RFID and anti-collision algoritm

Using Arduino Project Guidance
1

Hi,
I would like some advice about my project idea:

I bought this board: PN532 NFC/RFID controller breakout board [v1.6] : ID 364 : Adafruit Industries, Unique & fun DIY electronics and kits
and these tags: 13.56MHz RFID/NFC Sticker - Classic 1K : ID 362 : Adafruit Industries, Unique & fun DIY electronics and kits

the board uses the PN532 chip, and according with the datasheet, (http://www.nxp.com/documents/short_data_sheet/PN532_SDS.pdf) collisions aren't managed, but it's possible by SW:

"The PN532 supports layers 2 and 3 of the ISO/IEC 14443 B Reader/Writer communication scheme, except anticollision. This must be implemented in firmware as well as upper layers."

I haven't the materials so I can't try it yet, but I would like to implement an anti-collision systems with arduino (I suppose that no more than two tags will be read at the same time).

Do you think is this idea impossible using those tags? Am I going to waste my time?

Thanks
Nicola

2

It will work for two tags.
Using the example library two tags will be repeatedly read alternatley.
Ive tried it.

3

Boardburner2:
It will work for two tags.
Using the example library two tags will be repeatedly read alternatley.
Ive tried it.

Do you mean I haven't to create a particular algorithm? :slight_smile:

4

No
I modified the readmyfaire example with a println statement.
Discovered that when several tags were placed on it it alternatley output two, i guess the two in the strongest part of the field.

It was unexpected and i think done by the firmware in the reader not the software.

Subsequently i read somewhere that two is the limin for that chip, wether its a firmware or hardware limitation i dont know.

I have no idea how to go about writing firmware for that chip, the whole protocol is baffling to me.

5

okk, perfect!
Thanks! :slight_smile:

6

That was just th uid though, i have yet to try readin writing data