Topic: timing issues with PN53x
There is often written in this forum about timing issues with other nfc-controler than the NXP PN532 and tag emulation.
Where do I get information about this "timings" to compare different nfc-controler?
Re: timing issues with PN53x
Hello,
The timing issues are only for ISO14443-4 emulation ("-4" is the key), in this standard the initiator allow target to reply a standard "Wait Time Extension" to delay the "real" reply.
In the PN532, an ISO14443-4 ("-4" is really important) emulation is hardwarely assisted, that means the chip (PN532) put some WTX (Wait Time Extension") until the host (PC) reply to the initiator command.
The PN533 (or deprecated PN531) does not have hardware-assistance to send WTX frames before the host reply... and the host is really "slow" compared to the NFC/RFID standard timings.
I hope you understand what i'm trying to explain, its not easy to understand when we starts in RFID/NFC.
Romuald Conty
Re: timing issues with PN53x
Thx for your explanation Mr. Conty!
I'm studying software engineering and write my bachelor thesis in nfc and tag emulation, and I'm also very interested in NFC and this technology.
I understand what you mean. I think I must have a look into ISO14443-x documents in our library on campus.
AFAIK this documents are very expensive.
Re: timing issues with PN53x
IMHO, these documents should be publicly available, BTW that's not the point...
You could try using usual search engine, or chineses ones, the document could be find on the web. You could also use a "final draft" which is nearly the release document and have all important information.
Romuald Conty