Questions tagged [rfid]
Radio Frequency IDentification
562 questions
0 votes
1 answer
79 views
NFC vs RFID: want to clarify the basic working principle
I am getting confused and overwhelmed by all the information about communication protocols etc. when I want to just clarify the basic physics. NFC: From what I can tell it's just basic inductive ...
0 votes
0 answers
104 views
RFID RC522 module not working with M5 Stick Plus 2 - no response, need help with setup
I'm having trouble getting an RFID RC522 module to work with my M5 Stick Plus 2 (ESP32). The module shows no response at all - no tag detection, no errors. My setup: M5 Stick Plus 2 (ESP32) RFID-...
1 vote
1 answer
71 views
UHF Tag in Pocket
I recently installed a UHF reader (AWID XM700 = 902-928 MHz, 5-7 ft reading distance) with intention to be able to have UHF keytags in the pocket that would trigger the reader before reaching the door ...
- 11
1 vote
1 answer
101 views
What type of tuning capacitor should I use with an RFID antenna?
I'm tuning from 134kHz to 125kHz, but I'm noob and clueless as to which physical cap types would be suitable/typical, and I'm assuming the cap needs to be able to handle ~400V from the datasheet max ...
- 13
0 votes
1 answer
156 views
Combining 13.56 MHz and 125 kHz in same reader - how I do to avoid interference?
I have a Mifare reader. I added a 125 kHz reader inside of it. So it become a multi-tech reader. I noticed however that the read range of both readers have greatly been decreased. Both antennas are of ...
1 vote
1 answer
178 views
125 kHz RFID long range tag?
So I have a garage door in my apartment complex that opens using a typical 125 kHz RFID tag, I'm wondering if there is a way to do this remotely from inside my car so I don't have to step out and tap ...
- 47
0 votes
0 answers
97 views
Need Help With Understanding an RFID Reader Circuit
I am trying to understand how the ASK 125KHz RFID reader on page 140 of this pdf works (4.0 ASK READER SCHEMATIC, Page 134 of the document): https://ww1.microchip.com/downloads/en/devicedoc/51115f.pdf ...
- 11
0 votes
1 answer
176 views
USB to RS232 open ended cable doesn't work whereas one with adapter works
I have this open-ended USB-RS232 cable USB-RS232-WE-1800-BT_0.0, another cable with adapter Startech ICUSB2321F, and this device PRDSTU251C that I want to connect with my PC. I can connect with the ...
- 11
1 vote
2 answers
159 views
How can I filter "unwanted" pulses coming from the AM demodulation on a microcontroller. The data is encoded in differential Manchester
EDIT AS ASKED: EM4095 Datasheet I use the read only configuration on a custom board. I am not using CLK/RDY as the bit rate is known, and reduces complexity (it doesn't offer much other than to ...
- 103
0 votes
1 answer
188 views
Calculating Inductance for RFID PCB Antennas (13.56 MHz) – Discrepancies in Results
I'm trying to calculate the inductance for various RFID PCB antennas (13.56 MHz). I used the tool from ST's Antenna Design tool (second image), but the results don't match the expected values shown in ...
- 29
1 vote
0 answers
40 views
On Off RFID Tag [closed]
Who can help or give an idea how to build a presence sensor using an RFID chip connected to a physical button. The idea is to use it like an wireless presence sensor that will use no electricity, but ...
0 votes
0 answers
54 views
Guidelines for signal routing near an RFID module array
The task at hand is connecting multiple RFID (13.56 Mhz) antennas in an array. Each antenna works on its own and access to it is by SPI. Only one antenna is active at a given moment. The technicals: ...
- 2,167
0 votes
1 answer
95 views
What does a far-field SPICE model for a 900 MHz antenna look like?
Without doing in-depth math for the EMI, I am trying to find a SPICE model for an antenna for a 900 MHz RFID system. My primary interest is circuits and not antennas per se, and using ADS and other ...
- 3,342
0 votes
0 answers
66 views
Easiest way to detect objects using DIY materials
I want to build a Scrabble board that detects tiles placed, mainly as a one off challenge and learning experience (i.e. not a commerical product). I haven't started building yet: I'm trying to work ...
- 101
0 votes
2 answers
231 views
RFID antenna measuring resonance frequency does not cover the theoretical value
I am looking to design a custom RFID antenna which operates at 13.56 MHz. I have designed the antenna using the NFC Design tool (link). Please see the parameters below: Figure 1: Antenna parameters ...
- 35