In a project that my company is conducting we need an ISO14443A-4 connection where we will transfer application data using the ISO7816-4 specification. In order to develop and test the software we use an NFC evaluation board from the NFC chip vendor (NXP).
Here is the setup:
6131NFC (PCD) <---> ISO14443-4 Emulator (PICC, NXP PN512 chip)
The phone runs the Nokia "Detect external ISO14443 card" demo from the Wiki page. Using the phone on a DESfire SmartCard works well, so that side is okay. When I try it out on the my PICC emulator I get as far as the RATS command and the PICC answers this with a ATS response. It then seams as if the phone rejects the connection and starts the REQA process all over again, the phone only sends the 0x26 (REQA???) commands here after (I will need to remove the phone and touch again to get to the RATS once more). I have tried with different ATS responses, even with the one send by the DESfire card but with no luck. My guess is that the phone has some constraints regarding the UID and the ATS?
So my question is what is the procedure that 6131NFC uses when setting up a ISO14443A-4 connection?
I know what the ISO14443A-1 to 4 standard specify but there seams to be something "more" to the phones way of doing it. I have tried sniffing on the connection with the DESfire card and the only "funny" thing that I can see is that the phone makes heavy use of the HALT and DESELECT command before sending the first ISO7816-4 command (0xA4, Select application).
Has any one been into this technical stuff before; you Nokia specialists perhaps?