SensorManager

See also:

• SensorEventListener
• SensorEvent
• Sensor

AXIS_MINUS_X

public static final int AXIS_MINUS_X

see remapCoordinateSystem(float, int, int, float)

Constant Value: 129 (0x00000081)

AXIS_MINUS_Y

public static final int AXIS_MINUS_Y

see remapCoordinateSystem(float, int, int, float)

Constant Value: 130 (0x00000082)

AXIS_MINUS_Z

public static final int AXIS_MINUS_Z

see remapCoordinateSystem(float, int, int, float)

Constant Value: 131 (0x00000083)

AXIS_X

public static final int AXIS_X

see remapCoordinateSystem(float, int, int, float)

Constant Value: 1 (0x00000001)

AXIS_Y

public static final int AXIS_Y

see remapCoordinateSystem(float, int, int, float)

Constant Value: 2 (0x00000002)

AXIS_Z

public static final int AXIS_Z

see remapCoordinateSystem(float, int, int, float)

Constant Value: 3 (0x00000003)

DATA_X

public static final int DATA_X

This constant was deprecated in API level 15.
use Sensor instead.

Index of the X value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 0 (0x00000000)

DATA_Y

public static final int DATA_Y

This constant was deprecated in API level 15.
use Sensor instead.

Index of the Y value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 1 (0x00000001)

DATA_Z

public static final int DATA_Z

This constant was deprecated in API level 15.
use Sensor instead.

Index of the Z value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 2 (0x00000002)

GRAVITY_DEATH_STAR_I

public static final float GRAVITY_DEATH_STAR_I

Gravity (estimate) on the first Death Star in Empire units (m/s^2)

Constant Value: 3.5303614E-7

GRAVITY_EARTH

public static final float GRAVITY_EARTH

Earth's gravity in SI units (m/s^2)

Constant Value: 9.80665

GRAVITY_JUPITER

public static final float GRAVITY_JUPITER

Jupiter's gravity in SI units (m/s^2)

Constant Value: 23.12

GRAVITY_MARS

public static final float GRAVITY_MARS

Mars' gravity in SI units (m/s^2)

Constant Value: 3.71

GRAVITY_MERCURY

public static final float GRAVITY_MERCURY

Mercury's gravity in SI units (m/s^2)

Constant Value: 3.7

GRAVITY_MOON

public static final float GRAVITY_MOON

The Moon's gravity in SI units (m/s^2)

Constant Value: 1.6

GRAVITY_NEPTUNE

public static final float GRAVITY_NEPTUNE

Neptune's gravity in SI units (m/s^2)

Constant Value: 11.0

GRAVITY_PLUTO

public static final float GRAVITY_PLUTO

Pluto's gravity in SI units (m/s^2)

Constant Value: 0.6

GRAVITY_SATURN

public static final float GRAVITY_SATURN

Saturn's gravity in SI units (m/s^2)

Constant Value: 8.96

GRAVITY_SUN

public static final float GRAVITY_SUN

Sun's gravity in SI units (m/s^2)

Constant Value: 275.0

GRAVITY_THE_ISLAND

public static final float GRAVITY_THE_ISLAND

Gravity on the island

Constant Value: 4.815162

GRAVITY_URANUS

public static final float GRAVITY_URANUS

Uranus' gravity in SI units (m/s^2)

Constant Value: 8.69

GRAVITY_VENUS

public static final float GRAVITY_VENUS

Venus' gravity in SI units (m/s^2)

