Bluetooth Presence Detection And You! | Level One Techs

This is a companion discussion topic for the original entry at

Will this act like a bluetooth beacon able to position someone with a decent level of accuracy inside a house?

There are now apps to triangulate things using BT. This alone will not do it - you need to either move precisely or you need more beacons.

This is similar to pam.d modules in the past - are you close, yes or no. Not really something to locate items in the room.

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Just for my understanding… this only works when BT is turned on on the phone right? So mother-in-law-detector would only work if she had BT turned on all the time?

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I had a similar idea using well spaced blue tooth le beacons and an ap w/ a learned model to do room based localization in a building. There are several research papers on this as well. In this case the app would be deciding where it is by looking at the surrounding beacons rather than the beacons themselves deciding if you are there.

I was wondering if the beacons were all ‘facing’ good positions where their signals would not overlap very much, maybe using an insulator like aluminum to block a beacon from reaching behind it or beyond a room.
You could more easily use them for rough room based localization in the house.

Would require a lot of prep but hopefully the layout of your house isn’t going to change drastically so that it would be at least semi practical.

That is a weakness …but you would be amazed on how many people just leave it on. In fact there are several little bt ad push systems,business cards, ect…

@mihawk90 I remember seeing a toggle in the in location settings can allows you to keep the bluetooth off but still have the device do a brief scan from time to time to locate you. Maybe that would work if you just use the Pi as a beacon and once the phone locates it send through the phone all the commands like turning on lights and so on.

@BansheeHero My idea was not really locate something precisely in a room but maybe locate if something is in the room. I guess it can be done some kind of calibration for this system using decibels in the signal.

Everything cool and nice but Bluetooth turned on in the phone all the time …


Testing for presence is easily done with this and you would want to calibrate for few things:

  • Consecutive findings (A single appearance could be passing through a room)
  • Bouncing of the signal (surface of 12cm can bounce the signal, so doors work, but dog will not block a signal from another room)
  • setting up two beacons in one room with planned placement can eradicate pretty much all normal outliers.

I’m down! Please keep me in the loop!

First thought was narrow band Lidar or MEM type sensors. BT will work great for now!