Connectivity

Overview

The Connectivity API provides a set of APIs for communicating with local devices.

The current version of the Connectivity API includes support for Bluetooth and Near Field Communication (NFC) technologies. Bluetooth is a short-range (less than 100 meters) wireless technology. It has a reasonably high data transfer rate of 2.1 Mbit/s, which makes it ideal for transfering data between devices.

The Bluetooth API provides classes for controlling the local Bluetooth device, discovering devices in the local vacinity, discovering services provided by those devices, publishing services and both server and client sockets for L2CAP and RFCOMM protocols.

NFC is an extremely short-range (approx. 1 centimeter) wireless techonology and has a maximum transfer rate of 424 kbit/s. NFC is ideal for transfer small packets of data when two devices are touched together.

The NFC API provides APIs for interacting with NFC Forum Tags and NFC Forum Devices, including target detection and loss, registering NDEF message handlers, reading and writing NDEF messages to NFC Forum Tags, send tag specific commands. The API also provides client and server LLCP sockets.

Known Issues and Limitations

Bluetooth and S60 5.0/Symbian^1

The S60 5.0 SDK as shipped by Nokia does not include all the required header files and libraries to compile the bluetooth backend for Symbian. It contains a subset of the requires bluetooth library. There is a Bluetooth plugin available for the S60 3.2 SDK but it cannot be used since it will overwrite and damage part of the bluetooth support already present in the 5.0 SDK. As such, compiling QtMobility for Symbian/S60 5.0 not recommended until Nokia releases a S60 5.0/Symbian^1 bluetooth plugin. A bug has been opened about this issue: http://bugreports.qt.nokia.com/browse/QTMOBILITY-1660

NFC

The NFC API is only supported on Harmattan and Symbian^3 and the Qt Simulator. On Symbian^3 the API is fully functional. On the Qt Simulator only target detection and loss and tag access are support. On Harmattan the following features are NOT supported:

• Connectionless LLCP sockets (both client and server).
• Tag type specific access.

Examples

Some interesting examples for the API exist.

Example	Description
NFC Annotated URL	Displays URL along with caption text and an image from from an NFC tag containing a specially formated NDEF message.
Bluetooth Chat	A chat server and client using bluetooth.
Bluetooth Tennis	The classic game of Pong. Supports multiplayer over Bluetooth and touch-to-play functionality on devices that support NFC.
Bluetooth File Transfer	Transfer files between Bluetooth devices.
Bluetooth Scanner	Scan for Bluetooth devices.
NDEF Editor	Create NDEF messages using the NDEF records supported by the Connectivity API and save them to supported NFC Forum tags.
QML Bluetooth Tennis	The tennis game using a QML interface to the Bluetooth API. It must connect to an instance of the C++ Bluetooth Tennis game to play.
QML Bluetooth Scanner	A QML implementation of the Bluetooth device scanner.
QML Poster	A QML implementation of the NFC Annotated URL example.

Main Classes

NFC Classes

QDeclarativeNdefRecord	Implements the NdefRecord element in QML
QLlcpServer	NFC LLCP socket based server
QLlcpSocket	NFC LLCP socket
QML NdefMimeRecord Element	The NdefMimeRecord element represents an NFC MIME record.
QNdefFilter	Filter for matching NDEF messages
QNdefMessage	NFC NDEF message
QNdefNfcTextRecord	NFC RTD-Text
QNdefNfcUriRecord	NFC RTD-URI
QNdefRecord	NFC NDEF record
QNearFieldManager	Access to notifications for NFC events
QNearFieldTagType1	Interface for communicating with an NFC Tag Type 1 tag
QNearFieldTagType2	Interface for communicating with an NFC Tag Type 2 tag
QNearFieldTagType3	Interface for communicating with an NFC Tag Type 3 tag
QNearFieldTagType4	Interface for communicating with an NFC Tag Type 4 tag
QNearFieldTarget	Interface for communicating with a target device

Bluetooth Classes

QBluetoothServiceInfo::Alternative	Data type for Bluetooth Data Element Alternative attributes
QBluetooth	Contains functions and definitions related to Bluetooth
QBluetoothAddress	Bluetooth address
QBluetoothDeviceDiscoveryAgent	API for discovering nearby Bluetooth devices
QBluetoothDeviceInfo	Information about Bluetooth devices
QBluetoothLocalDevice	Access to local Bluetooth devices
QBluetoothServiceDiscoveryAgent	API for querying the services provided by a Bluetooth device
QBluetoothServiceInfo	Information about services
QBluetoothSocket	Bluetooth socket
QBluetoothTransferManager	Allows the application to send data objects to other devices. Currently implemented using OPP
QBluetoothTransferReply	Contains the data and headers for a request sent with QBluetoothTranferManager
QBluetoothTransferRequest	Holds a request to be sent with QBluetoothTransferManager
QBluetoothUuid	Bluetooth UUID
QL2capServer	L2CAP server
QRfcommServer	RFCOMM server
QBluetoothServiceInfo::Sequence	Data type for Bluetooth Data Element Sequence attributes

Qt Quick Elements

QML BluetoothDiscoveryModel Element	The BluetoothDiscoveryModel element provides access device and service scanning
QML BluetoothService Element	The BluetoothService element contains all the information available for a single bluetooth service..
QML BluetoothSocket Element	The BluetoothSocket element represents a single bluetooth client socket.
QML NdefFilter Element	The NdefFilter element represents a filtering constraint for NDEF message records.
QML NdefRecord Element	The NdefRecord element represents a record in an NDEF message.
QML NdefTextRecord Element	The NdefTextRecord element represents an NFC RTD-Text NDEF record.
QML NdefUriRecord Element	The NdefUriRecord element represents an NFC RTD-URI NDEF record.
QML NearField Element	The NearField element provides access to NDEF messages stored on NFC Forum tags.
QML NearFieldSocket Element	The NearFieldSocket element represents an LLCP socket.