Constant Value: 8.87

LIGHT_CLOUDY

public static final float LIGHT_CLOUDY

luminance under a cloudy sky in lux

Constant Value: 100.0

LIGHT_FULLMOON

public static final float LIGHT_FULLMOON

luminance at night with full moon in lux

Constant Value: 0.25

LIGHT_NO_MOON

public static final float LIGHT_NO_MOON

luminance at night with no moon in lux

Constant Value: 0.001

LIGHT_OVERCAST

public static final float LIGHT_OVERCAST

luminance under an overcast sky in lux

Constant Value: 10000.0

LIGHT_SHADE

public static final float LIGHT_SHADE

luminance in shade in lux

Constant Value: 20000.0

LIGHT_SUNLIGHT

public static final float LIGHT_SUNLIGHT

luminance of sunlight in lux

Constant Value: 110000.0

LIGHT_SUNLIGHT_MAX

public static final float LIGHT_SUNLIGHT_MAX

Maximum luminance of sunlight in lux

Constant Value: 120000.0

LIGHT_SUNRISE

public static final float LIGHT_SUNRISE

luminance at sunrise in lux

Constant Value: 400.0

MAGNETIC_FIELD_EARTH_MAX

public static final float MAGNETIC_FIELD_EARTH_MAX

Maximum magnetic field on Earth's surface

Constant Value: 60.0

MAGNETIC_FIELD_EARTH_MIN

public static final float MAGNETIC_FIELD_EARTH_MIN

Minimum magnetic field on Earth's surface

Constant Value: 30.0

PRESSURE_STANDARD_ATMOSPHERE

public static final float PRESSURE_STANDARD_ATMOSPHERE

Standard atmosphere, or average sea-level pressure in hPa (millibar)

Constant Value: 1013.25

RAW_DATA_INDEX

public static final int RAW_DATA_INDEX

This constant was deprecated in API level 15.
use Sensor instead.

Offset to the untransformed values in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 3 (0x00000003)

RAW_DATA_X

public static final int RAW_DATA_X

This constant was deprecated in API level 15.
use Sensor instead.

Index of the untransformed X value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 3 (0x00000003)

RAW_DATA_Y

public static final int RAW_DATA_Y

This constant was deprecated in API level 15.
use Sensor instead.

Index of the untransformed Y value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 4 (0x00000004)

RAW_DATA_Z

public static final int RAW_DATA_Z

This constant was deprecated in API level 15.
use Sensor instead.

Index of the untransformed Z value in the array returned by SensorListener.onSensorChanged(int, float)

Constant Value: 5 (0x00000005)

SENSOR_ACCELEROMETER

public static final int SENSOR_ACCELEROMETER

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing an accelerometer. See SensorListener for more details.

Constant Value: 2 (0x00000002)

SENSOR_ALL

public static final int SENSOR_ALL

This constant was deprecated in API level 15.
use Sensor instead.

A constant that includes all sensors

Constant Value: 127 (0x0000007f)

SENSOR_DELAY_FASTEST

public static final int SENSOR_DELAY_FASTEST

get sensor data as fast as possible

Constant Value: 0 (0x00000000)

SENSOR_DELAY_GAME

public static final int SENSOR_DELAY_GAME

rate suitable for games

Constant Value: 1 (0x00000001)

SENSOR_DELAY_NORMAL

public static final int SENSOR_DELAY_NORMAL

rate (default) suitable for screen orientation changes

Constant Value: 3 (0x00000003)

SENSOR_DELAY_UI

public static final int SENSOR_DELAY_UI

rate suitable for the user interface

Constant Value: 2 (0x00000002)

SENSOR_LIGHT

public static final int SENSOR_LIGHT

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing an ambient light sensor See SensorListener for more details.

Constant Value: 16 (0x00000010)

SENSOR_MAGNETIC_FIELD

public static final int SENSOR_MAGNETIC_FIELD

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing a magnetic sensor See SensorListener for more details.

Constant Value: 8 (0x00000008)

SENSOR_MAX

public static final int SENSOR_MAX

This constant was deprecated in API level 15.
use Sensor instead.

Largest sensor ID

Constant Value: 64 (0x00000040)

SENSOR_MIN

public static final int SENSOR_MIN

This constant was deprecated in API level 15.
use Sensor instead.

Smallest sensor ID

Constant Value: 1 (0x00000001)

SENSOR_ORIENTATION

public static final int SENSOR_ORIENTATION

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing an orientation sensor. See SensorListener for more details.

Constant Value: 1 (0x00000001)

SENSOR_ORIENTATION_RAW

public static final int SENSOR_ORIENTATION_RAW

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing an orientation sensor. See SensorListener for more details.

