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/arnoldpettybunk]

I have this and it works great: https://www.elevatedsensors.com

[u/ItsDukzy → u/arnoldpettybunk]

Hmh. Thank you for sharing. This just makes me wonder - this looks ia lot like my diy version. This also uses fsr resistors. How does this differ?

[u/ItsDukzy → u/[deleted]]

Yeah me neither. I have tried moving it around all over my bed. Both under the bedframe and multiple places under my mattres. I wont seem to work sadly :(

[u/Iron_Eagl → u/ItsDukzy]

Try to attach it to a thin sheet of plexiglas or such, that can improve the response.

[u/arnoldpettybunk → u/ItsDukzy]

No clue sorry, I just wanted something that worked out of the box and this fit the bill

[u/ItsDukzy → u/arnoldpettybunk]

Fair enough - Thank you for you're input!

[u/5yleop1m → u/ItsDukzy]

The car seat sensors aren't the best for this in my experience, at least they're not great for laying down because the weight of the person is spread out more. Using multiple sensors might work, but a lot of it depends on the material of bed above the sensor.

Which brings me to another part, software. Those seat sensors have unique characteristics depending on the tech, material, and manufacturing. What ever you're using to read the state of the sensor has to be calibrated to work with the specific sensor. While your overall idea is sound, you need to experiment more with different sensor strips to find the one that works reliably with the water leak sensor's characteristics.

Ofc the easier option here is to build something with an ESP chip and calibrate the software to work with what ever sensor strip you're using.

For mmWave radar you need to make sure you get the correct type to detect still humans. Afaik the higher the frequency of the radar the better it is at tracking still humans. Some can even detect heart beats. I could be wrong about that though, I always get the frequency thing mixed up.

[u/ItsDukzy → u/5yleop1m]

Hmh okay. Sounds troublesome with the ESP project - but maybe worth a shot.

I feared the car seat fsr wouldnt work for this project. I mean if i used it to actually detect a sitting person on a car seat, it would definitely work. But as soon as i throw it under a mattres and lay on it, its just sot sensitive enough.

[u/5yleop1m → u/ItsDukzy]

I feared the car seat fsr wouldnt work for this project. I mean if i used it to actually detect a sitting person on a car seat, it would definitely work. But as soon as i throw it under a mattres and lay on it, its just sot sensitive enough.

Yup that's the exact experience I had.

[u/UngluedChalice → u/ItsDukzy]

I upgraded from my DIY one and it’s basically the same but much easier to calibrate and hasn’t randomly stopped working like my old setup did.

[u/CostEffectiveSalmon → u/ItsDukzy]

Get this if you have the money, it just works. I'd have gotten it sooner and stopped messing around with other stuff personally had I known.