RF Tags and RFID

[zcacogp]

Chaps,

I'm new here. If I commit some grave social crime, I apologise in advance!

I am contemplating a project which would involve the use of RF Tags. The idea is that car doors should be unlocked automatically whenever an authorised driver comes near. The person has an RF tag on their person (possibly on their keyring) and the presence of this is detected when they approach the car, and it unlocks for them.

However, although I am fairly happy with simple electronics, I have never used RF tags, transmitters, recievers, detectors, responders or whatever else you may want to call them. I have an idea of buying transponders and a reciever, and the reciever output changes from Low to High (or vice versa) when a transponder is close to (within 2metres or so) of the reciever. The ability to programme in "New" transponders to be detected by the reciever would be desirable as well. (Ideally, any one transponder could be set so that it opens all the cars in the household as well, but this is not an essential requirement.) A small interface from the output of the reciever to the locking mechanism would be easily built, and away we go.

Trouble is, I don't know anything about RF tags. How much are they, where can I get them from, what part numbers are they? What sort of outputs do they have, and where can I get my hands on some (with circuit diagrams.)

Any help would be greatly appreciated!


Oli.

 

[stevez]

This post makes me wonder if someday soon we won't be wearing (externally or otherwise) an "rf tag" of some sort that is unique for each person. The tag would be used by all sorts of things for opening the car door, the front door of the house, admission to public buildings, use at the checkout counter, etc. That sounds neat - what scares me is the ability of big brother to track the individual.

 

[zcacogp]

Stevez,

Sure, that is a possibility. Given that I currently carry (at least) 3 seperate RF tags that I know of on a regular basis, it would surely be simpler if someone integrated the systems, and gave me one that would work train ticket barriers, open secure doors, turn my car immobiliser off etc etc etc.

However, I am less concerned with the long-term social aspects of this, and more interested in actually building such a system (after all, this is an electronics forum). Can anyone help?


Oli.

 

[kinjalgp]

May be these sites can help you.
www.rfid.org & http://www.discovercircuits.com/R/rfid.htm