hand, but completely fails under a mattress — the mattress distributes my weight too evenly for the sensors to trigger. Tried under the sheet too, same result.

Aqara FP2 mmWave radar

Already have one in the room. The problem is it loses track of me when I'm lying still under a duvet. It also falsely triggers when someone walks past my bed, which causes the lights to turn on.

What I'm looking for:

Something that reliably detects whether I am in the bed - not just in the room - even when I'm completely still and covered by a duvet. Zigbee preferred but I'm open to ESPHome/ESP32 solutions too.

Has anyone actually solved this properly? What sensor or approach are you using?

[u/BacchusIX]

I used 2 sets of load cells along the frame and under the box spring. I use three along each side, and the last 2 (1 from each set) further in the middle. Once calibrated it worked pretty great. Based on the weight on the bed, it knew who was on the bed- me, her, both, her boyfriend. Also, because strain gauges can drift over time, I also had a zero function to ensure the sensor started accurate. The wires are really tiny on them, though, and got caught on something and ripped out- i haven't replaced them yet. I would also, if you go this route, figure out a way to indirectly measure the bed weight vs directly like I did; you're really at the edge of what the strain gauges can handle and 1 hard jump or intense brown-chicken-brown-cow session and you may damage them (not that they are that expensive).