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Sensor.javaAPI DocAndroid 5.1 API31594Thu Mar 12 22:22:10 GMT 2015android.hardware

Sensor

public final class Sensor extends Object
Class representing a sensor. Use {@link SensorManager#getSensorList} to get the list of available Sensors.
see
SensorManager
see
SensorEventListener
see
SensorEvent

Fields Summary
public static final int
TYPE_ACCELEROMETER
A constant describing an accelerometer sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_ACCELEROMETER
A constant string describing an accelerometer sensor type.
public static final int
TYPE_MAGNETIC_FIELD
A constant describing a magnetic field sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_MAGNETIC_FIELD
A constant string describing a magnetic field sensor type.
public static final int
TYPE_ORIENTATION
A constant describing an orientation sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_ORIENTATION
A constant string describing an orientation sensor type.
public static final int
TYPE_GYROSCOPE
A constant describing a gyroscope sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_GYROSCOPE
A constant string describing a gyroscope sensor type.
public static final int
TYPE_LIGHT
A constant describing a light sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_LIGHT
A constant string describing a light sensor type.
public static final int
TYPE_PRESSURE
A constant describing a pressure sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_PRESSURE
A constant string describing a pressure sensor type.
public static final int
TYPE_TEMPERATURE
A constant describing a temperature sensor type
public static final String
STRING_TYPE_TEMPERATURE
A constant string describing a temperature sensor type
public static final int
TYPE_PROXIMITY
A constant describing a proximity sensor type. This is a wake up sensor.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_PROXIMITY
A constant string describing a proximity sensor type.
public static final int
TYPE_GRAVITY
A constant describing a gravity sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_GRAVITY
A constant string describing a gravity sensor type.
public static final int
TYPE_LINEAR_ACCELERATION
A constant describing a linear acceleration sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_LINEAR_ACCELERATION
A constant string describing a linear acceleration sensor type.
public static final int
TYPE_ROTATION_VECTOR
A constant describing a rotation vector sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_ROTATION_VECTOR
A constant string describing a rotation vector sensor type.
public static final int
TYPE_RELATIVE_HUMIDITY
A constant describing a relative humidity sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_RELATIVE_HUMIDITY
A constant string describing a relative humidity sensor type
public static final int
TYPE_AMBIENT_TEMPERATURE
A constant describing an ambient temperature sensor type.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_AMBIENT_TEMPERATURE
A constant string describing an ambient temperature sensor type.
public static final int
TYPE_MAGNETIC_FIELD_UNCALIBRATED
A constant describing an uncalibrated magnetic field sensor type.

Similar to {@link #TYPE_MAGNETIC_FIELD} but the hard iron calibration (device calibration due to distortions that arise from magnetized iron, steel or permanent magnets on the device) is not considered in the given sensor values. However, such hard iron bias values are returned to you separately in the result {@link android.hardware.SensorEvent#values} so you may use them for custom calibrations.

Also, no periodic calibration is performed (i.e. there are no discontinuities in the data stream while using this sensor) and assumptions that the magnetic field is due to the Earth's poles is avoided, but factory calibration and temperature compensation have been performed.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_MAGNETIC_FIELD_UNCALIBRATED
A constant string describing an uncalibrated magnetic field sensor type.
public static final int
TYPE_GAME_ROTATION_VECTOR
A constant describing an uncalibrated rotation vector sensor type.

Identical to {@link #TYPE_ROTATION_VECTOR} except that it doesn't use the geomagnetic field. Therefore the Y axis doesn't point north, but instead to some other reference, that reference is allowed to drift by the same order of magnitude as the gyroscope drift around the Z axis.

In the ideal case, a phone rotated and returning to the same real-world orientation should report the same game rotation vector (without using the earth's geomagnetic field). However, the orientation may drift somewhat over time.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_GAME_ROTATION_VECTOR
A constant string describing an uncalibrated rotation vector sensor type.
public static final int
TYPE_GYROSCOPE_UNCALIBRATED
A constant describing an uncalibrated gyroscope sensor type.

