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Can I use an RFID reader and card to activate lights? Answered

I was thinking of putting some string lights around the top edges of my room. Near the entrance, I want to wall mount an RFID reader in an enclosure so that when I wave the card in front of it, the lights would toggle on or off. I was also considering putting a second reader near my bed so that at night I could turn the lights off while sitting in bed. I would really like some help on how to do this because I don't have a clue on how to allow the reader to control the lights. Also, the lights will probably be ones that plug into a normal outlet, just in case anybody was wondering.


I agree with lemonie, an RFID is expensive and complex overkill unless you want different lighting setups for different RFID tags.

If you want a light that will go on or off with a wave of a card (or something) over a sensor then either a simple IR proximity sensor (like these) that you just wave your hand over. They're pretty simple to hook up to a microcontroller.

If you want to wave a specific thing across a sensor then hall effect sensors would be a good option. Just wave a magnet nearby. There's a very fine Instructable on doing just that. (Though it only triggers the lights when a magnet is near, it would be trivial to make it a toggle switch.)

Thanks for the advice, will definitely stay away from the RFID readers as I didn't realize they would be that complicated to work with. I will probably use the hall effect sensors. Just a quick question though, if I want to use lights that plug into an outlet would I just strip the wire and tie into the wiring because that sounds like it could be a real fire hazard.

If you're using LED lights then you're fine. But if you're using lights that are powered from the house outlets then you'll need to use some kind of relay. This is because the circuit for the sensor runs at around 3.5-5 Volts DC while your outlets in your house tun at between 90-230 Volts AC (depending on what country you live in) and they tend to not react well when plugged directly into each other. I don't have much experience with them so I'll leave it to others to answer specific questions about using them.

This sounds like a terribly complicated and expensive way of turning lights on and off. How about using a magnetic switch instead, or do you really want the card? L