Weight sensor/ Load Sensor anyone?

Anyone know if there exists any small and inexpensive weight sensors/ load sensors compatible with the SmartThings hub. My plan is to put one under each family members bed to detect when each one gets out of bed in the morning

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I want to do this too.

The goofy way (without at least one or two load cells) is put a stiff spring on the bed leg(s), and use the deflection to drive a switch. A reed switch might be too sloppy, but I haven’t played with it.

Want to avoid spring noise and unnecessary motion of the bed leg, so something like a load cell would be better, but only powered intermittently. I guess that part is easy with a motion sensor routine. That would be able to tell if 0, 1 or 2 were in bed. You can even identify who is in bed by weight. Fun.

But if all you want to know is “are they up”, a masked motion sensor is simpler.

Someone did something similar with a pressure pad wired to a door sensor. It’s relatively easy and inexpensive.

You can find pictures of the projects, parts and custom code in this thread:

Yep, pressure mats are the usual way of doing this. There are number of models available. Some register weights as low as 5 pounds, some go up to the weights of automobiles. The inexpensive ones typically just have an on/off state, with on being triggered at around 25 pounds. Then you attach it to a contact sensor that can communicate with the SmartThings hub when the state changes.

In addition to the project @viguera already shared, there was another topic which started out discussing motion sensors but quickly evolved into a discussion of pressure sensors that would be small enough to fit in a chair. So it might also be of interest.

There’s yet another alternative coming up next year although it’s not yet available for sale. SmartThings has announced a new “sleep sensor” which is a pressure Mat that will go under the mattress. It’s intended for measuring quality of sleep, but it should also give you exactly what you want: an indicator of when someone is in or out of bed. That one will not require any device modification, and should work out of the box with SmartThings.

So if you’re willing to wait for it, and you’re willing to spend more thañ the DIY versions, the sleep sensor might be exactly what you want.

I’m actually quite excited about this one. As someone who is quadriparetic, I spend most of my time in one of three places: my wheelchair, my recliner in the living room, and my bed.

I can think of a lot of different use cases for home automation as I transfer from one to the other. :sunglasses:

On the other hand, if you want to keep your budget as low as possible, options mentioned in the Smart Chair topic are probably the least expensive.


Thanks for all the great responses. It’s really appreciated. I think I will go for the pressure mat and do something like Samsung’s SleepSense myself. Then combine it with motion sensors to know if the person’s intention is to stay up or just went to the bathroom etc. And then I will kick-off all the funny things

So i want to do this because I’m mildly frustrated by timed “good night!” Routine failing. And this seems like its better anyway. I dont have kids, but I am already imagining how great it is for that. (And i also considered how awesome it might be for a parent of teenagers to trigger the alarm when a teens bed has double the body weight on it haha) anyway, has anybody done this and what device did you use? The sleepsense hasnt had any more info come out since september.

if all you want is good night, then condition “When Things Quiet Down” has worked ok, rarely fails for me.

If you can’t wait for the Samsung sleepsense, then the load cell output would also require a MIMO device to read it as something like 0-2V. Hacking a bathroom scale is probably the easiest way to get them cheap. Probably need two power supplies, one at 3-6V for the sensors and another at 12V for the MIMO.

Now it just sounds silly to me. A motion sensor under the bed, or masked and aimed properly, will be much simpler.

Thanks, i’ll take a look at doing a bathroom scale hack if timed events continues to be an issue. One problem with motion sensors for me is that i have a dog larger than my wife. So pressureweight sensors in bed is about as intelligent as it gets for automating night time routines. Sleepsense was teased in the beginning of september and supposed to be available in 2015… we havent heard a peep since… so i wont be holding my breath.