Similar to {@link #TYPE_GYROSCOPE} but no gyro-drift compensation has been performed to adjust the given sensor values. However, such gyro-drift bias values are returned to you separately in the result {@link android.hardware.SensorEvent#values} so you may use them for custom calibrations.

Factory calibration and temperature compensation is still applied to the rate of rotation (angular speeds).

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_GYROSCOPE_UNCALIBRATED
A constant string describing an uncalibrated gyroscope sensor type.
public static final int
TYPE_SIGNIFICANT_MOTION
A constant describing a significant motion trigger sensor.

It triggers when an event occurs and then automatically disables itself. The sensor continues to operate while the device is asleep and will automatically wake the device to notify when significant motion is detected. The application does not need to hold any wake locks for this sensor to trigger. This is a wake up sensor.

See {@link TriggerEvent} for more details.

public static final String
STRING_TYPE_SIGNIFICANT_MOTION
A constant string describing a significant motion trigger sensor.
public static final int
TYPE_STEP_DETECTOR
A constant describing a step detector sensor.

A sensor of this type triggers an event each time a step is taken by the user. The only allowed value to return is 1.0 and an event is generated for each step. Like with any other event, the timestamp indicates when the event (here the step) occurred, this corresponds to when the foot hit the ground, generating a high variation in acceleration. This sensor is only for detecting every individual step as soon as it is taken, for example to perform dead reckoning. If you only need aggregate number of steps taken over a period of time, register for {@link #TYPE_STEP_COUNTER} instead. It is defined as a {@link Sensor#REPORTING_MODE_SPECIAL_TRIGGER} sensor.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_STEP_DETECTOR
A constant string describing a step detector sensor.
public static final int
TYPE_STEP_COUNTER
A constant describing a step counter sensor.

A sensor of this type returns the number of steps taken by the user since the last reboot while activated. The value is returned as a float (with the fractional part set to zero) and is reset to zero only on a system reboot. The timestamp of the event is set to the time when the last step for that event was taken. This sensor is implemented in hardware and is expected to be low power. If you want to continuously track the number of steps over a long period of time, do NOT unregister for this sensor, so that it keeps counting steps in the background even when the AP is in suspend mode and report the aggregate count when the AP is awake. Application needs to stay registered for this sensor because step counter does not count steps if it is not activated. This sensor is ideal for fitness tracking applications. It is defined as an {@link Sensor#REPORTING_MODE_ON_CHANGE} sensor.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_STEP_COUNTER
A constant string describing a step counter sensor.
public static final int
TYPE_GEOMAGNETIC_ROTATION_VECTOR
A constant describing a geo-magnetic rotation vector.

Similar to {@link #TYPE_ROTATION_VECTOR}, but using a magnetometer instead of using a gyroscope. This sensor uses lower power than the other rotation vectors, because it doesn't use the gyroscope. However, it is more noisy and will work best outdoors.

See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.

public static final String
STRING_TYPE_GEOMAGNETIC_ROTATION_VECTOR
A constant string describing a geo-magnetic rotation vector.
public static final int
TYPE_HEART_RATE
A constant describing a heart rate monitor.

The reported value is the heart rate in beats per minute.

The reported accuracy represents the status of the monitor during the reading. See the {@code SENSOR_STATUS_*} constants in {@link android.hardware.SensorManager SensorManager} for more details on accuracy/status values. In particular, when the accuracy is {@code SENSOR_STATUS_UNRELIABLE} or {@code SENSOR_STATUS_NO_CONTACT}, the heart rate value should be discarded.

