Near Field Communication (NFC) is a close-range wireless communication technology that's being embedded in recent smartphones. Communication between two NFC devices happens instantly when they are placed in close proximity ("touch", "tap"), without the need of any prior configuration, leading to innovative use cases.

How NFC works¶

NFC devices use an inductive field operating at 13.56 MHz to communicate.

One device emits the field using a loop antenna and is called the initiator. The other device - the target - receives the field with another loop antenna. The target can be directly powered by the field emitted by the initiator (this is the case for passive tags).

The initiator modulates the amplitude of the field at a rate between 106 kbit/s and 424 kbit/s and the target replies by modulating its antenna's impedance at the same rate, which can be detected by the initiator.

Use cases¶

Secure Payment

NFC is often publicized as a mean to transform your phone into a credit card or a transportation pass. There are actually many payment/transportation trials going on around the world, including Google Wallet in the US.

Smart Posters

A NFC smartphone can read "NFC tags", which are passive NFC objects that can be embedded in a poster or inside a magazine's page for instance. When you touch it, your phone can get a URL and redirect you to the corresponding website. It is pretty similar to the functionality 2D codes offer but without the hassle of having to open a scanning app and to take a picture of the code. A NFC tag can even be embedded in a business card: someone who collects the card can create a new contact within his phone instantly from the information contained in the tag.

Peer-to-Peer

Peer-to-peer (P2P) allows to transfer data between two NFC-enabled devices. For instance you can share an app, or a specific website with someone else easily. You can also switch a running video from a small screen (phone) to a bigger one (tablet/TV).

NFC (via tags or P2P) can also be used to establish another type of wireless communication between two devices (WiFi or Bluetooth).

NFC devices¶

NFC-capable Android devices include the Samsung Galaxy S III, Galaxy S2 (some models only), Galaxy Nexus, Nexus S, the Acer Liquid Express, the HTC One X...

For an extensive list of NFC-enabled devices please visit this Wikipedia page.

µNFC Stack¶

The µNFC stack for mbed allows you to control your device with your NFC-enabled smartphone. You just need to present your Android smartphone to your device to launch a configuration interface; change the configuration and touch the device back to apply the changes.

Getting Started¶

Adafruit offers an NFC starting kit that includes everything you need to start prototyping with NFC & mbed:

• NXP LPC1768 mbed
• A NXP PN532 breakout board
• A breadboard & a set of wires

To get started with this board visit the PN532 Breakout Board page. Check out the NFC mood lamp demo to see the sort of things that can be enabled with mbed & the µNFC framework.

If you are interested to find out more about NFC, join our mailing list to get more information: Join the mbed Mailing List