Datasheet

NDEF Records

The above example contains two records, both located in sector 1 (sector 0 contains the MAD).

Record 1

The first record on the card can be identified by looking at the first byte of block 4 in sector 1.

Every record on the Mifare card starts with the TLV Block (described above), and the first byte of the TLV Block (the

Tag Field) indicates that this is a NULL Block type (value 0x00). The second byte is the Length Field, and is 0. Since

there is no payload for this record (Length = 0), the third byte of the TLV block is not present (the Value Field).

This record was likely inserted when the card was first formatted to ensure that at least one record is present.

Record 2

The second record on the card starts at byte 0x02 of block 4 and continues into block 5.

Starting with the TLV Block data in the first two bytes, we can determine the following:

This indicates to us that the record contains an NDEF Message (value 0x03), and that the message is 17 bytes long

(0x11 in hexadecimal = 17 in decimal value). This means that our NDEF message is contained in the next 17 bytes

(04:04..05:04). The NDEF record can then be analysed as follows:

Block 61 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

Block 62 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

Block 63 00 00 00 00 00 00 7F 07 88 40 00 00 00 00 00 00 .......?@......

[ End of Memory Dump ]

Block 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Char Value

----- ----------------------------------------------- ------------

04 00 00 ..

Block 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Char Value

----- ----------------------------------------------- ------------

04 03 11 D1 01 0D 55 01 61 64 61 66 72 75 69 Ñ..U.adafrui

05 74 2E 63 6F 6D t.com

Byte(s) Value Description

------- ----- -----------

04:02 0x03 Field Type (0x03 = NDEF Message)

04:03 0x11 Length Field (17 bytes)