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Minor doc update.

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Change-Id: I1d29adfccbdc196a145a2c2a044d63b00e5f788b
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Nick Pelly
2011-02-15 13:34:38 -08:00
parent 8db7a7bfad
commit 1df862a465
2 changed files with 63 additions and 50 deletions
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2
core/res/AndroidManifest.xml
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@@ -339,7 +339,7 @@
android:description="@string/permdesc_bluetooth"
android:label="@string/permlab_bluetooth" />
<!-- Allows applications to directly communicate over NFC -->
<!-- Allows applications to perform I/O operations over NFC -->
<permission android:name="android.permission.NFC"
android:permissionGroup="android.permission-group.NETWORK"
android:protectionLevel="dangerous"

111
docs/html/guide/topics/nfc/index.jd
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@@ -31,29 +31,33 @@ page.title=Near Field Communication
</div>
</div>
<p>Near Field Communication (NFC) is a set of short-range wireless technologies, similar to RFID.
It typically requires a distance of 4 cm or less and operates at 13.56mhz and at rates ranging
from 106 kbit/s to 848 kbit/s. NFC communication always involves an initiator and a target. The
initiator actively generates an RF field that can power a passive target. This enables NFC
targets to take very simple form factors such as tags, stickers or cards that do not require
power. NFC peer-to-peer communication is also possible, where both devices are powered.</p>
<p>Compared to other wireless technologies such as Bluetooth or WiFi, NFC provides much lower
bandwidth and range, but provides low-cost, un-powered targets and do not require discovery or
pairing. Users interact with NFC tags with just a tap. Targets can range in complexity. Simple
tags just offer read and write capabilities, sometimes with one-time programmable areas to make
the card read-only. More complex tags offer math operations, and have cryptographic hardware to
authenticate access to a sector. The most sophisticated tags contain operating environments,
allowing complex interactions with applets that are running on the tag.</p>
<p>An Android device with NFC hardware typically acts as an initiator. This mode is also known as
NFC reader/writer. The device actively looks for NFC tags and starts activities to handle them in
this mode. In Android 2.3.3, devices also have some limited peer-to-peer support.</p>
<p>Near Field Communication (NFC) is a set of short-range wireless technologies, typically
requiring a distance of 4cm or less. NFC operates at 13.56mhz, and at rates ranging
from 106 kbit/s to 848 kbit/s. NFC communication always involves an initiator and a target.
The initiator actively generates an RF field that can power a passive target. This
enables NFC targets to take very simple form factors such as tags, stickers or cards that do
not require power. NFC peer-to-peer communication is also possible, where both devices
are powered.
<p>
Compared to other wireless technologies such as Bluetooth or WiFi, NFC provides much lower
bandwidth and range, but enables low-cost, un-powered targets
and does not require discovery or pairing. Interactions can be initiated with just a tap.
<p>
An Android device with NFC hardware will typically act as an initiator when the screen is
on. This mode is also known as NFC reader/writer. It will actively look for NFC tags and start
activities to handle them. Android 2.3.3 also has some limited P2P support.
<p>
Tags can range in complexity, simple tags just offer read/write semantics, sometimes
with one-time-programmable areas to make the card read-only. More complex tags offer
math operations, and have cryptographic hardware to authenticate access to a sector.
The most sophisticated tags contain operating environments, allowing
complex interactions with code executing on the tag.
<h2 id="api">API Overview</h2>
<p>The {@link android.nfc} package contain the high-level classes to interact with the local
device's NFC adapter, to represent discovered tags, and to use the NDEF data format.</p>
<p>The {@link android.nfc} package contains the high-level classes to interact
with the local device's NFC adapter, to represent discovered tags, and to use
the NDEF data format.
<table>
<tr>
@@ -65,44 +69,52 @@ page.title=Near Field Communication
<tr>
<td>{@link android.nfc.NfcManager}</td>
<td>A high level manager class that enumerates the NFC adapters on this Android device. Since
most Android devices only have one NFC adapter, you can just use the static helper {@link
android.nfc.NfcAdapter#getDefaultAdapter()} for most situations.</td>
<td>A high level manager class that enumerates the NFC adapters on this Android device.
