NFC: Adding second ndef message

[Andreas48752]

Hi,

I would like to combine NFC - BLE pairing and launch app record. Naively I thought I would write the second data right after the first:

uint32_t ndef_msg_len = sizeof(m_ndef_msg_buf);
uint32_t availLen = ndef_msg_len;
      
// Encode NDEF message with Secure Simple Pairing OOB optional data - TK value.
err_code = nfc_ble_pair_msg_updatable_tk_encode(NFC_BLE_PAIR_MSG_BLUETOOTH_LE_SHORT,
                                                  &m_oob_auth_key,
                                                  NULL,
                                                  m_ndef_msg_buf,
                                                  &ndef_msg_len,
                                                  m_tk_group,
                                                  TK_MAX_NUM);

uint32_t len = ndef_msg_len;
availLen -= len;

/* Encode launchapp message into buffer */
err_code = nfc_launchapp_msg_encode(m_android_package_name,  // todo test start app and pairing
                                  sizeof(m_android_package_name),
                                  m_windows_application_id,
                                  sizeof(m_windows_application_id),
                                  (m_ndef_msg_buf+ndef_msg_len),
                                  &availLen);
ndef_msg_len = len+ availLen;

// Update NFC tag data
err_code = nfc_t2t_payload_set(m_ndef_msg_buf, ndef_msg_len);

But this does not work. Reader app (NFC Tools, Android) does recognize tag but with no NDEF data.

How do you do that?

Thanks (again)...

Andreas

[Jared]

Hi,

• Does the BLE pairing work?
• If you add APP_ERROR_CHECK(err_code) after line 22 and 26, does the function return any error codes?

Regards

Jared

[Andreas48752]

Hi,

I think I solved the issue. The encoding functions set MB and ME bits of ndef record. If I modify it that first record has only MB set and second record nothing set (nfc_launchapp_msg_encode decodes two records, so third record has ME set) then it seems ok.