I’ve been going back and forth with this idea for a while… Currently all smart devices in my home are off the shelf, I’ve been trying to stay clear of DIY projects due to the learning curve and time requirement.
So here’s my problem… the only off the shelf device I can find that could help with couch occupancy is the xiaomi vibration sensor, but that would probably be the worst solution as checking for vibrations / tilt will not always work. (sitting still on the couch will not give any results)
Then there’s pressure mats, which would require DIY, but I don’t think those are a solution for my couch, as I can’t add one under the cushions. (cushions are not detachable)
Then I was thinking this could be done with distance sensors (measuring the distance from the bottom part to the cushion), which should be accurate enough, but again a DIY project as I couldn’t find any off the shelf smart distance sensors.
Some input from others here could help a lot, has anyone gotten good results with couch occupancy? Or does anyone have good ideas for (preferably) off the shelf devices that can help with this? And lastly, if there is no other better option… I’d also like to hear input about the best DIY project that could help with this.
The hx711 load cell thing would definitely work… could even have it report the weight of the couch occupants, if that’s useful (like determine how honest your date is about their weight, lol).
I have been playing with rcwl-0516 human body sensors and wonder if they might work for what you need. They very reliably sense even the slightest motion within 10-15’ of the sensor (seriously, anything more than careful light breathing, and you’ll be instantly recognized by it), and they don’t need LOS like pir. So you could potentially bury one under the couch, and it will trigger if there’s any human body motion within range. The downside is if nearby motion would ruin the automation, it may not work. Also, it can pass through thinner walls etc. Still may do what you want though… I figure the reason most ppl want couch/bed detection is because pir fails if you’re a bit too still. These new microwave body sensors can fill that gap as they require much less motion, and that motion doesn’t have to be line of sight (like moving your hand on the opposite side of your body will trigger it). So it would totally work for like, reading a book or watching a movie. OTOH, if you sleep very still, you may still need load cells for that.
I’ve done exactly this but I’m afraid it’s not going to be very helpful. I have a triple electric recliner. Typically the switches are connected directly to the motors but instead I’ve connected both sides to an Arduino. It means the seat can be controlled by HA and extra functionality can be added such as touch to recline and double press to recline the entire couch.
I use whether the feet are up on any seat as presence detection. PIRs don’t detect movement when you’re watching a film or you’ve fallen asleep on the sofa. If I didn’t have this setup I would use load sensors under each foot. Or some kind of flexible sensor within the cushion to detect the movement when someone sits down.
Sofa occupancy is going to be really helpful for your automations!
So what did you end up going with, the radar sounds like an interesting idea. But I think the range would be too much. Can it be limited to maybe 200mm?