Constant Value: 128 (0x00000080)

SENSOR_PROXIMITY

public static final int SENSOR_PROXIMITY

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing a proximity sensor See SensorListener for more details.

Constant Value: 32 (0x00000020)

SENSOR_STATUS_ACCURACY_HIGH

public static final int SENSOR_STATUS_ACCURACY_HIGH

This sensor is reporting data with maximum accuracy

Constant Value: 3 (0x00000003)

SENSOR_STATUS_ACCURACY_LOW

public static final int SENSOR_STATUS_ACCURACY_LOW

This sensor is reporting data with low accuracy, calibration with the environment is needed

Constant Value: 1 (0x00000001)

SENSOR_STATUS_ACCURACY_MEDIUM

public static final int SENSOR_STATUS_ACCURACY_MEDIUM

This sensor is reporting data with an average level of accuracy, calibration with the environment may improve the readings

Constant Value: 2 (0x00000002)

SENSOR_STATUS_NO_CONTACT

public static final int SENSOR_STATUS_NO_CONTACT

The values returned by this sensor cannot be trusted because the sensor had no contact with what it was measuring (for example, the heart rate monitor is not in contact with the user).

Constant Value: -1 (0xffffffff)

SENSOR_STATUS_UNRELIABLE

public static final int SENSOR_STATUS_UNRELIABLE

The values returned by this sensor cannot be trusted, calibration is needed or the environment doesn't allow readings

Constant Value: 0 (0x00000000)

SENSOR_TEMPERATURE

public static final int SENSOR_TEMPERATURE

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing a temperature sensor See SensorListener for more details.

Constant Value: 4 (0x00000004)

SENSOR_TRICORDER

public static final int SENSOR_TRICORDER

This constant was deprecated in API level 15.
use Sensor instead.

A constant describing a Tricorder See SensorListener for more details.

Constant Value: 64 (0x00000040)

STANDARD_GRAVITY

public static final float STANDARD_GRAVITY

Standard gravity (g) on Earth. This value is equivalent to 1G

Constant Value: 9.80665

cancelTriggerSensor

public boolean cancelTriggerSensor (TriggerEventListener listener, 
                Sensor sensor)

Cancels receiving trigger events for a trigger sensor.

Note that a Trigger sensor will be auto disabled if TriggerEventListener.onTrigger(TriggerEvent) has triggered. This method is provided in case the user wants to explicitly cancel the request to receive trigger events.

createDirectChannel

public SensorDirectChannel createDirectChannel (MemoryFile mem)

Create a sensor direct channel backed by shared memory wrapped in MemoryFile object. The resulting channel can be used for delivering sensor events to native code, other processes, GPU/DSP or other co-processors without CPU intervention. This is the recommended for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz) and cares about sensor event latency. Use the returned SensorDirectChannel object to configure direct report of sensor events. After use, call SensorDirectChannel.close() to free up resource in sensor system associated with the direct channel.

createDirectChannel

public SensorDirectChannel createDirectChannel (HardwareBuffer mem)

Create a sensor direct channel backed by shared memory wrapped in HardwareBuffer object. The resulting channel can be used for delivering sensor events to native code, other processes, GPU/DSP or other co-processors without CPU intervention. This is the recommended for high performance sensor applications that use high sensor rates (e.g. greater than 200Hz) and cares about sensor event latency. Use the returned SensorDirectChannel object to configure direct report of sensor events. After use, call SensorDirectChannel.close() to free up resource in sensor system associated with the direct channel.

flush

public boolean flush (SensorEventListener listener)

Flushes the FIFO of all the sensors registered for this listener. If there are events in the FIFO of the sensor, they are returned as if the maxReportLatency of the FIFO has expired. Events are returned in the usual way through the SensorEventListener. This call doesn't affect the maxReportLatency for this sensor. This call is asynchronous and returns immediately. onFlushCompleted is called after all the events in the batch at the time of calling this method have been delivered successfully. If the hardware doesn't support flush, it still returns true and a trivial flush complete event is sent after the current event for all the clients registered for this sensor.

getAltitude

public static float getAltitude (float p0, 
                float p)

Computes the Altitude in meters from the atmospheric pressure and the pressure at sea level.

