pdk/docs/guide/sensors.jd

page.title=Sensors
pdk.version=1.0
@jd:body

<div id="qv-wrapper">
<div id="qv">
<h2>In this document</h2>
<a name="toc"/>
<ul>
<li><a href="#androidSensorsInterface">Interface</a></li>
</ul>
</div>
</div>

<p>Android defines a user space C abstraction interface for sensor hardware. The interface header is defined in 
<code>hardware/libhardware/include/hardware/sensors.h</code>.
In order to integrate sensors with Android you need to build a shared library that implements this interface. 

The types of sensors currently supported by Android include:
<ul>
<li>Accelerometer</li>
<li>Magnetic Field</li>
<li>Orientation</li>
<li>Gyroscope</li>
<li>Light</li>
<li>Pressure</li>
<li>Temperature</li>
<li>Proximity</li>
</ul>
</p> 
 
<a name="androidSensorBuildingDriver"></a><h3>Building a Sensor Library</h3>
<p> To implement a Sensors driver, create a shared library that implements the interface defined in <code>sensors.h</code>. You must name your shared library 
<code>libsensors.so</code> so that it will get loaded from <code>/system/lib</code> at runtime. 
</p>

<p> The following stub file, <code>Android.mk</code>, ensures that <code>libsensors</code> compiles and links to the appropriate libraries:</p>

<pre>
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)

LOCAL_MODULE := sensors

LOCAL_PRELINK_MODULE := false

LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw

LOCAL_SHARED_LIBRARIES := liblog
# include any shared library dependencies

LOCAL_SRC_FILES := sensors.c

include $(BUILD_SHARED_LIBRARY)
</pre>
 
<a name="androidSensorsInterface"></a><h3>Interface</h3> 
 
 
<p><span class="lh3"><a name="androidDoxygenNote"></a></span> 
 
<p class="note"><strong>Note</strong>: This document relies on some Doxygen-generated content that appears in an iFrame below. To return to the Doxygen default content for this page, <a href="sensors.html">click here</a>.</p> 
 
 
<iframe onLoad="resizeDoxFrameHeight();" src="sensors_8h.html" scrolling="no" scroll="no" id="doxygen" marginwidth="0" marginheight="0" 
frameborder="0" style="width:100%;"></iframe>