Course Overview

What is NFC? An Introduction to NFC Tags, Cards, and Readers

Introduction

Tag Counter Game App

Set up a React Native NFC iOS and Android App

An Introduction to the React Native NFC Module Library

How to Build an iOS NFC Tag Scanner App With React Native

How to Build an Android NFC Tag Scanner App With React Native

App1 Conclusion

Tag-Counter Game App

Tap-And-Go App

How to Code an NDEF Message With the NFC Tools App

A Deep Dive Into NDEF and NdefRecord to Share Data via NFC

Tap-And-Go Project Setup With React Native and NFC Manager

How to Read NFC Tags and Write NDEF Data With NfcManager

How to Build a Website NFC Tag And Use Deep Linking With NFC

App2 Conclusion

Tap-And-Go  App

NFC Pokemon App

The User Flow of an NFC Tag Reader and Writer App

Intro to Type 2 NFC Tags: Read and Write NFC Tags With React

How to Sign and Verify NFC Data With React Native and elliptic

How to Add Memory Protection to NFC Tags For Copy Protection

App3 Conclusion

NfcPokemon  App

react

react-native

react-native-elements

react-native-nfc-manager

react-native-paper

## What we will cover in this course

First, I will provide an overview of NFC technology, so you can understand basic concepts and terms. After that, we will build three apps throughout this course.

### App 1: Tag Counter

![image](https://user-images.githubusercontent.com/10307875/148626752-38646752-bb16-4db2-8324-9fc19efdef04.png)

App 1 is a game app to count how much time a user needs to scan five NFC tags. You will learn:
- how to properly set up an NFC project 
- how to trigger NFC scanning
- the difference from iOS and Android regarding NFC feature

### App 2: Tap-and-Go

![image](https://user-images.githubusercontent.com/10307875/148627270-2dc43df8-8d5c-479d-8dd6-041b236d7009.png)

App 2 is about NFC Data Exchange Format (NDEF), which is the standard NFC data format supported by both iOS and Android. NDEF can be used for almost any NFC tag. We will build an NDEF reader-writer app, and you will learn:
- how to write specific NDEF URI into NFC tags 
- how to read NDEF URI and trigger corresponding actions, for example, opening an URL, making a phone call, or sending a message. 
- how to use deep linking with NFC tags.

### App 3: NFC Pokemon

![image](https://user-images.githubusercontent.com/10307875/148627203-562e742d-973e-406c-8e9e-a871ccdaf6d9.png)

App 3 dives into low-level NFC programming, which directly manipulates the NFC tag’s internal memory and uses proprietary NFC commands. 
The app we'll build is called "NFC Pokemon," which is a digital identity management platform. It can seal a specific Pokemon, for example, a Pikachu, into an NFC tag. 

When building this app, you will learn:
- how to use low-leve tag command to directly manipulate NFC tag's internal memory
- how to create digital signatures in React Native
- how to use proprietary password protection command for NXP NTAG 213 / 215

NFC technology is everywhere in our daily life, from transportation, access control, to payment system. However, understanding NFC is still a hard topic because of its wide technology landspace. 

So in this course, We will guide you from the simplest case like using common NDEF format, all the way to a complex digital identity management app which leverages some unique NFC features.

The newline Guide to NFCs with React Native

How to integrate NFC feature into your React Native app

How to handle the differences between Android and iOS regarding NFC feature

Understand NDEF and use it across iOS and Android

Understand low-level NFC programming and communicate with NFC tags directly

How to use asymmetric cryptography library with React Native

How to use password protection commands from NTAG 21x NFC tags

In this lesson, we will deep dive into NDEF.

NDEF stands for NFC Data Exchange Format. As the name implies, it is used as the standard way for NFC-enabled devices to exchange data with each other, especially NFC readers and NFC tags. 

Recall from the NFC specification overview diagram:

No matter which operation modes (top part), or Tag types (bottom), everything uses NDEF. For mobile operating systems, NDEF is fully implemented for both iOS and Android.

When talking about NDEF, there is a common confusion between two terms: 

s. From a software developer’s perspective, 

However, unlike most media containers, such as mp4, which has its own format to decouple from the actual data it contains, 

 is more like a logical concept. NdefRecord itself decides how to group several NdefRecords together to form one NdefMessage. We will see this idea in practice soon.

So, in short, the NdefRecord is the actual building block. 

In this diagram, one row represents 8 bits or 1 byte of data.

A NdefRecord has a fixed-length header (some people might call it 

 for short). After the fixed-length headers comes variable-length data. Conceptually, the data part of a NdefRecord could be further divided into three kinds: type, payload, and id. The type and payload are pretty self-explanatory. As for the id, it is used to let other NdefRecord identify themselves. Since it is complex but rarely used, we won’t talk too much here.

---
title: A Deep Dive Into NDEF and NdefRecord to Share Data via NFC
isPublicLesson: false
privateVideoUrl: https://fullstack.wistia.com/medias/up6iopevtq
---

In this lesson, we will deep dive into NDEF.

## What is NDEF

NDEF stands for NFC Data Exchange Format. As the name implies, it is used as the standard way for NFC-enabled devices to exchange data with each other, especially NFC readers and NFC tags. 