Typically the atmospheric pressure is read from a Sensor.TYPE_PRESSURE sensor. The pressure at sea level must be known, usually it can be retrieved from airport databases in the vicinity. If unknown, you can use PRESSURE_STANDARD_ATMOSPHERE as an approximation, but absolute altitudes won't be accurate.

To calculate altitude differences, you must calculate the difference between the altitudes at both points. If you don't know the altitude as sea level, you can use PRESSURE_STANDARD_ATMOSPHERE instead, which will give good results considering the range of pressure typically involved.

float altitude_difference = getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point2) - getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, pressure_at_point1);

getAngleChange

public static void getAngleChange (float[] angleChange, 
                float[] R, 
                float[] prevR)

Helper function to compute the angle change between two rotation matrices. Given a current rotation matrix (R) and a previous rotation matrix (prevR) computes the intrinsic rotation around the z, x, and y axes which transforms prevR to R. outputs a 3 element vector containing the z, x, and y angle change at indexes 0, 1, and 2 respectively.

Each input matrix is either as a 3x3 or 4x4 row-major matrix depending on the length of the passed array:

If the array length is 9, then the array elements represent this matrix

   /  R[ 0]   R[ 1]   R[ 2]   \
   |  R[ 3]   R[ 4]   R[ 5]   |
   \  R[ 6]   R[ 7]   R[ 8]   /

If the array length is 16, then the array elements represent this matrix

   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
   |  R[ 8]   R[ 9]   R[10]   R[11]  |
   \  R[12]   R[13]   R[14]   R[15]  /

getDefaultSensor

public Sensor getDefaultSensor (int type)

Use this method to get the default sensor for a given type. Note that the returned sensor could be a composite sensor, and its data could be averaged or filtered. If you need to access the raw sensors use getSensorList.

getDefaultSensor

public Sensor getDefaultSensor (int type, 
                boolean wakeUp)

Return a Sensor with the given type and wakeUp properties. If multiple sensors of this type exist, any one of them may be returned.

For example,

• getDefaultSensor(Sensor.TYPE_ACCELEROMETER, true) returns a wake-up accelerometer sensor if it exists.
• getDefaultSensor(Sensor.TYPE_PROXIMITY, false) returns a non wake-up proximity sensor if it exists.
• getDefaultSensor(Sensor.TYPE_PROXIMITY, true) returns a wake-up proximity sensor which is the same as the Sensor returned by getDefaultSensor(int).

Note: Sensors like Sensor.TYPE_PROXIMITY and Sensor.TYPE_SIGNIFICANT_MOTION are declared as wake-up sensors by default.

getDynamicSensorList

public List<Sensor> getDynamicSensorList (int type)

Use this method to get a list of available dynamic sensors of a certain type. Make multiple calls to get sensors of different types or use Sensor.TYPE_ALL to get all dynamic sensors.

NOTE: Both wake-up and non wake-up sensors matching the given type are returned. Check Sensor.isWakeUpSensor() to know the wake-up properties of the returned Sensor.

getInclination

public static float getInclination (float[] I)

Computes the geomagnetic inclination angle in radians from the inclination matrix I returned by getRotationMatrix(float, float, float, float).

getOrientation

public static float[] getOrientation (float[] R, 
                float[] values)

Computes the device's orientation based on the rotation matrix.

When it returns, the array values are as follows:

• values[0]: Azimuth, angle of rotation about the -z axis. This value represents the angle between the device's y axis and the magnetic north pole. When facing north, this angle is 0, when facing south, this angle is π. Likewise, when facing east, this angle is π/2, and when facing west, this angle is -π/2. The range of values is -π to π.
• values[1]: Pitch, angle of rotation about the x axis. This value represents the angle between a plane parallel to the device's screen and a plane parallel to the ground. Assuming that the bottom edge of the device faces the user and that the screen is face-up, tilting the top edge of the device toward the ground creates a positive pitch angle. The range of values is -π/2 to π/2.
• values[2]: Roll, angle of rotation about the y axis. This value represents the angle between a plane perpendicular to the device's screen and a plane perpendicular to the ground. Assuming that the bottom edge of the device faces the user and that the screen is face-up, tilting the left edge of the device toward the ground creates a positive roll angle. The range of values is -π to π.

