Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [rfid]

Radio Frequency IDentification

0
votes
0answers
18 views

Designing NFC PCB antenna in multi layer instead of usual 1 layer antenna

I'm working on a new NFC reader board with serious limitations in dimension of the board. This cause smaller antenna coil, which affect on range and power of antenna. My boss suggested to design coil ...
0
votes
0answers
26 views

Load modulation vs load modulation with subcarrier

With two inductively coupled coils, load modulation is used to transmit information from a receiving coil to a transmitting coil. Why is load modulation with subcarrier far more common than regular ...
1
vote
0answers
13 views

sparkfun SRTR is not reading UHF tags

I just bought my Sparkfun SRTR. I have followed the tutorials from Simultaneous RFID Tag Reader Hookup Guide. However, my serial port in Arduino is not reading any tags. I cant seem to figure out if ...
-1
votes
1answer
54 views

RFID for angle encoding

Can RFID be used as an alternative to e.g. non contact magnetic encoders? Suppose a 150 mm diameter steel disk submersed in seawater subject to violent movement. Is it possible to put e.g. 30 passive ...
-1
votes
0answers
31 views

How to build an RFID passive circuit in ADS?

I want to build/design an RFID passive circuit using ADS, for this I need an RFID tag and a RFID reader. Inside the tag, there will be the RF module which contains modulator, demodulator, rectifier, ...
0
votes
1answer
33 views

Antenna polarization and antenna directivity are the same?

I'm working on an RFID project, and looking for information about the antennas that I have to use, I have the following doubt: Antenna polarization and antenna directiivity are the same? Thanks!
1
vote
1answer
47 views

SPI: Receiving bytes from slave

For a couple of days I have been learning about SPI and decided to give it a go with 2 small devices. DEVICE 1: Atmega328p (MASTER) DEVICE 2: MFRC522 (SLAVE) As far as I understand: master sets SS ...
0
votes
0answers
45 views

Trying to find appropriate RF mixer

I am a grad student looking for a downconverting mixer, operating at ~900MHz. I am making a back-reflection data transmitter, similar to RFID. It needs to do the following: Mixer Params: LO_in = ...
0
votes
1answer
53 views

Why are inductively coupled RFID systems put in certain frequency bands when there are no EM waves used?

LF - 125 kHz HF - 13.56 MHz Those frequencies refer to the magnetic field that is used to induce a voltage in the transponder. Can the magnetic fields actually interfere with EM waves in the ...
1
vote
1answer
32 views

NFC/RFID device sending URL to NFC-enabled smartphone at 20-30cm

I am very new to this so please bear with me. I have read many questions but I haven't quite found a suitable one for what I would like to do. I would need a NFC/HF RFID device able to send an URL to ...
0
votes
3answers
63 views

RFID: Why is inductive coupling used instead of EM waves for LF and HF systems?

Is it because of antenna sizes? At 900 MHz a 1/2 dipole has a size of around 15 cm. That would be far higher for 125 kHz, so instead we use coils to power the transponder and use load modulation for ...
1
vote
1answer
27 views

How does electromagnetism factor into inductively coupled RFID systems

LF and HF RFID systems use inductive coupling to supply the tag with power. UHF RFID systems use antennas to send electromagnetic waves, the power supplied to the tag comes from the transmitted ...
0
votes
1answer
29 views

How to use Antenna to amplify RFID read range?

I'm using a RC522 with Arduino to test a RFID application but I want to amplifiy this range to read sort of 1-3m. I don't have experience with this so I want know if this is possible, or other ...
1
vote
0answers
55 views

difference between ISO 14443 vs ISO 18092 and collision detection

I have been studying about contactless payment specifications and protocols and I have few questions about them. Are ISO-14443 and ISO-18092 called NFC and RFID in general terms, or are they a ...
0
votes
1answer
16 views

Variations in RFID USB Serial reader detection distance by connected device

I have a RFID reader that sends the TAG information over USB serial. I have had some troubles with it in a product where the detection success rate changes alot depending on what the USB RFID tag is ...
11
votes
3answers
2k views

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 ...
0
votes
1answer
26 views

RFID 13.56, can you include a tab in the data string?

