Multiple Rfid Tags

vvvv gamma question
1

Hello guys,

I need to explore some solution to track the presence of a multiple small Objects into a define space… Ideally passive sensor …

I was thinking about rfid tags first and Phidget devices that sounds nice.. but looking at the documentation, it doesnt seems to be able to get multiple tags at the same time, (Does not support Anti collision protocols)

Maybe rfid is not the better avenue… does anyone have an experience with such kind of project?

Thanks you! :)

2

I don’t know the details on how to do that yourself, but as I know there are two major approaches:

  1. Scanner approach - it tracks the closes rfid’s in range.
  2. Antennas approach - it’s bunch of boxes with antennas (like routers) and they track distance to each marker, it used for personnel tracking in case of fire etc.

Sounds like you need second approach, but I’m not aware of any cheap solution, I’ve been once to company witch does that, I think they say that they buy boxes and trackers on something like aliexpress so components should be available, but that’s about I know…

The web interface for that looks like a building plan with dots traveling on it…

Something like that I guess: https://www.zebra.com/us/en/products/rfid/rfid-readers/fx9600.html https://www.youtube.com/watch?v=vbVyMeNyIzE

3

for example this on from m5stack: U107 | M5Stack RFID-Lesegerät JRD-4035 UHF | Distrelec Schweiz

price is similar or a little bit more expensive than the phidgets reader. but its multitag and can be used together with an esp, m5stack device or arduino.

if you want multitag search for RFID UHF… basically you get multiple tags with those with one scan (although also not really at the same time but within a short timeframe)

whats the range you need to detect?

4

Thanks you both for those suggestion, The M5Stack device seems to be a good match for my purpose… The area in question will be 50 cm²

But An other question, the installation is a little game where you can stack little cube (2cm²) to built what ever you want… I need really small tag, and to be able to know what cube there using and also if they’re stack on top of each other… would it be difficult to get them all in that context ? The proximity of multiple tag is a problem or not ?

5

im afraid rfid isnt able to do that…even not with signal strength and some kind of triangulation. i think its difficult to do with passive cubes. if they need to be passive as an easy solution only markertracking comes to my mind… t

heres some research with specially modified rfid tags doing exactly what you need as i understand, but yes thats not an off the shelf solution: RFIBricks: Interactive building blocks based on RFID - National Yang Ming Chiao Tung University Academic Hub

also you might check out the lego smart brick (not passive)

6

Thank @elektromeier

That’s so cool the project… yes it exactly what I am looking for… but in deed not something that could be done from scratch…