Building a bed occupancy sensor for home automations

[Eniqmatic]

Hey guys!

 

Thought I’d share my bed occupancy sensor (yes I know, more bed occupancy sensors based on load cells!) and hopefully make it easy for anyone else that wants to replicate.

 

Using those cheap 50kg load cells under each corner of the bed, a HX711 board, Wemos D1 Mini and of course Home Assistant!

 

One thing I found hard to find information on was how to mount the sensors. I tried a few things but ended up 3D printing casters/holders for my bed legs and allowing the load cells to slot into them, this stops the bed sliding around on the cells and interfering with the reading. This method keeps everything secure and ensures each cell is in the exact same position.

 

See attached pictures.

 

So what do I use this for?

This has greatly improved my automations:

• Ensuring that when we are both in bed, every light and media player is turned off, door locks are set and the house alarm is set to “armed home”.
• I have lights that are automated through Home Assistant when motion is detected, I add a condition to these automations not to trigger these lights when we are both in bed, this is so that our dogs do not trigger lights all night.
• During night hours, the bathroom light comes on at a very dim brightness if one of us exits the bed during the night. This is great for not being blinded when getting up to the bathroom during the night!

I’ve created a full guide here

 

Github code:

https://github.com/EverythingSmartHome/mqtt-bed-sensor

 

 

[myselfolli]

This is pretty sweet, well done!

[Eniqmatic]

2 minutes ago, myselfolli said:

This is pretty sweet, well done!

Thank you, appreciate it!

[Eniqmatic]

4 minutes ago, James Evens said:

Share your enclosure. There are quite some 3d printer owner who don't know fusion.

It's this one, I didn't make it: https://www.thingiverse.com/thing:3564942

 

I made the bed enclosure, but sharing that would be useless since it's unique to my bed!

[Euchre]

So how much does that all cost?

 

Nursing homes, assisted living facilities, and hospitals have long used bed alarms and chair alarms to monitor patients and residents, hoping to avoid falls and injuries. Recent studies concluded that they actually happened more in facilities that used them, because staff didn't pay attention to them, and the alarm just tells them the accident has already happened. As a result, such devices are being abandoned and removed from use. They were already relatively cheap in terms of medical devices, often ~$100 each. Now they aren't as precise as devices based on load cells or strain gauges, but do you really need more than a toggle switched signal? I'd suspect as they fall from use, their prices will only drop. Just a bit of hacking and you've got something that puts out a simple voltage signal for your presence sensor. How about that? Maybe you've already got an Arduino or Pi with a sensor board or input you can utilize?

 

Something to consider.

[Eniqmatic]

15 hours ago, Euchre said:

So how much does that all cost?

 

Nursing homes, assisted living facilities, and hospitals have long used bed alarms and chair alarms to monitor patients and residents, hoping to avoid falls and injuries. Recent studies concluded that they actually happened more in facilities that used them, because staff didn't pay attention to them, and the alarm just tells them the accident has already happened. As a result, such devices are being abandoned and removed from use. They were already relatively cheap in terms of medical devices, often ~$100 each. Now they aren't as precise as devices based on load cells or strain gauges, but do you really need more than a toggle switched signal? I'd suspect as they fall from use, their prices will only drop. Just a bit of hacking and you've got something that puts out a simple voltage signal for your presence sensor. How about that? Maybe you've already got an Arduino or Pi with a sensor board or input you can utilize?

 

Something to consider.

Total price is less than $20. You are correct, they have these devices and obviously they work well. I saw many of these in my research. The problem being that they are often to sense a single person, since hospital beds are usually single beds. This isn't a deal breaker but its a nice feature to be able to tell how many people are in the bed, not just IF someone is in the bed. Hopefully that makes sense!

 

Appreciate the comment, it was something I looked into!