I have tried to find the answer by googling but I can't find anything about it. On a normal barcode you can include a tab \t in the datastring making it possible ...
1
vote
2answers
41 views

Can UHF rfid pass thorugh few layers of clothes in a smart shopping system?

I am working on a smart shopping system and would like to know if a UHF rfid signal can pass through few layers of clothes in a bag as multiple clothes would be present in a bag and system has to ...
0
votes
0answers
24 views

In the eyes of an RFID reader, is there any difference between the E4100 and E4305 125 kHz chip?

I'm looking to copy an RFID fob. I wasn't sure what frequency it is, but after taking apart one similar to the one I want to copy and checking the chip, on it was written "4100", which from my ...
1
vote
1answer
59 views

Alternative wireless technology for passive RFID tags

I am working on a project where I have 3 boxes and a RFID reader (mfrc522) attached at the bottom of each box. I keep my wallet/keys/etc in these boxes and a LCD screen displays what is in each box ...
-3
votes
2answers
106 views

Can you find what RFID frequency is used in a tag and then edit it? [closed]

A short background: my brother has membership at a gym that uses small RFID tags ("near field", I suppose, as you need to tap them against the spinning gate in order to open it) and after changing his ...
0
votes
1answer
36 views

SMPS Transformer affect RFID card

In my circuit, RFID card sometimes works sometimes not. it depends on how I put the card on RFID receiver. Usually it does not work when I put around the smps transformer. I guess SMPS transformer ...
1
vote
0answers
46 views

“MH” Markings on a MFRC522 RFID reader

I just bough 2 MFRC522 RFID reader from a different store. Both of them work well to read a standard 13.56 Mhz tags. However, one of them have "MH" marking while the other doesnt. The one with MH ...
0
votes
0answers
130 views

How to read an unknown RFID tag

So I need to read this RFID tag. I know that it works and I know it uses 13.56 MHz. Still I couldn't read it with available mobile applications. The same when I used Arduino with RFID readers. But I ...
0
votes
0answers
17 views

RFID Collision: assume there are 3 readers and multiple tags

In this example, there are two readers activated (dark green: interrogation range; light green: interference range). We can see that there is a tag (say tag A) in the interrogation range of a reader, ...
0
votes
1answer
148 views

Increase range of 125khz RFID Reader

Currently the range for my 125khz RFID reader is about 4 centimeters. I have opened it like below: Is there any way to increase the range to around 10 to 20 centimeters? For example, increasing the ...
-1
votes
0answers
36 views

RFID Key Fob Reader SIEMENS From Car 12 Volt to USB

I'am trying to transform an Rfid reader from Car to usb. From the wiring Page 77 on Renault-Megane-II-Service-Manual I can identify the power wire 2 and ground wire 4 and I know the reader receive a ...
0
votes
1answer
113 views

Can I control/read an RFID reader with an Android device or do I have to put an Arduino board between the two? [closed]

I want to develop and Android app the reads RFID tags. I am wondering if I can control the RFID reader directly with an Android device or do I have to put an Arduino board between the two. The RFID ...
0
votes
2answers
44 views

Passive RFID tag - link between size of antenna and read range (detailed)?

It is often said that the smaller the tag, the shorter the read range. Could somebody explain more technically in terms of radio engineering? For instance: why the Hitachi's U chip cannot achieve a ...
0
votes
1answer
17 views

RFID Tag, Xbee or Bluetooth Module

I am just trying to detect if an object is within 7-10 feet from my phone. What device would you recommend? I don't care where it is or anything I just need a way of detecting that that device is at ...
1
vote
0answers
31 views

RFID reader antenna matching

I am trying to connect a RFID reader chip to an W3113 antenna on PCB. As said in datasheets, the antenna pin of the reader chip has internal 50 ohm impedance and antenna W3113 also has 50 ohm ...
1
vote
0answers
57 views

Servo sometimes freezes when used with another servo and MFRC522 RFID reader

I have looked, Googled and researched all over by now and I have not been able to find anyone experiencing a similar issue to mine, so I thought now would be the time to ask my own question on SE. ...
0
votes
1answer
87 views

Repairing an RFID antenna? [closed]

I have an RFID antenna that seems to be on a custom PCB. The issue I have is that the antenna on one side works fine, but the other side does not. I'm not sure if it is even possible or worthwhile to ...
0
votes
0answers
36 views

