Turn on/off hall light with presence detection

[leto]

Hi all,

I need a solution to automatically turn a light on/off but with presence detection. So, It must work just when people carrying a RF device (RFID, etc) are coming. The constraints are:

-The RF emitter must be automatic. like a kind of key-chain. No need to press any button

-The light must be turned off when I´m in the home (the issue here is that the key-chain usually is hanged up next to the door, still activating the receptor and the light remain on

-There are 2 more apartments with its doors very near (less than 2 m). So, people go and back. They must not activate the light

I will appreciate any ideas

Thanks in advance

 

[betwixt]

RFID fits all the requirements. All RFID tags have unique serial numbers which you can read so including or excluding a tag at point of entry is just a case of validating its ID.
You can turn the light on by the introduction of a tag in to the sensor range, it can be turned off by the tag leaving the sensor range. If you want to turn it off while the tag is still present you have no option but to do it manually as nothing changes that could trigger the switch off condition.

RFID uses a near field to power the tag, no battery or other power source is needed at the tag itself and you can buy them in many shapes and sizes. I use credit card sized tags here but some users have discs (they are actually cattle ear tags but I don't tell the users that!) or key fob shaped ones.

Brian.

 

[leto]

Thank you Brian!

I uploaded a layout. I would like to turn on the light when people get out of the elevator (just because they have the keys in their pockets. They would not need to touch any reader. It should be transparent). he distance to my appartment is 7 m aprox. There, I would have the electronic to turn on-off the light.
So, even having a 7m range RF it would remain on, since my home is closer than that. Then, when they get out of the apartment the process should work in the opposite way..

thanks again.

 

[FvM]

RFID fits all the requirements.

Possibly. You should specify the requirements clearly. From what I have understood so far, you are asking for a long range (> 1m range) RFID system, means UHF or microwave band and battery powered tag.

 

[Externet]

If you can consider the human body as a moving IR emitter; these are widely available :

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