Applying these three rotations in the azimuth, pitch, roll order transforms an identity matrix to the rotation matrix passed into this method. Also, note that all three orientation angles are expressed in radians.

getQuaternionFromVector

public static void getQuaternionFromVector (float[] Q, 
                float[] rv)

Helper function to convert a rotation vector to a normalized quaternion. Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized quaternion in the array Q. The quaternion is stored as [w, x, y, z]

getRotationMatrix

public static boolean getRotationMatrix (float[] R, 
                float[] I, 
                float[] gravity, 
                float[] geomagnetic)

Computes the inclination matrix I as well as the rotation matrix R transforming a vector from the device coordinate system to the world's coordinate system which is defined as a direct orthonormal basis, where:

• X is defined as the vector product Y.Z (It is tangential to the ground at the device's current location and roughly points East).
• Y is tangential to the ground at the device's current location and points towards the magnetic North Pole.
• Z points towards the sky and is perpendicular to the ground.

By definition:

[0 0 g] = R * gravity (g = magnitude of gravity)

[0 m 0] = I * R * geomagnetic (m = magnitude of geomagnetic field)

R is the identity matrix when the device is aligned with the world's coordinate system, that is, when the device's X axis points toward East, the Y axis points to the North Pole and the device is facing the sky.

I is a rotation matrix transforming the geomagnetic vector into the same coordinate space as gravity (the world's coordinate space). I is a simple rotation around the X axis. The inclination angle in radians can be computed with getInclination(float).

Each matrix is returned either as a 3x3 or 4x4 row-major matrix depending on the length of the passed array:

If the array length is 16:

   /  M[ 0]   M[ 1]   M[ 2]   M[ 3]  \
   |  M[ 4]   M[ 5]   M[ 6]   M[ 7]  |
   |  M[ 8]   M[ 9]   M[10]   M[11]  |
   \  M[12]   M[13]   M[14]   M[15]  /

Note that because OpenGL matrices are column-major matrices you must transpose the matrix before using it. However, since the matrix is a rotation matrix, its transpose is also its inverse, conveniently, it is often the inverse of the rotation that is needed for rendering; it can therefore be used with OpenGL ES directly.

Also note that the returned matrices always have this form:

   /  M[ 0]   M[ 1]   M[ 2]   0  \
   |  M[ 4]   M[ 5]   M[ 6]   0  |
   |  M[ 8]   M[ 9]   M[10]   0  |
   \      0       0       0   1  /

If the array length is 9:

   /  M[ 0]   M[ 1]   M[ 2]  \
   |  M[ 3]   M[ 4]   M[ 5]  |
   \  M[ 6]   M[ 7]   M[ 8]  /

The inverse of each matrix can be computed easily by taking its transpose.

The matrices returned by this function are meaningful only when the device is not free-falling and it is not close to the magnetic north. If the device is accelerating, or placed into a strong magnetic field, the returned matrices may be inaccurate.

getRotationMatrixFromVector

public static void getRotationMatrixFromVector (float[] R, 
                float[] rotationVector)

Helper function to convert a rotation vector to a rotation matrix. Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a 9 or 16 element rotation matrix in the array R. R must have length 9 or 16. If R.length == 9, the following matrix is returned:

   /  R[ 0]   R[ 1]   R[ 2]   \
   |  R[ 3]   R[ 4]   R[ 5]   |
   \  R[ 6]   R[ 7]   R[ 8]   /

   /  R[ 0]   R[ 1]   R[ 2]   0  \
   |  R[ 4]   R[ 5]   R[ 6]   0  |
   |  R[ 8]   R[ 9]   R[10]   0  |
   \  0       0       0       1  /

getSensorList

public List<Sensor> getSensorList (int type)

Use this method to get the list of available sensors of a certain type. Make multiple calls to get sensors of different types or use Sensor.TYPE_ALL to get all the sensors. Note that the Sensor.getName() is expected to yield a value that is unique across any sensors that return the same value for Sensor.getType().