This sensor requires permission {@code android.permission.BODY_SENSORS}. It will not be returned by {@code SensorManager.getSensorsList} nor {@code SensorManager.getDefaultSensor} if the application doesn't have this permission.

public static final String
STRING_TYPE_HEART_RATE
A constant string describing a heart rate monitor.
public static final int
TYPE_TILT_DETECTOR
A sensor of this type generates an event each time a tilt event is detected. A tilt event is generated if the direction of the 2-seconds window average gravity changed by at least 35 degrees since the activation of the sensor. It is a wake up sensor.
public static final String
SENSOR_STRING_TYPE_TILT_DETECTOR
A constant string describing a wake up tilt detector sensor type.
public static final int
TYPE_WAKE_GESTURE
A constant describing a wake gesture sensor.

Wake gesture sensors enable waking up the device based on a device specific motion.

When this sensor triggers, the device behaves as if the power button was pressed, turning the screen on. This behavior (turning on the screen when this sensor triggers) might be deactivated by the user in the device settings. Changes in settings do not impact the behavior of the sensor: only whether the framework turns the screen on when it triggers.

The actual gesture to be detected is not specified, and can be chosen by the manufacturer of the device. This sensor must be low power, as it is likely to be activated 24/7. Values of events created by this sensors should not be used.

public static final String
STRING_TYPE_WAKE_GESTURE
A constant string describing a wake gesture sensor.
public static final int
TYPE_GLANCE_GESTURE
A constant describing a wake gesture sensor.

A sensor enabling briefly turning the screen on to enable the user to glance content on screen based on a specific motion. The device should turn the screen off after a few moments.

When this sensor triggers, the device turns the screen on momentarily to allow the user to glance notifications or other content while the device remains locked in a non-interactive state (dozing). This behavior (briefly turning on the screen when this sensor triggers) might be deactivated by the user in the device settings. Changes in settings do not impact the behavior of the sensor: only whether the framework briefly turns the screen on when it triggers.

The actual gesture to be detected is not specified, and can be chosen by the manufacturer of the device. This sensor must be low power, as it is likely to be activated 24/7. Values of events created by this sensors should not be used.

public static final String
STRING_TYPE_GLANCE_GESTURE
A constant string describing a wake gesture sensor.
public static final int
TYPE_PICK_UP_GESTURE
A constant describing a pick up sensor. A sensor of this type triggers when the device is picked up regardless of wherever it was before (desk, pocket, bag). The only allowed return value is 1.0. This sensor deactivates itself immediately after it triggers.
public static final String
STRING_TYPE_PICK_UP_GESTURE
A constant string describing a pick up sensor.
public static final int
TYPE_ALL
A constant describing all sensor types.
private static final int
SENSOR_FLAG_WAKE_UP_SENSOR
public static final int
REPORTING_MODE_CONTINUOUS
Events are reported at a constant rate which is set by the rate parameter of {@link SensorManager#registerListener(SensorEventListener, Sensor, int)}. Note: If other applications are requesting a higher rate, the sensor data might be delivered at faster rates than requested.
public static final int
REPORTING_MODE_ON_CHANGE
Events are reported only when the value changes. Event delivery rate can be limited by setting appropriate value for rate parameter of {@link SensorManager#registerListener(SensorEventListener, Sensor, int)} Note: If other applications are requesting a higher rate, the sensor data might be delivered at faster rates than requested.
public static final int
REPORTING_MODE_ONE_SHOT
Events are reported in one-shot mode. Upon detection of an event, the sensor deactivates itself and then sends a single event. Sensors of this reporting mode must be registered to using {@link SensorManager#requestTriggerSensor(TriggerEventListener, Sensor)}.
public static final int
REPORTING_MODE_SPECIAL_TRIGGER
Events are reported as described in the description of the sensor. The rate passed to registerListener might not have an impact on the rate of event delivery. See the sensor definition for more information on when and how frequently the events are reported. For example, step detectors report events when a step is detected.
private static final int
REPORTING_MODE_MASK
private static final int
REPORTING_MODE_SHIFT
private static final int[]
sSensorReportingModes
private String
mName
private String
mVendor
private int
mVersion
private int
mHandle
private int
mType
private float
mMaxRange
private float
mResolution
private float
mPower
private int
mMinDelay
private int
mFifoReservedEventCount
private int
mFifoMaxEventCount
private String
mStringType
private String
mRequiredPermission
private int
mMaxDelay
private int
mFlags
Constructors Summary
Sensor()
Methods Summary
public intgetFifoMaxEventCount()

