NFC type 4 Write

RE: NFC type 4 Write

Jørgen Holmefjord — Tue, 23 May 2017 18:26:15 GMT

Yes, the message buffer will be filled with old/garbage data. You need to use the NLEN field to get the valid data from buffer.

RE: NFC type 4 Write

Arepa — Tue, 23 May 2017 15:31:00 GMT

Hi Jørgen, I checked it, now I am receiving the data I wrote, but always on the first write I received corrupt data (always the same message possibly the last message default data on the buffer?)

update: I fixed it reading the m_ndef_msg_buf when it match with the expected data in NLEN field

RE: NFC type 4 Write

Jørgen Holmefjord — Tue, 23 May 2017 10:52:42 GMT

Hi,

When the NDEF buffer is updated (written), you will get a NFC_T4T_EVENT_NDEF_UPDATED event in nfc_callback. Typically, this will happen two times, as described in this answer. The data will be available in the NDEF message buffer given to the function nfc_t4t_ndef_rwpayload_set, which in the writable NDEF message example corresponds to m_ndef_msg_buf. The first two bytes of the buffer, the NLEN field, contains the length of the data.

Best regards,

Jørgen