Motion Detection - Sensor Advice

Hello there :wink:

I’m pretty new to Home Assistant. I just had a few gadgets here and there but now i want to do it all! I have a reasonable budget but not too high.
I set up a Server with a Docker Host with Home Assistant, Mosquitto and Unifi so far.
I really like the Xiaomi Sensors because they’re cheap and seem to work pretty good but i want to have my own ZigBee Base for it.

Regardless BTT. My Question is how the Sensors especially the Aqara ones detect motion. If i sit still on the toilet for 10 mins (happens) and the lights turn of like it is at the moment with my hard wired motion sensors (cuts power to light if there is no motion) it’s pretty stupid. But if i just reach in to the closet in the bathroom to get the window cleaner, boom 15 mins. light on. It’s all LED so the power cost isn’t that much of a problem but it still annoys me.

Is there sth like a presence detection which not only senses motion but for example body heat?
So that it can turn of the lights maybe 5 seconds after i leave the room?

Thanks in Advance :wink:

Oh and thanks for all the people helping and giving tipps. I have been lurking for quite a while now to get tipps and infos.

Have a nice Day
Kind Regards

There is a nice explanation how PIR’s work here :

In short : they all work on moving body heat, but most commercial ones have a time-out, so they don’t turn off after 15 seconds.

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You can set a timer that resets when detecting movement again.

There are also other sensors that detect the person instead of the movement, but they are much more expensive.

With home assistant you could build presence detection with bluetooth (if you have something like Mi Band. You’ll need esp32.

Your best bet is to create an automation and set a timer. Its how i have mine and almost works well.


Thank you both!

for some reason i didn’t think about looking into the wikipedia article.
So probably an active sensor would be the solution…
The normals smart home market doesn’t seem to offer Active Sensors as far as i can see

I’ll try it with a timer and the Aqara Sensors.

Best Regards

Hello, please do not understand evil, have read your “post” and only laughed. Then I had two ideas …
The first one was this one …

and the second one here …

But now seriously…
Your bathroom is very likely to have a door … From Xiaomi there are good door and window contacts. Use the PIR sensor to turn on the light and turn off the light by using the door and window contact.

Sorry is just an answer for fun, the solution is already there …

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Hi VolkerKa

i like the idea of a presure sensor in the toilet…maybe…nah that would be too crazy…wouldn’t it?
I can already see it:

Guest: Whats that raspberry Pi doing on your toilet seat?
Me: Science!
Guest: What?

There are always many solutions to a problem, that idea is pretty nice with the sensor on door and window. I’ll keep it in mind :wink:

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If you don’t want to use pressure sensor, then you still can add a wireless door sensor for the toilet seat. So if it is open, then turn on lights :slight_smile:

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I’m a big fan of the xiaomi sensors too. After two years with, I’ve gotten loads of stuff like this dialed in. I’ve tried connecting the xiaomi sensors to Smartthings hub but that was a bit too slow, then I tried DeConz, but deconz kept dropping them, so I’ve been cutting them over to a xiaomi hub.
For the bathroom logic, I’ve got 3 xiaomi sensors, motion, humidity, and door contact that control the majority of the bathroom logic. You can use logic and conditions to dial things in pretty well. The motion detector is a binary on/off, and I think it stays on for 45 seconds then switches back to off, unless it detects motion again. (Not 100% on that 45 seconds, might be 90) You can use this on/off window to your advantage. If the motion goes from on to off after 50 seconds, then it’s likely a quick pop in, and you can turn the lights off. If the motion detector takes longer than 50 seconds to go off, I’m likely doing something in the bathroom, so delay off until 5 minutes after last motion. If the door closes after motion, I’m likely pooping, and so the lights shouldn’t turn off until the door opens again. If the humidity spikes, (you can use a trend sensor to capture humidity spikes) then switch on a “shower mode” binary sensor, that disables the motion light connection, until humidity drops in the other direction, which indicates out of the shower, and turns off the “shower mode”, which allows the motion/light connection to return to normal. You can really nail it down with presence detectors, bed occupancy sensors, and the workday sensor. I try to avoid custom sensor builds, because building custom means a lifetime of maintaining custom - and is always changing, so things do break.

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