android.hardware.Sensor Maven / Gradle / Ivy
Show all versions of android-all Show documentation
/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.hardware;
import android.os.Build;
/**
* Class representing a sensor. Use {@link SensorManager#getSensorList} to get
* the list of available Sensors.
*
* @see SensorManager
* @see SensorEventListener
* @see SensorEvent
*
*/
public final class Sensor {
/**
* A constant describing an accelerometer sensor type.
* See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_ACCELEROMETER = 1;
/**
* A constant describing a magnetic field sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_MAGNETIC_FIELD = 2;
/**
* A constant describing an orientation sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*
* @deprecated use {@link android.hardware.SensorManager#getOrientation
* SensorManager.getOrientation()} instead.
*/
@Deprecated
public static final int TYPE_ORIENTATION = 3;
/** A constant describing a gyroscope sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details. */
public static final int TYPE_GYROSCOPE = 4;
/**
* A constant describing a light sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_LIGHT = 5;
/** A constant describing a pressure sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details. */
public static final int TYPE_PRESSURE = 6;
/**
* A constant describing a temperature sensor type
*
* @deprecated use
* {@link android.hardware.Sensor#TYPE_AMBIENT_TEMPERATURE
* Sensor.TYPE_AMBIENT_TEMPERATURE} instead.
*/
@Deprecated
public static final int TYPE_TEMPERATURE = 7;
/**
* A constant describing a proximity sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_PROXIMITY = 8;
/**
* A constant describing a gravity sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_GRAVITY = 9;
/**
* A constant describing a linear acceleration sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_LINEAR_ACCELERATION = 10;
/**
* A constant describing a rotation vector sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_ROTATION_VECTOR = 11;
/**
* A constant describing a relative humidity sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details.
*/
public static final int TYPE_RELATIVE_HUMIDITY = 12;
/** A constant describing an ambient temperature sensor type.
*
See {@link android.hardware.SensorEvent#values SensorEvent.values}
* for more details. */
public static final int TYPE_AMBIENT_TEMPERATURE = 13;
/**
* 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 int TYPE_MAGNETIC_FIELD_UNCALIBRATED = 14;
/**
* 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 int TYPE_GAME_ROTATION_VECTOR = 15;
/**
* 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 int TYPE_GYROSCOPE_UNCALIBRATED = 16;
/**
* 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.
*
See {@link TriggerEvent} for more details.
*/
public static final int TYPE_SIGNIFICANT_MOTION = 17;
/**
* 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.
*
* See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.
*/
public static final int TYPE_STEP_DETECTOR = 18;
/**
* 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 first step for that event was taken. This sensor is implemented in hardware and is
* expected to be low power.
*
* See {@link android.hardware.SensorEvent#values SensorEvent.values} for more details.
*/
public static final int TYPE_STEP_COUNTER = 19;
/**
* A constant describing the 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 int TYPE_GEOMAGNETIC_ROTATION_VECTOR = 20;
/**
* A constant describing all sensor types.
*/
public static final int TYPE_ALL = -1;
/* Reporting mode constants for sensors. Each sensor will have exactly one
reporting mode associated with it. */
// Events are reported at a constant rate.
static int REPORTING_MODE_CONTINUOUS = 1;
// Events are reported only when the value changes.
static int REPORTING_MODE_ON_CHANGE = 2;
// Upon detection of an event, the sensor deactivates itself and then sends a single event.
static int REPORTING_MODE_ONE_SHOT = 3;
// TODO(): The following arrays are fragile and error-prone. This needs to be refactored.
// Note: This needs to be updated, whenever a new sensor is added.
