NFC Connectivity Technologies in IoT

Introduction

Near field communication, or NFC for short, is an offshoot of radio-frquency identification (RFID).
NFC is designed for use by devices within close proximity to each other.
All NFC types are similar but communicate in slightly different ways.
FeliCa is commonly found in Japan.

NFC Types

Passive devices contain information which is readable by other devices, however it cannot read information itself.
NFC tags found in supermarket products are examples of passive NFC.
Active devices are able to collect as well as transmit information.
Smartphones are a good example of active devices.

Working Principle

Works on the principle of magnetic induction.
A reader emits a small electric current which creates a magnetic field that in turn bridges the physical space between the devices.
The generated field is received by a similar coil in the client device where it is turned back into electrical impulses to communicate data such as identification number status information or any other information.
'Passive' NFC tags use the energy from the reader to encode their response while 'active' or 'peer-to-peer' tags have their own power source.

NFC Specifications

NFC's data-transmission frequency is 13.56 MHz.
NFC can transmit data at a rate of either 106, 212 or 424 Kbps (Kilobits per second).
Tags typically store between 96 and 512 bytes of data.
Communication range is less than 20 cms.

Modes of Operation

Lets two smartphones swap data

One active device picks up info from a passive one.

NFC device can be used like a contactless credit card.

NFC Applications