Recall from the NFC specification overview diagram:

![nfc-spec-overview](https://d2uusema5elisf.cloudfront.net/courses/newline-guide-to-nfcs-with-react-native/module_02/lesson_02.03/public/assets/nfc-spec-overview.png)

No matter which operation modes (top part), or Tag types (bottom), everything uses NDEF. For mobile operating systems, NDEF is fully implemented for both iOS and Android.

## NdefMessage vs. NdefRecord

When talking about NDEF, there is a common confusion between two terms: **NdefMessage** and **NdefRecord**. 

`NdefMessage` can be considered a container for `NdefRecord`s. From a software developer’s perspective, **NdefMessage is an array of NdefRecords**.

However, unlike most media containers, such as mp4, which has its own format to decouple from the actual data it contains, `NdefMessage` is more like a logical concept. NdefRecord itself decides how to group several NdefRecords together to form one NdefMessage. We will see this idea in practice soon.

So, in short, the NdefRecord is the actual building block. 

## NdefRecord structure

Here is the structure of a NdefRecord. 

![ndef-stucture](https://d2uusema5elisf.cloudfront.net/courses/newline-guide-to-nfcs-with-react-native/module_02/lesson_02.03/public/assets/ndef-structure.png)

In this diagram, one row represents 8 bits or 1 byte of data.

A NdefRecord has a fixed-length header (some people might call it `flags and TNF`, but we will call it `header` for short). After the fixed-length headers comes variable-length data. Conceptually, the data part of a NdefRecord could be further divided into three kinds: type, payload, and id. The type and payload are pretty self-explanatory. As for the id, it is used to let other NdefRecord identify themselves. Since it is complex but rarely used, we won’t talk too much here.

let’s observe the header part in more detail: 

-   The first bit is called `MB`, which refers to **message begin**. This NdefRecord is the first record for a new NdefMessade. 
-   The second bit called `ME`, which stands for **message end**, means this is the last record of the current NdefMessage. So, we can build NdefMessage by examining multiple NdefRecords sequentially. 
-   The third bit is `CF`, or **chunk flag**, which is used to group multiple payloads into one across multiple NdefRecords. In practice, it's rarely used.
-   The fourth bit is `SR`, which stands for the **short record**. This means the actual payload in the NdefRecord is less than 256, so we can use a single byte to represent the payload length to further reduce the total record size. On the other hand, a normal NdefRecord uses 32 bits or 4 bytes for the payload length. 
-   The fifth bit is `IL`, which tells whether this NdefRecord has ID or not. Again, ID is mainly used to let other NdefRecord identify themselves. We won’t talk too much about it since it’s rarely used. 
-   The final three bits are grouped together and called `TNF`, which stands for **Type Name Field**. It is an important one, essentially the **the category for the NdefRecord’s payload type**. So, to correctly identify the actual payload type for a NdefRecord, we should see both the TNF field and type field. 

Learn

The newline Guide to Building Your First GraphQL Server with Node and TypeScript

Teach

Amelia Wattenberger

Author of Fullstack D3

Community

The newline Guide to NFCs with React Native

Module 1: Introduction

Introduction:

Start Here

Lesson 1: (5:40)

Course Overview

Lesson 2: (10:37)

What is NFC? An Introduction to NFC Tags, Cards, and Readers

Module 2: Tag-Counter Game App

Lesson 1: (1:41)

Tag Counter Game App

Lesson 2: (11:10)

Set up a React Native NFC iOS and Android App

Lesson 3: (7:42)

An Introduction to the React Native NFC Module Library

Lesson 4: (10:03)

How to Build an iOS NFC Tag Scanner App With React Native

Lesson 5: (16:36)

How to Build an Android NFC Tag Scanner App With React Native

Lesson 6: (3:14)

App1 Conclusion

Module 3: Tap-And-Go App

Lesson 1: (1:40)

Tap-And-Go App

Lesson 2: (7:10)

How to Code an NDEF Message With the NFC Tools App

Lesson 3: (9:30)

A Deep Dive Into NDEF and NdefRecord to Share Data via NFC

Lesson 4: (11:46)

Tap-And-Go Project Setup With React Native and NFC Manager

Lesson 5: (18:19)

How to Read NFC Tags and Write NDEF Data With NfcManager

Lesson 6: (12:28)

How to Build a Website NFC Tag And Use Deep Linking With NFC

Lesson 7: (3:57)

App2 Conclusion

Module 4: NfcPokemon App

Lesson 1: (2:12)

NFC Pokemon App

Lesson 2: (6:51)

The User Flow of an NFC Tag Reader and Writer App

Lesson 3: (17:20)

Intro to Type 2 NFC Tags: Read and Write NFC Tags With React

Lesson 4: (17:29)

How to Sign and Verify NFC Data With React Native and elliptic

Lesson 5: (14:48)

How to Add Memory Protection to NFC Tags For Copy Protection

Lesson 6: (4:30)

App3 Conclusion

A Deep Dive Into NDEF and NdefRecord to Share Data via NFC