NFC

Near Filed Communication

Is a short range high frequency wireless communication

technology

Low speed (106 to 424 kbps)

Low friction setup (no discovery, no pairing)

NFC is an extension of Radio frequency identification

(RFID) technology

- RFID is mainly used for tracking and identification by sending radio waves

2

What is NFC?

How NFC works?

Use NFC to read information from a tag

Use NFC to read peer to peer information

How NFC is used with Android?

NFC feature is available from Android 2.3 version

Android Ice Cream Sandwich 4.0 introduced a new peer-to-peer interaction model

• 0-click contact sharing• 0-click web page sharing• 0-click youtube video sharing

How to NFC?

Reading NDEF data from an NFC tag= Nfc Data Exchange Format

By design, NDEF data is dispatched to only one activity The type of the first NDEF record is used for dispatch The data container format for NFC

More onhttp://developer.android.com/reference/android/nfc/NdefMessage.html http://developer.android.com/reference/android/nfc/NdefRecord.html

Reading NDEF data

Different Dispatch Types

Reading NDEF data

Android Manifest

<intent-filter> <action android:name="android.nfc.action.NDEF_DISCOVERED" /> <category android:name="android.intent.category.DEFAULT" /> <data android:mimeType="text/plain" /></intent-filter>

Activity class onResume

@Override protected void onResume() { … if (NfcAdapter.ACTION_NDEF_DISCOVERED.equals(getIntent().getAction())) { NdefMessage[] messages = getNdefMessages(getIntent()); byte[] payload = messages[0].getRecords()[0].getPayload(); … }

How to use NFC reading within Java code

Writing NDEF data

Writing NDEF tags

String text; NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA,"text/plain".getBytes(), text.getBytes()); NdefMessage textMessage = new NdefMessage(new NdefRecord[]{textRecord}); Tag tag = getIntent().getExtra(NfcAdapter.EXTRA_TAG); Ndef ndef = Ndef.get(tag); ndef.writeNdefMessage(textMessage);

Writing Peer to Peer

Foreground Activities can register an NDEF payload for P2PpushRegister the payload in advanceadapter.enableForegroundNdefPush(this, ndefMessage);

Ice Cream Sandwich previewRegister interest in P2P in advance, push the payload livepublic interface NdefPushCallback {public NdefMessage createMessage();}adapter.registerForegroundNdefPush(this, callback);

Writing NDEF data

Sources

http://developer.android.com/guide/topics/connectivity/nfc/nfc.html#tag-dispatchhttp://static.googleusercontent.com/external_content/untrusted_dlcp/www.google.com/en//events/io/2011/static/presofiles/how_to_nfc.pdfhttp://www.jessechen.net/blog/how-to-nfc-on-the-android-platform/http://developer.android.com/reference/android/nfc/package-summary.html

Questions & (hopefully) Answers

String question = audience.getNextQuestion(); while (question != null && timeLeft.getValue() > 0) {

try { answer(question);

} catch (AnswerNotKnownException e) { MakeSomethingUp();LOG.warn("Missed one: " + question, e);

} question = audience.getNextQuestion();

timeLeft.update(); }

audience.thankForAttention();