Introduction

Near field communication (NFC) is a form of contactless communication between devices or between a device and a chip/tag. Using NFC, a user can transfer/receive small amount information from a short distance (example, 10 cm).

Card-emulation mode, as the name suggests, makes the device behave like a contactless smart card. Using this mode we can develop virtual credit cards, debit cards, transit cards, and access cards. In this tip document, sample code from a Web app is shown for understanding.

Steps to create a simple web app for card emulation mode

Step-1: Add permissions

In the tizen-manifest.xml, the required privileges should be added:

http://tizen.org/privilege/nfc.cardemulation
http://tizen.org/privilege/nfc.common
http://tizen.org/privilege/application.launch
http://tizen.org/privilege/nfc.p2p
http://tizen.org/privilege/nfc.tag
http://tizen.org/privilege/nfc.admin

Step-2: Check if NFC adapter is supported o not

var adapter = tizen.nfc.getDefaultAdapter();

Step-3: Turning card emulation mode ON/OFF

To enable card emulation mode use:

adapter.cardEmulationMode = "ALWAYS_ON";

To disable card emulation mode use:

adapter.cardEmulationMode = "OFF";

Step-4: Turning on listener to receive data

To check the current card emulation mode, register a listener “modeListenerId”:

var modeListenerId = 0;
modeListenerId = adapter.addCardEmulationModeChangeListener(function(mode){
   if (mode === "ALWAYS_ON"){
      console.log("We are ready to go now");
}
});

Step-5: Check if listener detects expected NFC element

To detect changes in an active NFC secure element, register a listener “aseListenerId”:

var aseListenerId = 0;
aseListenerId = adapter.addActiveSecureElementChangeListener(function(seType)
{
   console.log("Active secure element is " + seType);
});

Step-6: Event handler of NFC data exchange

To detect exchange of a NFC secure element transaction data, register a listener “transListenerId”:

var transListenerId = 0;
function onDetected(appletId, data){
   console.log("NFC secure element transaction detected. Application: " + appletId + ". Protocol data: " + data);
});
transListenerId = adapter.addTransactionEventListener("UICC", onDetected);

Step-7: Clearing up the resources used in card emulation

adapter.removeActiveSecureElementChangeListener(aseListenerId);
adapter.removeTransactionEventListener(transListenerId);
adapter.removeCardEmulationModeChangeListener(modeListenerId);
adapter.cardEmulationMode = "OFF";

Step-8: Running the example application

Please check the attached sample code.

For testing purpose, we have used an android app named NFC Reader (https://play.google.com/store/apps/details?id=se.anyro.nfc_reader) as the reader app.

The copywrite ownership of this "NFC Reader" belongs to Adam Nybäck (https://play.google.com/store/apps/developer?id=Adam+Nyb%C3%A4ck).

 In addition, we  deployed our example app in a Gear S2 to act as the emulated card.

Once we start the example app in gear S2 (after enabling NFC from settings), it shows the following message:

Fig 1: Start up view of card emulation mode

Then, when we try to read from the gear S2 using the NFC reader, it shows the following: 

Fig 2: Screenshot when NFC reader reads the tag

Useful references:

[1] https://developer.tizen.org/development/tutorials/web-application/tizen-...

[2] https://developer.tizen.org/dev-guide/2.4/org.tizen.tutorials/html/web/t...

[3] https://developer.tizen.org/dev-guide/2.4/org.tizen.web.apireference/htm...

[4] https://developer.tizen.org/dev-guide/2.4/org.tizen.web.apireference/htm...