1# Sensor Overview<a name="EN-US_TOPIC_0000001092893507"></a> 2 3## Introduction<a name="section667413271505"></a> 4 5The pan-sensor service subsystem provides a lightweight sensor service framework. You can call APIs offered by this framework to query the sensor list, enable or disable a sensor, and subscribe to or unsubscribe from sensor data. The following figure shows the architecture of the lightweight sensor framework. 6 7**Figure 1** Sensor service framework 8 9 10 11- Sensor API: provides APIs for performing basic operations on sensors, including querying the sensor list, subscribing to or unsubscribing from sensor data, and executing control commands. This module makes application development simpler. 12- Sensor Framework: manages sensor data subscription, creates and destroys data channels, and implements communication with the Sensor Service module. 13- Sensor Service: interacts with the HDF module to receive, parse, and distribute data, manages sensors on hardware and sensor data reporting, and controls sensor permissions. 14 15## Available APIs<a name="section7255104114110"></a> 16 17**Table 1** APIs of the sensor framework 18 19<a name="table203963834718"></a> 20<table><thead align="left"><tr id="row173964834716"><th class="cellrowborder" valign="top" width="33.33333333333333%" id="mcps1.2.4.1.1"><p id="p20921103144918"><a name="p20921103144918"></a><a name="p20921103144918"></a>Function</p> 21</th> 22<th class="cellrowborder" valign="top" width="25.722572257225725%" id="mcps1.2.4.1.2"><p id="p109216317495"><a name="p109216317495"></a><a name="p109216317495"></a>Description</p> 23</th> 24<th class="cellrowborder" valign="top" width="40.94409440944094%" id="mcps1.2.4.1.3"><p id="p1192112316497"><a name="p1192112316497"></a><a name="p1192112316497"></a>Parameter</p> 25</th> 26</tr> 27</thead> 28<tbody><tr id="row4397198154712"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p11001322173912"><a name="p11001322173912"></a><a name="p11001322173912"></a>int32_t <strong id="b792815314396"><a name="b792815314396"></a><a name="b792815314396"></a>GetAllSensors</strong>(SensorInfo **sensorInfo, int32_t *count)</p> 29</td> 30<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p199227318499"><a name="p199227318499"></a><a name="p199227318499"></a>Obtains information about all sensors in the system.</p> 31<p id="p9922153110492"><a name="p9922153110492"></a><a name="p9922153110492"></a><strong id="b2922183114917"><a name="b2922183114917"></a><a name="b2922183114917"></a>Return value</strong>: Returns <strong id="b15367115154516"><a name="b15367115154516"></a><a name="b15367115154516"></a>0</strong> if the information is obtained; returns a non-zero value otherwise.</p> 32</td> 33<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p4922173116498"><a name="p4922173116498"></a><a name="p4922173116498"></a><strong id="b633817407478"><a name="b633817407478"></a><a name="b633817407478"></a>sensorInfo</strong> (not NULL): information about all sensors in the system</p> 34<p id="p18922931134919"><a name="p18922931134919"></a><a name="p18922931134919"></a><strong id="b8845650154711"><a name="b8845650154711"></a><a name="b8845650154711"></a>count</strong> (not NULL): total number of sensors in the system</p> 35</td> 36</tr> 37<tr id="row1839716854716"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p38874252376"><a name="p38874252376"></a><a name="p38874252376"></a>int32_t <strong id="b17835184513919"><a name="b17835184513919"></a><a name="b17835184513919"></a>SubscribeSensor</strong>(int32_t sensorTypeId, SensorUser *user)</p> 38</td> 39<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p14922113114914"><a name="p14922113114914"></a><a name="p14922113114914"></a>Subscribes to sensor data. The system will report the obtained sensor data to the subscriber.</p> 40<p id="p5922331114916"><a name="p5922331114916"></a><a name="p5922331114916"></a><strong id="b7756437172"><a name="b7756437172"></a><a name="b7756437172"></a>Return value</strong>: Returns <strong id="b37618371173"><a name="b37618371173"></a><a name="b37618371173"></a>0</strong> if the subscription is successful; returns a non-zero value otherwise.