Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [nfc]

Near Field Communications - In antennae theory Far Field radiation is that RF energy that gets transmitted, Near Field is the RF energy that typically does not propagate , unless it is intercepted by a special antenna. It is used to transmit signals over short distances without transmitting widely, it is used in wireless communications for very short ranges on the order of meters and is harder to intercept because you have to be close.

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What is this weird EMV pin on my credit card?

I recently got a Venmo card, which is my first card with contactless support. I was looking at the EMV pins and noticed a very weird design. In the middle of the ground pin, there is this long, thin pin extending into it that I've never seen…
Ian Carroll
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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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IC on Digikey is 5x more expensive than board containing same IC on Alibaba: How?

I built a prototype using an NFC board I bought from Alibaba for 1$ (https://www.alibaba.com/showroom/rfid-rc522.html). It claims to use the NXP MFRC522 IC, and if I look on the board the chip has that part number and even the little NXP logo. It…
MapleTronix
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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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Detecting object placement on a grid

I am working on an Android ADK project. I am looking for a way to detect the locations of chess pieces on a board (8x8). I was looking at things like NFC but It looks too expensive. Is there a different technology that I should consider. I need…
theJosh
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Does NFC drain power if tag is attached constantly?

I am not sure if it's a matter of NFC (Near Field Communication) standard or implementation of an NFC reader, but if a passive NFC tag is left attached to a reader, does that constantly drain power from it or not? I've noticed that when I try…
alexandroid
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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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How to add NFC to a cheap consumer product?

I want to add NFC (Near Field Communication) to a cheap consumer product with an existing microcontroller. I need to be able to pass a chunk of static data to a smartphone. I'd like to be able to pass dynamic data to the smartphone in both…
Toby Jaffey
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NFC reader long range antenna

As part of my university project I am trying to read NFC data (13.56MHz) at a longer range (~60 cm). I have already developed code that reads data from the card at close proximity, using libnfc and a standard USB based NFC reader. I am facing the…
Karma
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Questions about NFC's card emulation mode

NFC has a mode called "card emulation" in which it can communicate with an RFID reader because it acts as an RFID card. All the literature I have and the web searches I did only got me so far as with card emulation the device should at least "emit a…
Cadoc
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"Antenna matching networks for dummies"?

I'm working on a project where I'm building a custom NFC antenna that will be connected to a PN532 NFC controller. The antenna has already been designed (for 13.56 MHz) and built, the PN532 is also here, what's missing is the matching network…
Florian Echtler
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RFID (13.56MHz) GND plane over antenna

I dissasembled multiple RFID devices to study their design. The following reader attracted my attention: This is a four layer PCB, the anntenna seems to be 4-turn symetric and is layed out on the two internal layers of the PCB. You can see the…
sgt_johnny
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How do I determine what kind of proximity sensor / RFID hardware is in a device?

I have several objects in my pockets that do stuff when I put them near things: A token to disable a house alarm A Transport for London Oyster Card A security pass And in the not-too-distant-future, I wouldn't be surprised if my phone used NFC to,…
alexmuller
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I2C Slave ACK not driving down sufficiently

My I2C slave is not pulling down the bus all the way for the ACK. I have tried replacing 1.5k pullup with 10k pullup, but the ACK voltage remains the same (1.6V). System Voltage: 2.5V Master: STM32L151 Slave: NXP NT3H211 I have confirmed that the…
Chris Merck
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