NOTE: Both wake-up and non wake-up sensors matching the given type are returned. Check Sensor.isWakeUpSensor() to know the wake-up properties of the returned Sensor.

getSensors

public int getSensors ()

This method was deprecated in API level 15.
This method is deprecated, use SensorManager.getSensorList(int) instead

isDynamicSensorDiscoverySupported

public boolean isDynamicSensorDiscoverySupported ()

Tell if dynamic sensor discovery feature is supported by system.

registerDynamicSensorCallback

public void registerDynamicSensorCallback (SensorManager.DynamicSensorCallback callback)

Add a DynamicSensorCallback to receive dynamic sensor connection callbacks. Repeat registration with the already registered callback object will have no additional effect.

registerDynamicSensorCallback

public void registerDynamicSensorCallback (SensorManager.DynamicSensorCallback callback, 
                Handler handler)

Add a DynamicSensorCallback to receive dynamic sensor connection callbacks. Repeat registration with the already registered callback object will have no additional effect.

registerListener

public boolean registerListener (SensorEventListener listener, 
                Sensor sensor, 
                int samplingPeriodUs)

Registers a SensorEventListener for the given sensor at the given sampling frequency.

The events will be delivered to the provided SensorEventListener as soon as they are available. To reduce the power consumption, applications can use registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int, int) instead and specify a positive non-zero maximum reporting latency.

In the case of non-wake-up sensors, the events are only delivered while the Application Processor (AP) is not in suspend mode. See Sensor.isWakeUpSensor() for more details. To ensure delivery of events from non-wake-up sensors even when the screen is OFF, the application registering to the sensor must hold a partial wake-lock to keep the AP awake, otherwise some events might be lost while the AP is asleep. Note that although events might be lost while the AP is asleep, the sensor will still consume power if it is not explicitly deactivated by the application. Applications must unregister their SensorEventListeners in their activity's onPause() method to avoid consuming power while the device is inactive. See registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int, int) for more details on hardware FIFO (queueing) capabilities and when some sensor events might be lost.

In the case of wake-up sensors, each event generated by the sensor will cause the AP to wake-up, ensuring that each event can be delivered. Because of this, registering to a wake-up sensor has very significant power implications. Call Sensor.isWakeUpSensor() to check whether a sensor is a wake-up sensor. See registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int, int) for information on how to reduce the power impact of registering to wake-up sensors.

Note: Don't use this method with one-shot trigger sensors such as Sensor.TYPE_SIGNIFICANT_MOTION. Use requestTriggerSensor(android.hardware.TriggerEventListener, android.hardware.Sensor) instead. Use Sensor.getReportingMode() to obtain the reporting mode of a given sensor.

registerListener

public boolean registerListener (SensorEventListener listener, 
                Sensor sensor, 
                int samplingPeriodUs, 
                int maxReportLatencyUs)

Registers a SensorEventListener for the given sensor at the given sampling frequency and the given maximum reporting latency.

This function is similar to registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int) but it allows events to stay temporarily in the hardware FIFO (queue) before being delivered. The events can be stored in the hardware FIFO up to maxReportLatencyUs microseconds. Once one of the events in the FIFO needs to be reported, all of the events in the FIFO are reported sequentially. This means that some events will be reported before the maximum reporting latency has elapsed.

When maxReportLatencyUs is 0, the call is equivalent to a call to registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int), as it requires the events to be delivered as soon as possible.

When sensor.maxFifoEventCount() is 0, the sensor does not use a FIFO, so the call will also be equivalent to registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int).

