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1. Sensors

2. Monitoring the Battery

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1. Sensors

The emulator does not provide any sensor data. All sensor testing must be done on a physical device. Alternatively, OpenIntents.org also provides a handy Sensor Simulator: http://code.google.com/p/openintents/wiki/SensorSimulator This tool simulates accelerometer, compass, and temperature sensors, and it transmits data to the emulator.

Android devices have a variety of sensors :

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1. Sensors

TYPE_ACCELEROMETER: Measures acceleration in three directions; values are in SI units (m/s2).TYPE_GYROSCOPE: Measures angular orientation in three directions; values are angles in degrees.TYPE_LIGHT: Measures ambient light; values are in SI lux units.TYPE_MAGNETIC_FIELD: Measures magnetism in three directions; the compass values are in micro-Tesla (uT).TYPE_PRESSURE: Measures barometric pressure.TYPE_PROXIMITY: Measures the distance to an object; values are in centimeters, or “near” versus “far.”TYPE_RELATIVE_HUMIDITY: Measures the relative humidity.TYPE_AMBIENT_TEMPERATURE: Measures temperature.

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1. SensorsHere are the major classes related to sensor.

Class Comment

Sensor Class representing a sensor. Use getSensorList(int) to get the list of available Sensors.

SensorEvent This class represents a Sensor event and holds informations such as the sensor's type, the time-stamp, accuracy and of course the sensor's data.

SensorEventListener An interface: Used for receiving notifications from the SensorManager when sensor values have changed.

SensorManager SensorManager lets you access the device's sensors. Get an instance of this class by calling Context.getSystemService() with the argument SENSOR_SERVICE.

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1. Sensors Working with Sensor

To get a Sensor, you need to use SensorManager.

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1. Sensors Working with Sensor

Register EventListener to it.

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1. Sensors Working with Sensor

UnRegister EventListener.

Register in the onResume method and Unregister in the onPause method

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1. Sensors

SensorManager.SENSOR_DELAY

Frequence Comment

SENSOR_DELAY_FASTEST get sensor data as fast as possible

SENSOR_DELAY_NORMAL rate (default) suitable for screen orientation changes

SENSOR_DELAY_GAME rate suitable for gamesSENSOR_DELAY_UI rate suitable for the user

interface

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1. Sensors

Receive SensorEvent Normally, onSensorChanged is the method in which we need to put your sensor handle logic.

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1. Sensors SensorEvent

Type Name Commentpublic int accuracy The accuracy of this event.

public Sensor sensor The sensor that generated this event.

public long timestamp The time in nanosecond at which the event happened

public final float[] values The length and contents of the values array depends on which sensor type is being monitored.

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1. Sensors Sensor.TYPE_TEMPERATURE

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1. Sensors Sensor.TYPE_TEMPERATURE

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1. Sensors Sensor.TYPE_LIGHT

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1. Sensors Sensor.TYPE_LIGHT

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1. Sensors Sensor.TYPE_PRESSURE

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1. Sensors Sensor.TYPE_PRESSURE

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1. Sensors Sensor. TYPE_PROXIMITY

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1. Sensors Sensor. TYPE_PROXIMITY

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1. Sensors Sensor. TYPE_PROXIMITY

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1. Sensors Sensor.TYPE_ACCELEROMETER

The accelerometer values are represented in SI units (m/s2). The device at right has the bottom of the device screen pointing toward the center of gravity. Gravity on Earth is 9.80665 m/s2.

All values are in SI units (m/s2)values[0]: Acceleration minus Gx on the x-axisvalues[1]: Acceleration minus Gy on the y-axisvalues[2]: Acceleration minus Gz on the z-axis

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1. Sensors Sensor.TYPE_ACCELEROMETER

Use to Accelerometer to detect SHAKING Device

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1. Sensors Sensor.TYPE_ACCELEROMETER

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1. Sensors Sensor.TYPE_ACCELEROMETER

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1. Sensors Sensor.TYPE_GYROSCOPE

measure, or maintain, the orientation of a device. rate of rotation around a particular axis

values[0]: Angular speed around the x-axisvalues[1]: Angular speed around the y-axisvalues[2]: Angular speed around the z-axis

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1. Sensors Sensor.TYPE_GYROSCOPE

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1. Sensors Sensor.TYPE_GYROSCOPE

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1. Sensors Sensor.TYPE_ORIENTATION

All values are angles in degrees:values[0]: Azimuth, angle between the magnetic north direction and the y-axis, around the z-axis (0 to 359). 0=North, 90=East, 180=South, 270=West

values[1]: Pitch, rotation around x-axis (-180 to 180), with positive values when the z-axis moves toward the y-axis.

values[2]: Roll, rotation around y-axis (-90 to 90), with positive values when the x-axis moves toward the z-axis.

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1. Sensors Sensor.TYPE_ORIENTATION

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1. Sensors

Exercise : Using Sensors Accelerometor and Proximity to build an AlbumManager application:- Nice GUI to display Pictures- When Device was shaken to Left open the Previous Picture- When Device was shaken to Right open the Next Picture- When Proximity is active and event.values[0]==0.0 Close the

AlbumManager application

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2. Monitoring the Battery

A monitoring application can reduce the monitoring frequency when the battery is low and can increase it if the device is powered by an external power source. The battery levels can also help indicate the efficiency of an application, allowing developers to find areas where behavior can be modified to improve battery life, which would be appreciated by users.

To monitor the battery, the application must have the BATTERY_STATS permission:

<uses-permission android:name="android.permission.BATTERY_STATS"/>

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2. Monitoring the Battery

Then the application needs to register for a particular BroadcastIntent. In this case, it must be Intent.ACTION_BATTERY_CHANGED.

Emulator Physical Device

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2. Monitoring the Battery

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