Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rfid]

Radio Frequency IDentification

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Why does low frequency RFID have a short read range?

If I want to get the wavelength of a radio wave, I must divide the speed of light by the frequency? So having a 125 kHz RFID means an estimated 2km wavelength? If its wavelength is 2km long, why does this low frequency RFID have a short read…
Black
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Electronic pet-door access control - RFID

Inspired by projects such as the tweeting cat door and CATaLOG [sic] I’m wanting to add some form of automated access control to our pet door to control who can go in and out, when. (Full Disclosure: This is a reprint from my blog where I first…
Evan
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Why can't you put a plane under a trace antenna?

I'm working with RFID for the first time. All the app notes I've read show a separate region of PCB allocated for the trace antenna, with no planes above/below. I want to understand why this is, and if it's strictly necessary. I understand that the…
user2864293
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Options for short range distance determination between two objects

I have a project idea in mind, but it involves calculating the distance between two people. I've looked into Bluetooth, RFID, and NFC (unsure about this one), but none appear to offer the accuracy I would need (I am a novice at best, so I would…
Ryan
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How electronic price tag works?

Today I was in Tesco in my city and I saw something quite interesting, that was electronic price tag: I don't know how it happend, but on a parking I found this price tag in my basket beneath some old papers and leaflets... It was very late, so I…
SP5RFD
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How do you build your own RFID reader?

What's involved in building your own RFID reader? As you guys would know industrial RFID readers aren't cheap, how do you energise the antenna, then read back the output?
littlebirdceo
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Is there a difference between an NFC and RFID chip?

The other day, my friend said that he wants to write an app that uses the NFC chip on a phone to read pet microchips. I told him I was pretty sure that pet microchips don't use NFC, but he said he was pretty sure they did. So I hopped onto Wikipedia…
FirePenguin
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What's the purpose of such weird wiring inside this smart card?

Here's a scan of a stripped MIFARE Ultralight smart card That's some plastic film with (I assume aluminum) foil wiring acting as the antenna for both powering the chip and providing radio communications. Two things look suspicious. First, there's a…
sharptooth
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Best RFID Technology for long range detection?

I am considering building an RFID reader system that can monitor runners times in a foot race. I have read that there are three different types of RFID systems. LF, HF, and UHF. Which one would be best for this application? Has anyone had success…
PICyourBrain
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Punch a hole into a RFID card (125khz)

So I have this 125khz RFID card and I would like to punch a hole in it so I can have a thin string go through it, making my card to be able to hang from my neck. Though I have no experience in punching hole to any sort of card, not mentioning an…
Programer Beginner
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134.2 kHz RFID reader for Arduino

I am looking for an Arduino-compatible RFID reader supporting ISO 11784 & 11785, in order to read tags used for animals (mostly cats and dogs) identification. I found both RMD660 and and Sniffer Nano v2.0 from ITead Studio, but they are out of…
Wookai
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What can I do to increase passive HF RFID read range?

I am working on a prototype, one function of which is to detect whether an object is "in range" by a few cm. Right now I'm just using an Arduino and a cheap Mifare RC-522 kit that operates at 13.56 MHz: I've successfully gotten it to detect the…
JYelton
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Can I use a NFC ring as an Oyster card?

I've been looking into converting a MIFARE (Oyster card) into a ring. I found this NFC ring on kickstarter, will that work as an Oyster card? Or are they different technologies?
Coomie
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Read RFID tag with NFC reader?

Can I read passive RFID tag (125/134 kHz) with a NFC tag reader, like the one on Samsung Galaxy S3 ? If not, why: maybe because of the different frequency of the NFC reader (13,56 MHz)? Any way to to excite passive RFID tag with NFC reader?
Raffaele
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Long range RFID detection

I have a question about detecting RFID tags at long range. I understand there are LF, HF,and UHF RFID frequencies. I'm looking to detect a tag from a minimum distance of 2 meters (actually, 5 meters if possible). I would really like to us HF chips,…
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