Problem with init of ISO14443B2SR

[GoogleCodeExporter]

cf http://www.libnfc.org/community/post/4702

I tried this code:
  nfc_target ant[1];
  nfc_modulation nm = {
     .nmt = NMT_ISO14443B2SR,
     .nbr = NBR_106
  };
  nfc_initiator_list_passive_targets(pnd,nm,ant,1);
  printf("%s\n",nfc_strerror(pnd)); // print RF Transmission Error
also with this I receive error: RF Transmission Error
but with this code got Success.
  nfc_target ant[1];
  nfc_modulation nm = {
     .nmt = NMT_ISO14443B,
     .nbr = NBR_106
  };
  nfc_initiator_list_passive_targets(pnd,nm,ant,1);
  printf("%s\n",nfc_strerror(pnd)); // print Success

  nfc_target ant2[1];
  nfc_modulation nm2 = {
     .nmt = NMT_ISO14443B2SR,
     .nbr = NBR_106
  };
  nfc_initiator_list_passive_targets(pnd,nm2,ant2,1);
  printf("%s\n",nfc_strerror(pnd)); // print Success
Why I need to execute a nfc_initiator_list_passive_targets with NMT_ISO14443B?
Is it a bug? Is there another way to initiliatize the comunication with tag 
ISO14443B?

Original issue reported on code.google.com by yob...@gmail.com on 25 Aug 2013 at 11:07

[GoogleCodeExporter]

This is a known problem.
nfc_initiator_list_passive_targets() for ISO14443B is calling a polling command 
from the PN53x firmware which sets internal registers properly.

nfc_initiator_list_passive_targets() for ISO14443B2SR does not rely on such 
command in the firmware because there is no such command.
The problem is that it does not setup the internal registers properly, so 
nfc_initiator_list_passive_targets() for ISO14443B2SR works when following 
nfc_initiator_list_passive_targets() for ISO14443B but not alone.

To solve the issue some reverse-engineering is needed to understand how 
internal registers of PN53x should be prepared.

Original comment by yob...@gmail.com on 25 Aug 2013 at 11:11

• Changed state: Accepted

[GoogleCodeExporter]

Hello! Since there's no documentation at all, once the target is opened (thanks 
for the code) how to read/write ISO14443B2SR card data?

I see that with ISO14443A examples, there's a CRC, anticollision methods and 
transceive bits. This apply also with ISO14443B2SR?

A simple example would be great!!

This is my code (opens target and prints UID):

// To compile this simple example:
// $ gcc -o quick_start_example1 quick_start_example1.c -lnfc
// ./quick_start_example1

#include <stdlib.h>
#include <nfc/nfc.h>

void print_nfc_target(const nfc_target *pnt, bool verbose)
{
  char *s;
  str_nfc_target(&s, pnt, verbose);
  printf("%s", s);
  nfc_free(s);
}

int main(int argc, const char *argv[])
{
    nfc_device *pnd;
    nfc_target nt;

    // Allocate only a pointer to nfc_context
    nfc_context *context;

    // Initialize libnfc and set the nfc_context
    nfc_init(&context);
    if (context == NULL) {
      printf("Unable to init libnfc (malloc)\n");
      exit(EXIT_FAILURE);
    }

    // Display libnfc version
    const char *acLibnfcVersion = nfc_version();
    (void)argc;
    printf("%s uses libnfc %s\n", argv[0], acLibnfcVersion);

    // Open, using the first available NFC device
    pnd = nfc_open(context, NULL);

    if (pnd == NULL) {
      printf("ERROR: %s\n", "Unable to open NFC device.");
      exit(EXIT_FAILURE);
    }
    // Set opened NFC device to initiator mode
    if (nfc_initiator_init(pnd) < 0) {
      nfc_perror(pnd, "nfc_initiator_init");
      exit(EXIT_FAILURE);
    }

    printf("NFC reader: %s opened\n", nfc_device_get_name(pnd));

    nfc_target ant[1];
    nfc_modulation nm;
    nm.nmt = NMT_ISO14443B;
    nm.nbr = NBR_106;

    nfc_initiator_list_passive_targets(pnd,nm,ant,1);
    printf("%s\n",nfc_strerror(pnd)); // print Success

    nfc_target ant2[1];
    nfc_modulation nm2;
    nm2.nmt = NMT_ISO14443B2SR;
    nm2.nbr = NBR_106;

    int res = 0;
    int n = 0;
    res = nfc_initiator_list_passive_targets(pnd, nm2, ant2, 1);
    printf("%s\n",nfc_strerror(pnd)); // print Success

//    printf("Cart identifier: %s\n", nt.nti.nsi.abtUID);
    for (n = 0; n < res; n++) {
      print_nfc_target(&ant2[n], true);
      printf("\n");
    }

    // Close NFC device
    nfc_close(pnd);
    // Release the context
    nfc_exit(context);
    exit(EXIT_SUCCESS);
}

Original comment by tonn...@gmail.com on 5 Jan 2015 at 12:38