Cypherock NFC is a 15 mm * 16.16 mm add-on board with a versatile, near-field communications controller from NXP — the PN532 IC. NFC devices are used in contactless payment systems, electronic ticketing, and smartcards, but also in retail and advertising (inexpensive NFC tags can be embedded into packaging labels, flyers or posters).

Eg project - https://www.youtube.com/watch?v=eD3CZMPumCk&t

This board has full compliance with NFC Forum specifications which means that you will be able to use the full potential of NFC and its three distinct operating modes:

1. Card emulation
2. Read/Write
3. P2P

In other words, board can be set to behave either as an NFC reader, or a tag, or to establish a two-way connection with another NFC device.

The integrated firmware provides all NFC protocols for performing the contactless communication in charge of the modulation, data processing and error detection.

The board communicates with the target board MCU through the I2C interface, in compliance with NCI 1.0 host protocols (NCI stands for NFC controller interface). RST and INT pins provide additional functionality. The board uses a 3.3V power supply.

OPERATING MODES

NFC is designed to be intuitive for users. Communication between two devices is established in the simplest way possible — by bringing them close to each other. The standards are dictated by the NFC Forum. NFC frontends, like the one on this board, can operate in three distinct modes:

Card emulation mode — where NFC click behaves like a smartcard or a tag

In this mode, board emulates an NFC tag. It doesn’t initiate the communication, it only responds to an NFC reader. A typical application of the card emulation mode is how people use NFC in their smartphones to replace several cards, badges and tags at once (using the same phone for tollgate checkins, contactless payments and so on). Card emulation mode, however, is not useful just for smartphones, but for any type of portable device.

Read/Write — where the board behaves as an NFC Reader

Here, board communicates with a passive tag, smartcard, or an NFC device operating in card emulation mode. It can both read or write to a tag (although reading is a more common use-case because tags will often be write protected). In this mode, it generates the RF field, while a tag or card only modulates it.

Peer-to-peer — for more complex interactions

Peer-to-peer mode establishes a two-way communication channel between a pair of NFC-enabled devices. More complex interactions are possible in this mode, such as simplifying bluetooth pairing. When a user brings two devices close to each other, the two NFC chips establish a P2P connection and exchange data that facilitates the Bluetooth pairing, seamlessly — the user doesn’t have to type passwords or set configurations.

• Note that NFC is a subset of RFID working on 13.54 MHz. Therefore, an NFC IC can read/write ISO14443 RFID tags, and vice versa — compatible RFID readers can read NFC tags or NFC devices functioning in card emulation mode.