# Sensors Overview - [Introduction](#section667413271505) - [Available APIs](#section7255104114110) ## Introduction The 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. **Figure 1** Sensor service framework ![](figures/en-us_image_0000001077724150.png) - 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. - Sensor Framework: manages sensor data subscription, creates and destroys data channels, and implements communication with the Sensor Service module. - 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. ## Available APIs **Table 1** APIs of the sensor framework

Function	Description	Parameter
int32_t GetAllSensors(SensorInfo *sensorInfo, int32_t count)	Obtains information about all sensors in the system. Return value: Returns 0 if the information is obtained; returns a non-zero value otherwise.	sensorInfo (not NULL): information about all sensors in the system count (not NULL): total number of sensors in the system
int32_t SubscribeSensor(int32_t sensorTypeId, SensorUser *user)	Subscribes to sensor data. The system will report the obtained sensor data to the subscriber. Return value: Returns 0 if the subscription is successful; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.
int32_t UnsubscribeSensor(int32_t sensorTypeId, SensorUser *user)	Unsubscribes from sensor data. The system will no longer report sensor data to the subscriber. Return value: Returns 0 if the unsubscription is successful; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.
int32_t SetBatch(int32_t sensorTypeId, SensorUser *user, int64_t samplingInterval, int64_t reportInterval)	Sets the data sampling interval and data reporting interval for the specified sensor. Return value: Returns 0 if the setting is successful; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor. samplingInterval: sensor data sampling interval, in nanoseconds reportInterval: sensor data reporting interval, in nanoseconds
int32_t ActivateSensor(int32_t sensorTypeId, SensorUser *user)	Enables the specified sensor that has been subscribed to. Return value: Returns 0 if the sensor is successfully enabled; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.
int32_t DeactivateSensor(int32_t sensorTypeId, SensorUser *user)	Disables an enabled sensor. Return value: Returns 0 if the sensor is successfully disabled; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.
int32_t SetMode(int32_t sensorTypeId, SensorUser *user, int32_t mode)	Sets the data reporting mode for the specified sensor. Return value: Returns 0 if the sensor data reporting mode is successfully set; returns a non-zero value otherwise.	sensorTypeId: ID of a sensor type user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor. mode: data reporting mode of the sensor

Function

Description

Parameter

int32_t GetAllSensors(SensorInfo **sensorInfo, int32_t *count)

Obtains information about all sensors in the system.

Return value: Returns 0 if the information is obtained; returns a non-zero value otherwise.

sensorInfo (not NULL): information about all sensors in the system

count (not NULL): total number of sensors in the system

int32_t SubscribeSensor(int32_t sensorTypeId, SensorUser *user)

Subscribes to sensor data. The system will report the obtained sensor data to the subscriber.

Return value: Returns 0 if the subscription is successful; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

int32_t UnsubscribeSensor(int32_t sensorTypeId, SensorUser *user)

Unsubscribes from sensor data. The system will no longer report sensor data to the subscriber.

Return value: Returns 0 if the unsubscription is successful; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

int32_t SetBatch(int32_t sensorTypeId, SensorUser *user, int64_t samplingInterval, int64_t reportInterval)

Sets the data sampling interval and data reporting interval for the specified sensor.

Return value: Returns 0 if the setting is successful; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

samplingInterval: sensor data sampling interval, in nanoseconds

reportInterval: sensor data reporting interval, in nanoseconds

int32_t ActivateSensor(int32_t sensorTypeId, SensorUser *user)

Enables the specified sensor that has been subscribed to.

Return value: Returns 0 if the sensor is successfully enabled; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

int32_t DeactivateSensor(int32_t sensorTypeId, SensorUser *user)

Disables an enabled sensor.

Return value: Returns 0 if the sensor is successfully disabled; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

int32_t SetMode(int32_t sensorTypeId, SensorUser *user, int32_t mode)

Sets the data reporting mode for the specified sensor.

Return value: Returns 0 if the sensor data reporting mode is successfully set; returns a non-zero value otherwise.

sensorTypeId: ID of a sensor type

user (not NULL): sensor subscriber that requests sensor data. A subscriber can obtain data from only one sensor.

mode: data reporting mode of the sensor