1

I am attempting to make a grid of RFID readers that can triangulate the position of a tag within their read range.

I am currently using MFRC522 readers connected to a Raspberry Pi 4 Model B (4gb) and reading using the SimpleMFRC522 Python library.

This is great in that it lets me easily read from & write to the tags that the readers can detect.

I would like to try to triangulate the relative position of a tag by using several readers to gauge signal strength from each one, with the intention of scaling up to have a grid of readers (or antennae connected to multiplexers) that can track the position of a tag as it is moved across a larger area (think a few feet across).

Is this possible using MFRC522 readers, or is this something that could be done with other readers or a specific chip connected to other antennas? I can't see any methods to return signal data from the SimpleMFRC522 library, just read & write methods.

Is there a command I can send to the reader to return this data?

3
  • 1
    Perhaps you can consider two grids: RFID reader and RF detector. Or one RFID reader with a servo, another RF detector also driven by servo.
    – tlfong01
    Aug 21 '20 at 3:15
  • 1
    Thanks for the suggestion! I am open to suggestions on how best to accomplish an accurate and fast tracking grid. Although given i want to scale it up cost is a consideration, and rc522 is very cheap to buy hence why i started there. Aug 21 '20 at 9:34
  • You are welcome. I am just brainstorming. I only started learning RFID reader, RF detector, and GPS sensor about a year ago and have only played RFID and GPS for perhaps less than 100 hours each. I have not played with RF detector yet, because I think it is not that useful for my current project. For SimpleMFRC522, I am just scratching the surface. So I will be glad that all can join in to learn together. Cheers.
    – tlfong01
    Aug 21 '20 at 9:41
1

Question

Can Rpi4B 4GB, using SimpleMFRC522, triangluate a tag read by a grid of MFRC522 RFID readers?


Answer

Part A - RFID Reader Triangulation

rfid reader

See Refs 1, 2

/ to continue, ...


Part B - RF Detector Triangulation

RF Detector

See Refs 3, 4


Part C - GPS Satellites Multiangulation

ublox GPS-RTK2 Board (10mm accuracy) - SparkFun


And you can use a GPS board to do not only triangulation, but with 2,500+ satellites to multiangulate, to 10mm accuracy.


gps 1


/ to continue, ...


References

(1) RC522 - THM3060 RFID Reader Q&A

(2) RC522 - THM3060 RFID Reader Chat

(3) AD8632 - How Can I read data from AD8361 RF Detector - Rpi SE 2020mar15

(4) AD8632 - DIY Rpi Triple Axis RF/EMF Detector using AD8362/AD8361 - Rpi SE 2020may21

(5) RFID Range Overview - What is the maximum read distance of RFID? - SkyRFID

(6) Real-time Locating System - Wikipedia

(7) ublox GPS-RTK2 Board (10mm accuracy) - SparkFun $220

(8) Neo uBlox Neo-8M GNSS Module Tests - tlfong01, Rpi SE, 2020jul01

/ to continue, ...


Appendices

/ to continue, ...


End of answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.