Is there a passive chip that can do this?
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intro24 (
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February 28th, 2012
from iPhone
I’m trying to think of a technology that would allow me to communicate with a passive object (that is, doesn’t use electricity) no more than a meter away. I was thinking RFID or NFC but I don’t know enough about the two to say for sure. Any suggestions? Specifically I need to find a way to track a thin, passive device less than a meter from a powered device. Just so I know the position of the passive device relative to the powered one.
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3 Answers
Yes, it’s passive RFID tech. The range depends on the chip, some small ones you swipe right beside a usb reader, expensive ones work from several inches.
Yes… people steal credit card chip info up to 40 feet with that tech all the time.
Most descriptions of NFC I see are not passive the way the RFID tech is. The ‘remote’ device will be powered and it has some smarts in it like a phone or tablet, and it will have some protocols that it will notice and respond to. They be able to communicate both ways and handle a lot more information than and RFID.
An RFID rig can typically only send from the ‘remote’ to a surveying host a small amount of information usually a unique identifier. There isn’t any real info transfer from host to remote except a signal that has the right characteristics (and enough power) to trigger the response.
NFC has a big security advantage because the powered smarts can do enough processing so it can refuse to respond unless given the right security handshakes.
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