Setting maxReportLatencyUs to a positive value allows to reduce the number of interrupts the AP (Application Processor) receives, hence reducing power consumption, as the AP can switch to a lower power state while the sensor is capturing the data. This is especially important when registering to wake-up sensors, for which each interrupt causes the AP to wake up if it was in suspend mode. See Sensor.isWakeUpSensor() for more information on wake-up sensors.

registerListener

public boolean registerListener (SensorEventListener listener, 
                Sensor sensor, 
                int samplingPeriodUs, 
                Handler handler)

Registers a SensorEventListener for the given sensor. Events are delivered in continuous mode as soon as they are available. To reduce the power consumption, applications can use registerListener(android.hardware.SensorEventListener, android.hardware.Sensor, int, int) instead and specify a positive non-zero maximum reporting latency.

registerListener

public boolean registerListener (SensorListener listener, 
                int sensors)

This method was deprecated in API level 15.
This method is deprecated, use SensorManager.registerListener(SensorEventListener, Sensor, int) instead.

Registers a listener for given sensors.

registerListener

public boolean registerListener (SensorListener listener, 
                int sensors, 
                int rate)

This method was deprecated in API level 15.
This method is deprecated, use SensorManager.registerListener(SensorEventListener, Sensor, int) instead.

Registers a SensorListener for given sensors.

registerListener

public boolean registerListener (SensorEventListener listener, 
                Sensor sensor, 
                int samplingPeriodUs, 
                int maxReportLatencyUs, 
                Handler handler)

Registers a SensorEventListener for the given sensor at the given sampling frequency and the given maximum reporting latency.

remapCoordinateSystem

public static boolean remapCoordinateSystem (float[] inR, 
                int X, 
                int Y, 
                float[] outR)

Rotates the supplied rotation matrix so it is expressed in a different coordinate system. This is typically used when an application needs to compute the three orientation angles of the device (see getOrientation(float, float)) in a different coordinate system.

When the rotation matrix is used for drawing (for instance with OpenGL ES), it usually doesn't need to be transformed by this function, unless the screen is physically rotated, in which case you can use Display.getRotation() to retrieve the current rotation of the screen. Note that because the user is generally free to rotate their screen, you often should consider the rotation in deciding the parameters to use here.

Examples:

• Using the camera (Y axis along the camera's axis) for an augmented reality application where the rotation angles are needed:
remapCoordinateSystem(inR, AXIS_X, AXIS_Z, outR);
• Using the device as a mechanical compass when rotation is Surface.ROTATION_90:
remapCoordinateSystem(inR, AXIS_Y, AXIS_MINUS_X, outR);
Beware of the above example. This call is needed only to account for a rotation from its natural orientation when calculating the rotation angles (see getOrientation(float, float)). If the rotation matrix is also used for rendering, it may not need to be transformed, for instance if your Activity is running in landscape mode.

Since the resulting coordinate system is orthonormal, only two axes need to be specified.

requestTriggerSensor

public boolean requestTriggerSensor (TriggerEventListener listener, 
                Sensor sensor)

Requests receiving trigger events for a trigger sensor.

When the sensor detects a trigger event condition, such as significant motion in the case of the Sensor.TYPE_SIGNIFICANT_MOTION, the provided trigger listener will be invoked once and then its request to receive trigger events will be canceled. To continue receiving trigger events, the application must request to receive trigger events again.

unregisterDynamicSensorCallback

public void unregisterDynamicSensorCallback (SensorManager.DynamicSensorCallback callback)

Remove a DynamicSensorCallback to stop sending dynamic sensor connection events to that callback.

unregisterListener

public void unregisterListener (SensorEventListener listener)

Unregisters a listener for all sensors.

unregisterListener

public void unregisterListener (SensorEventListener listener, 
                Sensor sensor)

Unregisters a listener for the sensors with which it is registered.

Note: Don't use this method with a one shot trigger sensor such as Sensor.TYPE_SIGNIFICANT_MOTION. Use cancelTriggerSensor(android.hardware.TriggerEventListener, android.hardware.Sensor) instead.

unregisterListener

public void unregisterListener (SensorListener listener)

This method was deprecated in API level 15.
This method is deprecated, use SensorManager.unregisterListener(SensorEventListener) instead.

Unregisters a listener for all sensors.

unregisterListener

public void unregisterListener (SensorListener listener, 
                int sensors)

This method was deprecated in API level 15.
This method is deprecated, use SensorManager.unregisterListener(SensorEventListener, Sensor) instead.

Unregisters a listener for the sensors with which it is registered.