Since most Android devices only have one NFC adapter, you can just use the static helper
{@link android.nfc.NfcAdapter#getDefaultAdapter(Context)} for most situations.</td>
</tr>
<tr>
<td>{@link android.nfc.NfcAdapter}</td>
<td>Represents the local NFC adapter and defines the Intents that are used in the tag
dispatch system. It provides methods to register for foreground tag dispatching and
foreground NDEF pushing. Foreground NDEF push is the only peer-to-peer support that is
currently provided in Android.</td>
<td>Represents the local NFC adapter. Defines the intent's used to request
tag dispatch to your activity, and provides methods to register for foreground
tag dispatch and foreground NDEF push. Foreground NDEF push is the only
peer-to-peer support that is currently provided in Android.</td>
</tr>
<tr>
<td>{@link android.nfc.NdefMessage} and {@link android.nfc.NdefRecord}</td>
<td>NDEF is an NFC Forum defined data structure, designed to efficiently store data on NFC
tags, such as Text, URLs, and other MIME types. An {@link android.nfc.NdefMessage} acts as a
<td>NDEF is an NFC Forum defined data structure, designed to efficiently
store data on NFC tags, such as text, URL's, and other MIME types. A
{@link android.nfc.NdefMessage} acts as a
container for the data that you want to transmit or read. One {@link android.nfc.NdefMessage}
object contains zero or more {@link android.nfc.NdefRecord}s. Each NDEF Record has a type
such as Text, URL, Smart Poster, or any MIME type. The type of the first NDEF Record in the
NDEF message is used to dispatch a tag to an Activity.</td>
object contains zero or more {@link android.nfc.NdefRecord}s. Each NDEF record
has a type such as text, URL, smart poster, or any MIME data. The type of the
first NDEF record in the NDEF message is used to dispatch a tag to an activity
on Android.</td>
</tr>
<tr>
<td>{@link android.nfc.Tag}</td>
<td>Represents a passive NFC target. These can come in many form factors such as a tag, card,
FOB, or an even more complex device doing card emulation. When a tag is discovered, a {@link
android.nfc.Tag} object is created and wrapped inside an Intent. The dispatch system sends
the Intent to a compatible Activity <code>startActivity()</code>. You can use the {@link
<td>Represents a passive NFC target. These can come in many form factors such as
a tag, card, key fob, or even a phone doing card emulation. When a tag is
discovered, a {@link android.nfc.Tag} object is created and wrapped inside an
Intent. The NFC dispatch system sends the intent to a compatible actvitiy
using <code>startActivity()</code>. You can use the {@link
android.nfc.Tag#getTechList getTechList()} method to determine the technologies supported by
this tag and create the corresponding {@link android.nfc.tech.TagTechnology} object with one
of classes provided by {@link android.nfc.tech}.</td>
</tr>
</table>
<p>The {@link android.nfc.tech} package contains classes to query properties
and perform I/O operations on a tag. The classes are divided to represent different
NFC technologies that can be available on a tag.
<p>The {@link android.nfc.tech} package contains classes to query properties and perform I/O
operations on a tag. The classes are divided to represent different NFC technologies that can be
available on a Tag:</p>
@@ -117,7 +129,7 @@ page.title=Near Field Communication
<tr>
<td>{@link android.nfc.tech.TagTechnology}</td>
<td>The interface that all Tag Technology classes must implement.</td>
<td>The interface that all tag technology classes must implement.</td>
</tr>
<tr>
@@ -153,8 +165,8 @@ page.title=Near Field Communication
<tr>
<td>{@link android.nfc.tech.Ndef}</td>
<td>Provides access to NDEF data and operations on NFC Tags that have been formatted as
NDEF.</td>
<td>Provides access to NDEF data and operations on NFC tags that have been formatted as NDEF.
</td>
</tr>
<tr>
@@ -166,15 +178,15 @@ page.title=Near Field Communication
<tr>
<td>{@link android.nfc.tech.MifareClassic}</td>
<td>Provides access to MIFARE Classic properties and I/O operations. Not all Android devices
provide implementations for this class.</td>
<td>Provides access to MIFARE Classic properties and I/O operations, if this
Android device supports MIFARE.</td>
</tr>
<tr>
<td>{@link android.nfc.tech.MifareUltralight}</td>
<td>Provides access to MIFARE Ultralight properties and I/O operations. Not all Android
devices provide implementations for this class.</td>
<td>Provides access to MIFARE Ultralight properties and I/O operations, if this
Android device supports MIFARE.</td>
</tr>
</table>
@@ -191,12 +203,13 @@ page.title=Near Field Communication
</li>
<li>The minimum SDK version that your application can support. API level 9 only supports
limited tag dispatching with {@link android.nfc.NfcAdapter#ACTION_TAG_DISCOVERED}, and only
gives access to NDEF messages via the {@link android.nfc.NfcAdapter#EXTRA_NDEF_MESSAGES} extra.
No other tag properties or I/O operations are accessible. API level 10 adds comprehensive
reader/writer support, so you probably want to use this for more functionality.
<pre class="pretty-print">
&lt;uses-sdk android:minSdkVersion="9|10"/&gt;
limited tag dispatch via {@link android.nfc.NfcAdapter#ACTION_TAG_DISCOVERED},
and only gives access to NDEF messages via the {@link android.nfc.NfcAdapter#EXTRA_NDEF_MESSAGES}
extra. No other tag properties or I/O operations are accessible. You probably want
to use API level 10 which includes comprehensive reader/writer support.
<pre class="pretty-print">
&lt;uses-sdk android:minSdkVersion="10"/&gt;
</pre>
</li>