Datasheet

About the NDEF Format

NDEF (NFC Data Exchange Format)

The NFC Data Exchange Format (NDEF) is a standardised data format that can be used to exchange information

between any compatible NFC device and another NFC device or tag. The data format consists of NDEF Messages and

NDEF Records. The standard is maintained by the NFC Forum and is freely available for consultation but requires

accepting a license agreement to download (https://adafru.it/aSA).

The NDEF format is used to store and exchange information like URIs, plain text, etc., using a commonly understood

format. NFC tags like Mifare Classic cards can be configured as NDEF tags, and data written to them by one NFC

device (NDEF Records) can be understood and accessed by any other NDEF compatible device. NDEF messages can

also be used to exchange data between two active NFC devices in "peer-to-peer" mode. By adhering to the NDEF

data exchange format during communication, devices that would otherwise have no meaningful knowledge of each

other or common language are able to share data in an organised, mutually understandable manner.

Some helpful app notes and white papers relating to NDEF are listed below:

NFC Data Exchange Format (NDEF) Technical Specification (https://adafru.it/aSA) (requires accepting the license

terms)

NFC Record Type Definition (RTD) Specification (https://adafru.it/aSA) (requires accepting the license terms)

NXP White Paper - NFC Forum Type Tags (https://adafru.it/aSO)

NDEF Messages

NDEF Messages are the basic "transportation" mechanism for NDEF records, with each message containing one or

more NDEF Records.

NDEF Records

NDEF Records contain a specific payload, and have the following structure that identifies the contents and size of the

record:

Record Header (Byte 0)

The record header contains a number of important fields, including a 3-bit field that identifies the type of record that

follows (the Type Name Format or TNF):

Bit 7 6 5 4 3 2 1 0

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

[ MB ] [ ME ] [ CF ] [ SR ] [ IL ] [ TNF ]

[ TYPE LENGTH ]

[ PAYLOAD LENGTH ]

[ ID LENGTH ]

[ RECORD TYPE ]

[ ID ]

[ PAYLOAD ]