return
Maximum number of events of this sensor that could be batched. If this value is zero it indicates that batch mode is not supported for this sensor. If other applications registered to batched sensors, the actual number of events that can be batched might be smaller because the hardware FiFo will be partially used to batch the other sensors.

        return mFifoMaxEventCount;
public intgetFifoReservedEventCount()

return
Number of events reserved for this sensor in the batch mode FIFO. This gives a guarantee on the minimum number of events that can be batched.

        return mFifoReservedEventCount;
public intgetHandle()

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        return mHandle;
public intgetMaxDelay()
This value is defined only for continuous and on-change sensors. It is the delay between two sensor events corresponding to the lowest frequency that this sensor supports. When lower frequencies are requested through registerListener() the events will be generated at this frequency instead. It can be used to estimate when the batch FIFO may be full. Older devices may set this value to zero. Ignore this value in case it is negative or zero.

return
The max delay for this sensor in microseconds.

        return mMaxDelay;
static intgetMaxLengthValuesArray(android.hardware.Sensor sensor, int sdkLevel)

        // RotationVector length has changed to 3 to 5 for API level 18
        // Set it to 3 for backward compatibility.
        if (sensor.mType == Sensor.TYPE_ROTATION_VECTOR &&
                sdkLevel <= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            return 3;
        }
        int offset = sensor.mType;
        if (offset >= sSensorReportingModes.length) {
            // we don't know about this sensor, so this is probably a
            // vendor-defined sensor, in that case, we don't know how many value
            // it has
            // so we return the maximum and assume the app will know.
            // FIXME: sensor HAL should advertise how much data is returned per
            // sensor
            return 16;
        }
        return sSensorReportingModes[offset];
public floatgetMaximumRange()

return
maximum range of the sensor in the sensor's unit.

        return mMaxRange;
public intgetMinDelay()

return
the minimum delay allowed between two events in microsecond or zero if this sensor only returns a value when the data it's measuring changes.

        return mMinDelay;
public java.lang.StringgetName()

return
name string of the sensor.

        return mName;
public floatgetPower()

return
the power in mA used by this sensor while in use

        return mPower;
public intgetReportingMode()
Each sensor has exactly one reporting mode associated with it. This method returns the reporting mode constant for this sensor type.

return
Reporting mode for the input sensor, one of REPORTING_MODE_* constants.
see
#REPORTING_MODE_CONTINUOUS
see
#REPORTING_MODE_ON_CHANGE
see
#REPORTING_MODE_ONE_SHOT
see
#REPORTING_MODE_SPECIAL_TRIGGER


                                                 
       
        return ((mFlags & REPORTING_MODE_MASK) >> REPORTING_MODE_SHIFT);
public java.lang.StringgetRequiredPermission()

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return
The permission required to access this sensor. If empty, no permission is required.

        return mRequiredPermission;
public floatgetResolution()

return
resolution of the sensor in the sensor's unit.

        return mResolution;
public java.lang.StringgetStringType()

return
The type of this sensor as a string.

        return mStringType;
public intgetType()

return
generic type of this sensor.

        return mType;
public java.lang.StringgetVendor()

return
vendor string of this sensor.

        return mVendor;
public intgetVersion()

return
version of the sensor's module.

        return mVersion;
public booleanisWakeUpSensor()
Returns true if the sensor is a wake-up sensor.

Application Processor Power modes

Application Processor(AP), is the processor on which applications run. When no wake lock is held and the user is not interacting with the device, this processor can enter a â