Simplest way to detect when a person is home

[SentinelAeon]

What would be the easiest way for my control system built around multiple ESP8266 modules to detect whether i am home or not. There are 3 things i never leave my house without: my keys, my wallet and my mobile phone. My keys are in keylock when i am home, my wallet is in a drawer and my mobile phone is near me generaly. Now i thought about simply using wifi or bluetooth signal meaning when i am connected to home wifi or system can detect me through bluetooth. But the thing is i generaly have all those things turned off on mobile phone, meaning wifi, bluetooth, data and location are all turned off unless i need them. So next thing i though about is to simply make a lever and if i hang my keys there it means i am home. But i like to keep my keys in keyhole. So, is there a way to have some passive keychain or maybe a card of sorts in wallet and then sensor somewhere in the apartment that will either detect it or not. I am looking for a solution as simple as possible that will not make me do something special everytime i leave or come home, otherwise i would just use a button and press it when i come home or leave.

 

[danadak]

Wallet in drawer, use a strain gauge or a LCD small resistive or capacitive touchscreen to detect its presence,
and interface to ESP8266....


Regards, Dana.

 

[rjenkinsgb]

Try this, it works well:

Home

ESP32 based indoor positioning system

espresense.com

 

[AnalogKid]

Or, making dana's idea even more simple, put the button you don't want to press under the wallet. Something low force such as a limit switch with a long-ish lever arm. 1 ounce force to activate, built-in return spring.

ak

 

[danadak]

Or something that does not take any significant height to activate, just use A/D
to detect R :

Regards, Dana.

 

[SentinelAeon]

Ok, that all seem nice ideas though it's very 1900 (not that anything is wrong with that, i love old and proven things). But, does tehnology offer something like a passive key chain of small size and then some kind of sensor connected to electricity near my door that would detect when the object is no longer detectable (without having to charge the keychain thingy) ?

 

[AnalogKid]

The problem is that the key chain fob or whatever probably needs a battery to emit a signal strong enough to be reliable throughout the apartment. Unpowered tags such as RFID don't have the range.

ak

 

[Nigel Goodwin]

RFID tag on the key fob, and an RFID scanner in the doorway - just as you have in a shop to prevent shop lifting You could then detect when you actually went out the door - or at least when your keys did

 

[rjenkinsgb]

The "ESPresence" setup I linked to earlier detects mobile phones by the bluetooth emission and identifies their approximate distance. It's free software you load on a suitable ESP32 based module.

You could have one in a central location, or for full home automation, one in each room - with the right config, you can tell which [registered] phones are in which room, or away.

Another option is the "Geofency" app; that is GPS based & can be configured to update a server when you move in or out of a certain radius from any of the locations you define in it.

 

[AnalogKid]

RFID tag on the key fob, and an RFID scanner in the doorway - just as you have in a shop to prevent shop lifting You could then detect when you actually went out the door - or at least when your keys did

Direction - ?

Being near the door but not going through it - ?

ak

 

[Nigel Goodwin]

Direction - ?

Being near the door but not going through it - ?

ak

Like in a shop - you need an RFID scanner to pass through - obviously you would need to exercise care, as hopping in an out is going to confuse things

 

[Beau Schwabe]

Life 360 App .... then have the ESP8266 read your email alert when you or another family member has left home or arrived home.

 

[SentinelAeon]

Bluetooth, wifi, gps is for now, not an option since i really have all those things toggled off unless i really need them. Heck, i am looking for a simple way to have my phone unreachable for calls (as in, phone is not reachable, not call reaches a phone and you have to wait till it stops ringing to continue its normal use) but keep network connectivity when i need to do some things online. I am trying to avoid sitting on this rollercoaster of stress that became the norm. I know it's wierd for most people and that is ok.

RFID tag sounds like a really awesome idea. My key is always in the keyhole when i am at home, always. And on the right side of the door i have plenty of space for a scanner, its about 30 centimeters (12 inches) away from keyhole. I am guessing that will be enough ? As far as code goes, i would probably do something along the line of scanning for RFID tag every minute and if scan fails for 15 scans in a row, it would be pretty safe to assume that i have left the home and can turn on certain things that i want to run while i am not at home. Its actualy just a few fans doing a few different things, not very loud but just loud enough that i wouldn't want them running while i am trying to fall asleep or meditate.

If this RFID tag could run without battery it would be great. Another option is some tag that has such low power consumption that it could run for a year - i have no problem charging once a year. Could someone maybe give me a link to aliexpress (or ebay/amazon if no other way) so i can see the dimensions and cost of such setup ?

One last idea i just got if all else fails. Knowing that i have keys in door at all time when i am home, and knowing that i have space on the right side of the door, i could just use laser, sensor, camera of sorts and point it at the place where keys are hanging from the door. Then it would simply be a matter of finding the easiest method to detect whether keys are there or they are not (in which case the sensor/laser/camera would actualy just see white wall)

 

[Grossel]

Direction - ?

Two sensors, each connected to the two inputs of a D-flipflop. The sensors have to be placed offset to each other so that one turn on and of a little later.
I know basic logic circuits is very 80-90'ish - but it's easy and should work pretty reliably.

Like this (just from a random web search)

https://www.researchgate.net/figure/21-Using-an-auxiliary-optocoupler-and-D-flip-flop-for-detecting-the-direction-of-the_fig13_335668624

 

[AnalogKid]

I agree that the logic is very well known, as optical encoders have been around since the 40's. But . . .

That is a much more rigidly controlled environment than an apartment doorway. RF radiation patterns can vary significantly based on nothing more than the water content in clothing. I think the two RF sensors would have to be inconveniently far apart, keeping in mind that both of them have to be inside the apartment.

ak

 

[Nigel Goodwin]

If this RFID tag could run without battery it would be great.

The whole point of RFID is there's no power required, it's powered remotely from the scanner - hence it's short range.

 

[danadak]

There are battery powered tags that can do up to 100 meters, some out to a Km :

http://alumni.media.mit.edu/~deva/papers/senseid.pdf

Long Range RFID | 433 mhz | 2.4 GHz

Long range RFID can work over 1 KM (0.62 miles) away. Usually used for safety or vehicle location, this technology can help first responders find people in buildings, provide female employees with a distress call, or save the life of an industrial worker.

skyrfid.com

Regards, Dana.

 

[rjenkinsgb]

Another option is some tag that has such low power consumption that it could run for a year - i have no problem charging once a year.

Keyfob - battery life over a year, works with espresense etc.

https://www.amazon.com/Blue-Charm-Beacons-Bluetooth-BC011-MultiBeacon/dp/B085XN9B7N

 

[AnalogKid]

Note that the more powerful the transmitter, the more difficult it will be to differentiate the signal strength difference between two relatively close together receivers (or their antennae).

ak

 

[Nigel Goodwin]

Bluetooth, wifi, gps is for now, not an option since i really have all those things toggled off unless i really need them.

Well don't

Turn BlueTooth ON, it doesn't use much power, and you could easily program an ESP32 to check if it's connected in the house or not, and detect your absence as when the BlueTooth is no longer connected.

I also turn things OFF on my phone, to extend battery life - but I leave BlueTooth ON as it then automatically connects to the Entertainment System in my car, allowing hands free use in the car. It doesn't cause any worthwhile degradation of battery life for the phone.