Power consumption of RFID vs SD card

I am working on enhancing security of data on electronic passports using homomorphic cryptography. Obstacles I am facing in application of the solution I have came up with relate directly to available ...
0
votes
0answers
44 views

Proximity tracking using RFID

I would like to build a proximity tracking system. A a central unit small enough to fit on a key chain or necklace that would be able to detect as soon as a tagged object is farther away than a dozen ...
1
vote
1answer
36 views

RC522 board not working, red led is on

I have a RFID RC522 board that was working perfectly, until by mistake I tried to write it with a phone as if it was a RFID tag and now it stopped working, in the way that its led still turns on but ...
0
votes
1answer
46 views

What is a solution to representing bits physically? (on a cartridge, to be read by the cartridge holder… like a printer)

I am trying to recreate the sort of microchips that are on printer cartridges so that I can make cartridges that can have their data programmed and read? I only need to store 8 bits, so I was thinking ...
0
votes
0answers
101 views

Arduino NANO + MFRC522 + SD Card Module + RTC System

This might seem an old question. However quite recently my professor has assigned a project to me to develop a Attendance-cum-Access System for his Lab. The problem Statement is: "Develop a Arduino ...
0
votes
0answers
134 views

STM32F4 SPI interface MFRC522 Overrun problem

I have a problem regarding SPI communication between MF RC522 RFID reader and STM32F4 Discovery board. I'm hoping some of you have much more experience regarding this topic. So, basically I want to ...
2
votes
1answer
503 views

On board 13.56MHz RFID antenna design

I recently stumbled upon a two-in-one NFC key designed by N-O-D-E and was astonished. Although its original purpose is for security, I love the idea of using tact ...
0
votes
1answer
272 views

AVR ATmega328 with DWM1000

I recently asked about this over in the Arduino stack, but it was a broad question, and I have made progress and narrowed down the issues. I have two Arduino Nano's, each attached to a DWM1000. This ...
0
votes
0answers
37 views

Designing NFC/RFID PCB

I am building a prototype for a wireless medical sensor, and I use an Xbee for the communication between the sensor and the controller. My problem is pairing. The sensor is about the size of a ...
0
votes
0answers
28 views

Passive RFID for live tracking?

Is there a way if I have a paddock 2 km by 2 km I can find the location of my livestock, essentially live tracking their movement? I've thought of possibly giving them a passive RFID tag with ...
0
votes
1answer
40 views

Protection against EMI for an RFID reader

I've designed a base board for a Velleman VMA405 (13.56 MHz) RFID reader based on MFRC522 IC. But, due to interference from the base board (I'm assuming the oscillator), the reading range is limited ...
0
votes
0answers
28 views

CR95HF as tag using ISO15693

Can I use CR95HF NFC module as the tag! CR95HF+MCU(Arduino) will send the data to Mobile NFC reader. Can I use like this?
0
votes
0answers
14 views

Is writing success increased by using shorter EPC on RFID tags?

I am writing and reading EPCs (Electronic Product Code) on small RFID tags (3mm diameter), and writing or reading can be challenging (writing often fails when my hand shakes, possibly because the tag ...
3
votes
1answer
136 views

Anti-collision Capabilities of MFRC522

I'm a Computer Engineering student, and my full knowledge of RFIDs is limited to the research I have conducted thus far (mainly using this site). As such, there are still some general concerns I have ...
0
votes
0answers
36 views

Are there UHF RFID antennas with entirely different azimuth and elevation?

To improve UHF RFID reader's accuracy, I want antenna that has long, narrow reading field. So it needs to be directional and have vastly different azimuth and elevation. I stumbled upon few articles, ...
1
vote
2answers
46 views

How many clock impulses can a passive RFID get in 1 radio signal?Does it even have a CPU?

From what I've found so far, when scanning multiple passive RFID tags at once, collisions will occur so some collision avoidance algorithms like pure aloha and slotted aloha are probably used.What I ...
0
votes
1answer
161 views

Where is UNIQUE 125kHz protocol specified?

I am working on a RFID reader project and I can't find 125kHz UNIQUE tag specification (like listed in this TWN4 reader spec). I could easily find the datasheets for EM4100, EM4200, EM4102 tags. One ...