</p> 41</td> 42<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p17922183120490"><a name="p17922183120490"></a><a name="p17922183120490"></a><strong id="b383183812561"><a name="b383183812561"></a><a name="b383183812561"></a>sensorTypeId</strong>: ID of a sensor type</p> 43<p id="p8922193154917"><a name="p8922193154917"></a><a name="p8922193154917"></a><strong id="b15825101814564"><a name="b15825101814564"></a><a name="b15825101814564"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 44</td> 45</tr> 46<tr id="row6397138134713"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p6923143184914"><a name="p6923143184914"></a><a name="p6923143184914"></a>int32_t <strong id="b338673044313"><a name="b338673044313"></a><a name="b338673044313"></a>UnsubscribeSensor</strong>(int32_t sensorTypeId, SensorUser *user)</p> 47</td> 48<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p792383116495"><a name="p792383116495"></a><a name="p792383116495"></a>Unsubscribes from sensor data. The system will no longer report sensor data to the subscriber.</p> 49<p id="p139231531184912"><a name="p139231531184912"></a><a name="p139231531184912"></a><strong id="b1698214914415"><a name="b1698214914415"></a><a name="b1698214914415"></a>Return value</strong>: Returns <strong id="b20983690447"><a name="b20983690447"></a><a name="b20983690447"></a>0</strong> if the unsubscription is successful; returns a non-zero value otherwise.</p> 50</td> 51<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p178981446572"><a name="p178981446572"></a><a name="p178981446572"></a><strong id="b5189141634413"><a name="b5189141634413"></a><a name="b5189141634413"></a>sensorTypeId</strong>: ID of a sensor type</p> 52<p id="p178988410573"><a name="p178988410573"></a><a name="p178988410573"></a><strong id="b56761418164417"><a name="b56761418164417"></a><a name="b56761418164417"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 53</td> 54</tr> 55<tr id="row43981283476"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p992473112496"><a name="p992473112496"></a><a name="p992473112496"></a>int32_t <strong id="b16691194511438"><a name="b16691194511438"></a><a name="b16691194511438"></a>SetBatch</strong>(int32_t sensorTypeId, SensorUser *user, int64_t samplingInterval, int64_t reportInterval)</p> 56</td> 57<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p14924831124913"><a name="p14924831124913"></a><a name="p14924831124913"></a>Sets the data sampling interval and data reporting interval for the specified sensor.</p> 58<p id="p14924203134910"><a name="p14924203134910"></a><a name="p14924203134910"></a><strong id="b181731732463"><a name="b181731732463"></a><a name="b181731732463"></a>Return value</strong>: Returns <strong id="b417363104616"><a name="b417363104616"></a><a name="b417363104616"></a>0</strong> if the setting is successful; returns a non-zero value otherwise.</p> 59</td> 60<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p189243318494"><a name="p189243318494"></a><a name="p189243318494"></a><strong id="b4102102264610"><a name="b4102102264610"></a><a name="b4102102264610"></a>sensorTypeId</strong>: ID of a sensor type</p> 61<p id="p167364493594"><a name="p167364493594"></a><a name="p167364493594"></a><strong id="b930712416461"><a name="b930712416461"></a><a name="b930712416461"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 62<p id="p1692403115493"><a name="p1692403115493"></a><a name="p1692403115493"></a><strong id="b1866310191589"><a name="b1866310191589"></a><a name="b1866310191589"></a>samplingInterval</strong>: sensor data sampling interval, in nanoseconds</p> 63<p id="p392443174917"><a name="p392443174917"></a><a name="p392443174917"></a><strong id="b851892113817"><a name="b851892113817"></a><a name="b851892113817"></a>reportInterval</strong>: sensor data reporting interval, in nanoseconds</p> 64</td> 65</tr> 66<tr id="row439813812472"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p17925631194911"><a name="p17925631194911"></a><a name="p17925631194911"></a>int32_t <strong id="b12311455154316"><a name="b12311455154316"></a><a name="b12311455154316"></a>ActivateSensor</strong>(int32_t sensorTypeId, SensorUser *user)</p> 67</td> 68<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p1892583174920"><a name="p1892583174920"></a><a name="p1892583174920"></a>Enables the specified sensor that has been subscribed to.