// Holds the reporting mode and maximum length of the values array
// associated with
// {@link SensorEvent} or {@link TriggerEvent} for the Sensor
private static final int[] sSensorReportingModes = {
0, 0, // padding because sensor types start at 1
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_ACCELEROMETER
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_GEOMAGNETIC_FIELD
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_ORIENTATION
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_GYROSCOPE
REPORTING_MODE_ON_CHANGE, 3, // SENSOR_TYPE_LIGHT
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_PRESSURE
REPORTING_MODE_ON_CHANGE, 3, // SENSOR_TYPE_TEMPERATURE
REPORTING_MODE_ON_CHANGE, 3, // SENSOR_TYPE_PROXIMITY
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_GRAVITY
REPORTING_MODE_CONTINUOUS, 3, // SENSOR_TYPE_LINEAR_ACCELERATION
REPORTING_MODE_CONTINUOUS, 5, // SENSOR_TYPE_ROTATION_VECTOR
REPORTING_MODE_ON_CHANGE, 3, // SENSOR_TYPE_RELATIVE_HUMIDITY
REPORTING_MODE_ON_CHANGE, 3, // SENSOR_TYPE_AMBIENT_TEMPERATURE
REPORTING_MODE_CONTINUOUS, 6, // SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED
REPORTING_MODE_CONTINUOUS, 4, // SENSOR_TYPE_GAME_ROTATION_VECTOR
REPORTING_MODE_CONTINUOUS, 6, // SENSOR_TYPE_GYROSCOPE_UNCALIBRATED
REPORTING_MODE_ONE_SHOT, 1, // SENSOR_TYPE_SIGNIFICANT_MOTION
// added post 4.3
REPORTING_MODE_ON_CHANGE, 1, // SENSOR_TYPE_STEP_DETECTOR
REPORTING_MODE_ON_CHANGE, 1, // SENSOR_TYPE_STEP_COUNTER
REPORTING_MODE_CONTINUOUS, 5 // SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR
};
static int getReportingMode(Sensor sensor) {
int offset = sensor.mType * 2;
if (offset >= sSensorReportingModes.length) {
// we don't know about this sensor, so this is probably a
// vendor-defined sensor, in that case, we figure out the reporting
// mode from the sensor meta-data.
int minDelay = sensor.mMinDelay;
if (minDelay == 0) {
return REPORTING_MODE_ON_CHANGE;
} else if (minDelay < 0) {
return REPORTING_MODE_ONE_SHOT;
} else {
return REPORTING_MODE_CONTINUOUS;
}
}
return sSensorReportingModes[offset];
}
static int getMaxLengthValuesArray(Sensor sensor, int sdkLevel) {
int type = sensor.mType;
// RotationVector length has changed to 3 to 5 for API level 18
// Set it to 3 for backward compatibility.
if (type == Sensor.TYPE_ROTATION_VECTOR &&
sdkLevel <= Build.VERSION_CODES.JELLY_BEAN_MR1) {
return 3;
}
int offset = type * 2 + 1;
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];
}
/* Some of these fields are set only by the native bindings in
* SensorManager.
*/
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;
Sensor() {
}
/**
* @return name string of the sensor.
*/
public String getName() {
return mName;
}
/**
* @return vendor string of this sensor.
*/
public String getVendor() {
return mVendor;
}
/**
* @return generic type of this sensor.
*/
public int getType() {
return mType;
}
/**
* @return version of the sensor's module.
*/
public int getVersion() {
return mVersion;
}
/**
* @return maximum range of the sensor in the sensor's unit.
*/
public float getMaximumRange() {
return mMaxRange;
}
/**
* @return resolution of the sensor in the sensor's unit.
*/
public float getResolution() {
return mResolution;
}
/**
* @return the power in mA used by this sensor while in use
*/
public float getPower() {
return mPower;
}
/**
* @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.
*/
public int getMinDelay() {
return mMinDelay;
}
/**
* @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.
*/
public int getFifoReservedEventCount() {
return mFifoReservedEventCount;
}
/**
* @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.
*/
public int getFifoMaxEventCount() {
return mFifoMaxEventCount;
}
/** @hide */
public int getHandle() {
return mHandle;
}
void setRange(float max, float res) {
mMaxRange = max;
mResolution = res;
}
@Override
public String toString() {
return "{Sensor name=\"" + mName + "\", vendor=\"" + mVendor + "\", version=" + mVersion
+ ", type=" + mType + ", maxRange=" + mMaxRange + ", resolution=" + mResolution
+ ", power=" + mPower + ", minDelay=" + mMinDelay + "}";
}
}