NRF52 pair to NRF52 using NFC RFID tag with MAC address

[zachtos]

I asked about if NRF52 can pair to eachother without a PN532, but sounds like no, it can only read RFID tags.

So, how about if at factory we make RFID sticker/tag that have the MAC address of the central NRF52 radio, and if the peripheral reads the RFID tag, it enters pairing mode and connects to said central, perhaps the central may need a button depressed ?

So to pair, hold button on the central, it will look for an advertising peripheral. Peripheral will not advertise unless it reads a valid RFID tag with MAC address of central. If the MAC address matches the central, it will be added to the central's whitelist.

Is this possible?

If so, any easy suggestion to write quick tags at factory, perhaps a simple script that has the NRF52 chip send it's address to the the PN532 and write the MAC address to tags in set location?

[Krzysztof Zaraska]

How about:

• put PN532 in the central
• place peripherial close to the central
• press button on central
• central's PN532 reads peripherial's MAC address etc.
• central's PN532 writes its MAC address etc. to the peripherial
• peripherial starts advertising or whatever

[endnode]

Sure, once you have at least one NFC reader you can do whatever (by read and write).

[zachtos]

So then how does the peripheral 'know' that it's MAC address was read by the PN532?
--otherwise if it can emulate RFID only, I don't see how it would know to ever begin advertising to connect to the central...

[endnode]

Sorry, I don't get the point of your architecture as I stopped at the point where you are trying to explain what should devices do but based on wrong assumptions (= that nRF52 can read other NFC tag without additional HW) and by mixing the technical terms. Could you rewrite your original question so it will be crystal clear what is your final HW set-up (or at least what are your priorities on that side) and what you want to achieve (what is minimal set of conditions the solution should meet). Then we can help you easily.

[endnode]

If you are asking how NFC tag emulation inside nRF52 FW knows that there is any communication happening then I believe there should be such hooks in NFC NDEF tag type 2 or 4 "stacks" provided by Nordic. If this is really must (normally you shouldn't care, simply advertise, let everyone connect only the right guy who got transferred some out-of-band information over NFC will be able to continue in secure communication, otherwise you can kick every connecting device out after while) then you can base your NFC protocol on some read operation and that will definitely trigger your app FW.

[Krzysztof Zaraska]

You get a callback when tag is read.

infocenter.nordicsemi.com/index.jsp