</p> 69<p id="p16925113119497"><a name="p16925113119497"></a><a name="p16925113119497"></a><strong id="b1190011547620"><a name="b1190011547620"></a><a name="b1190011547620"></a>Return value</strong>: Returns <strong id="b1690019543620"><a name="b1690019543620"></a><a name="b1690019543620"></a>0</strong> if the sensor is successfully enabled; returns a non-zero value otherwise.</p> 70</td> 71<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p59255313493"><a name="p59255313493"></a><a name="p59255313493"></a><strong id="b269629475"><a name="b269629475"></a><a name="b269629475"></a>sensorTypeId</strong>: ID of a sensor type</p> 72<p id="p1692517314499"><a name="p1692517314499"></a><a name="p1692517314499"></a><strong id="b1739417117716"><a name="b1739417117716"></a><a name="b1739417117716"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 73</td> 74</tr> 75<tr id="row123998813470"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p492513120494"><a name="p492513120494"></a><a name="p492513120494"></a>int32_t <strong id="b1612146204413"><a name="b1612146204413"></a><a name="b1612146204413"></a>DeactivateSensor</strong>(int32_t sensorTypeId, SensorUser *user)</p> 76</td> 77<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p12925143118492"><a name="p12925143118492"></a><a name="p12925143118492"></a>Disables an enabled sensor.</p> 78<p id="p5926031124914"><a name="p5926031124914"></a><a name="p5926031124914"></a><strong id="b13736235877"><a name="b13736235877"></a><a name="b13736235877"></a>Return value</strong>: Returns <strong id="b273720356714"><a name="b273720356714"></a><a name="b273720356714"></a>0</strong> if the sensor is successfully disabled; returns a non-zero value otherwise.</p> 79</td> 80<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p1692683112499"><a name="p1692683112499"></a><a name="p1692683112499"></a><strong id="b1452911411574"><a name="b1452911411574"></a><a name="b1452911411574"></a>sensorTypeId</strong>: ID of a sensor type</p> 81<p id="p1081949113"><a name="p1081949113"></a><a name="p1081949113"></a><strong id="b11188443178"><a name="b11188443178"></a><a name="b11188443178"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 82</td> 83</tr> 84<tr id="row939914814478"><td class="cellrowborder" valign="top" width="33.33333333333333%" headers="mcps1.2.4.1.1 "><p id="p11530101054411"><a name="p11530101054411"></a><a name="p11530101054411"></a>int32_t <strong id="b1999420216444"><a name="b1999420216444"></a><a name="b1999420216444"></a>SetMode</strong>(int32_t sensorTypeId, SensorUser *user, int32_t mode)</p> 85</td> 86<td class="cellrowborder" valign="top" width="25.722572257225725%" headers="mcps1.2.4.1.2 "><p id="p892633118493"><a name="p892633118493"></a><a name="p892633118493"></a>Sets the data reporting mode for the specified sensor.</p> 87<p id="p1927031114910"><a name="p1927031114910"></a><a name="p1927031114910"></a><strong id="b456216221484"><a name="b456216221484"></a><a name="b456216221484"></a>Return value</strong>: Returns <strong id="b12562112214811"><a name="b12562112214811"></a><a name="b12562112214811"></a>0</strong> if the sensor data reporting mode is successfully set; returns a non-zero value otherwise.</p> 88</td> 89<td class="cellrowborder" valign="top" width="40.94409440944094%" headers="mcps1.2.4.1.3 "><p id="p119277312492"><a name="p119277312492"></a><a name="p119277312492"></a><strong id="b19747144015816"><a name="b19747144015816"></a><a name="b19747144015816"></a>sensorTypeId</strong>: ID of a sensor type</p> 90<p id="p159271031184915"><a name="p159271031184915"></a><a name="p159271031184915"></a><strong id="b1367209917"><a name="b1367209917"></a><a name="b1367209917"></a>user</strong> (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.</p> 91<p id="p0927173154916"><a name="p0927173154916"></a><a name="p0927173154916"></a><strong id="b3914356101520"><a name="b3914356101520"></a><a name="b3914356101520"></a>mode</strong>: data reporting mode of the sensor</p> 92</td> 93</tr> 94</tbody> 95</table> 96 97
