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     7     Nokia Corporation - initial contribution.

     8 Contributors: 

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    10 <!DOCTYPE task

    11   PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

    12 <task id="GUID-4B709839-8EEF-4AD2-9868-9AF0176B1E5B" xml:lang="en"><title>Using

    13 Sensor Channels APIs</title><shortdesc>The Sensor Channel establishes a data exchange connection between

    14 the sensor framework and hardware using the sensor channel APIs.</shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody>

    15 <steps id="GUID-4DD07DEC-6017-4237-BE46-1D69E5FBD744-GENID-1-8-1-9-1-1-6-1-4-1-4-1-3-1">

    16 <step id="GUID-9A69E5AD-E938-4092-A8C2-CB65C37C8962-GENID-1-8-1-9-1-1-6-1-4-1-4-1-3-1-1"><cmd>Include the library <b>SensrvClient.lib</b> in

    17 your <b>.mmp</b> file.</cmd>

    18 </step>

    19 <step id="GUID-4F637EBD-BD56-44FA-A984-E93CC4B2B3B6"><cmd>Include the following

    20 header files, as they are required for accessing sensor channels regardless

    21 of the channel type: </cmd>

    22 <info><ul>

    23 <li><p>sensrvchannel.h</p></li>

    24 <li><p>sensrvchannelinfo.h</p></li>

    25 <li><p>sensrvtypes.h</p></li>

    26 <li><p>sensrvchannelfinder.h</p></li>

    27 <li><p>sensrvdatalistener.h</p></li>

    28 </ul></info>

    29 </step>

    30 <step id="GUID-F5BC52B6-67DD-4F59-889B-C5DE4C69029B"><cmd>Retrieve details

    31 about the required sensor channel. For details. see <xref href="GUID-44FDDA27-1A5D-42B5-8DE0-D9E88EB75C93.dita">Querying

    32 for Sensor Channels</xref>.</cmd>

    33 </step>

    34 <step id="GUID-FBBD3A8B-F240-4DC0-B516-3A51FDD86A88"><cmd>Connect to the sensor

    35 by opening a connection with the sensor channel.</cmd>

    36 <substeps id="GUID-C9E5B9FC-C637-4DEB-AAAF-E38C6CD9A18A">

    37 <substep id="GUID-CA2CFF9C-3168-4060-AC39-8CB6FBA4BCA2"><cmd>Create an instance

    38 of <codeph>CSensrvChannel</codeph> and specify the instance of <codeph>TSensrvChannelInfo</codeph> returned

    39 by <xref href="GUID-5F108D03-C8A6-3EF9-B103-2E8916633602.dita#GUID-5F108D03-C8A6-3EF9-B103-2E8916633602/GUID-E58BAF1B-57AA-3E85-A4F9-8C6C29043FBD"><apiname>CSensrvChannelFinder::FindChannelsL()</apiname></xref>, as a parameter

    40 in the <codeph>NewL()</codeph> constructor.</cmd>

    41 <stepxmp><codeblock xml:space="preserve"> CSensrvChannel* sensorChannel;

    42  sensorChannel = CSensrvChannel::NewL(channelInfoList[0]);// channelInfoList is

    43 //   returned by the CSensrvChannelFinder::FindChannelsL()funtion</codeblock></stepxmp>

    44 </substep>

    45 <substep id="GUID-30E6033F-E316-4BDB-AF22-2369463DF709"><cmd>Open the sensor

    46 channel using <xref href="GUID-22DC917F-D833-3531-AB2D-A6E2D52EF844.dita#GUID-22DC917F-D833-3531-AB2D-A6E2D52EF844/GUID-277A4940-2E5E-3E8E-AB61-552CD2375F3C"><apiname>CSensrvChannel::OpenChannelL()</apiname></xref> function.</cmd>

    47 <stepxmp><codeblock xml:space="preserve">channel-&gt;OpenChannelL();</codeblock></stepxmp>

    48 </substep>

    49 </substeps>

    50 </step>

    51 <step id="GUID-7A414271-040C-4107-B047-9416747C66A6"><cmd>Perform any of the

    52 following operations:</cmd>

    53 <info><ul>

    54 <li><xref href="GUID-BA0D9DA9-3B54-4964-A4D6-9ADA4DEB7231.dita">Receive data from

    55 sensors</xref></li>

    56 <li><xref href="GUID-09E44FE5-6BEE-49FF-8BBF-CBB3C066EE10.dita">Listen for channel

    57 changes</xref></li>

    58 <li><xref href="GUID-83630B57-D842-4B60-8AF0-D2965251DE29.dita">Retrieve channel

    59 properties</xref></li>

    60 <li><xref href="GUID-0CA7F22E-59D7-4D65-9D6C-735E4E0F0454.dita">Set channel properties</xref></li>

    61 <li><xref href="GUID-E93EE459-8CF4-42A1-B06C-E78E56FD25A0.dita">Listen for channel

    62 property changes</xref></li>

    63 <li><xref href="GUID-60EE22AA-402D-4FC2-9AD1-B3AEF822E8DC.dita">Receive channel

    64 data based on conditions</xref></li>

    65 </ul></info>

    66 </step>

    67 <step id="GUID-61840C55-476C-4DC3-A946-A440330B9DE5"><cmd>Close the channel.</cmd>

    68 <info><codeblock xml:space="preserve">channel-&gt;CloseChannel();</codeblock><note type="important"> A

    69 channel must be closed when not required, as it reduces power consumption

    70 of the Symbian device. An open sensor channel keeps the device processor active

    71 each time data arrives. Therefore, the processor does not change to idle state

    72 even when the device user is not performing any operations on the device.</note></info>

    73 </step>

    74 </steps>

    75 </taskbody></task>