Sofa pressue sensor - is there anybody on the sofa

Hi, I have a sofa in a bay window, a bit like this
Due to draft from the windows when it cold (I’m in Denmark) I will install inferred panels above the sofa, and I like to control them in an smart way.
I like to have some kind of hardware which detects if anybody is sitting in the sofa if nobody is the infrared panels should be turned off.
Does anybody know of a smart device that can do this?

I’m thinking about using a xiaomi motion sensor, but it will turn off if I very still, which might be annoying.

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I’d look for a weigth sensor. If the weigth on the sofa is > ? There must be someone sitting on it.

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You may have much better luck in forum on wearables or other DIY fora, I don’t know a commercial solution, but have seen stuff used in wearables that may work for your use case…if you are willing to tweak stuff…a pressure sensitive conductive sheet has been used in sneakers to detect steps

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Once, many moons ago, my first foray into DIY electronics involved the creation of a Dance Dance Revolution pad (damn I’m old).

The pads worked by using two sheets of thin sheet metal (can’t remember the gage) separated by non-conducting spacers (I think I used aluminum washers) at the corners or edges that keep them separated a couple of mm. Solder wires to each sheet wired to GPIO like a reed or contact sensor. You can experiment with the gage of the metal and size of the sheets to control how much weight is required to trigger the sensor.

When putting weight on the top sheet it will flex and touch the bottom sheet completing the circuit, showing presence on the sofa.

Slide it under the cushion and I would recommend using one of the wearable microcontrollers like the Adafruit FLORA or GEMMA V2 for their thinness.

Personally, I would probably wire this directly to relays that control the infrared panels rather than making it talk to OH, unless you have a smart cat or dog. :wink:


i use the same type of device for my halloween projects. cut the metal sheets and a piece of foam board the dame size. then cut a large area out of the middle of the foam board. works like a charm.