Android Application Development

Sensor Programming

Ahsanul Karim ahsanul.karim@sentinelbd.com

Sentinel Solutions Ltd.http://www.sentinelbd.com

Sensor ProgrammingAndroid Sensors1. Android phones support different sensors. 2. Today we write test code that reports which sensors our Android device

supports. 3. Unfortunately, the emulator supports none upto SDK 1.5.4. But we’ll see how many sensors are supported

in real device5. We’ll create a project named SensorTest for this.

We’ll test following sensor list:

1. Accelerometer2. Light3. Magnetic Field4. Orientation5. Orientation Raw6. Proximity7. Temperature8. Tricorder

This is for SDK 1.5

Sensor ProgrammingAndroid Sensors TestWe create a project named

SensorTest

Sensor ProgrammingAndroid Sensors Test1. We change our Activity to a

ListActivity

Sensor ProgrammingAndroid Sensors Test2. We’ll use SensorManager class

3. So we declare a List for SensorInfo 4. SensorInfo is a class defined by us which holds the sensor name and a boolean value whether its supported or not.5. So we create a SensorInfo class

Sensor ProgrammingAndroid Sensors Test6. Let’s get back to our

ListActivity

7. We’ll now populate the list with all sensors and check whether they are enabled

Sensor ProgrammingAndroid Sensors Test

8. We declare a List of SensorInfo

9. Now we check each sensor one by one: First Accelerometer

10. Now we check each sensor one by one: then Light

Sensor ProgrammingAndroid Sensors Test11. Now we check each sensor one by

one: First Magnetic field

12. Now we check each sensor one by one: then Orientation

Sensor ProgrammingAndroid Sensors Test13. Now we check each sensor one by

one: First Orientation Raw

14. Now we check each sensor one by one: then Proximity

Sensor ProgrammingAndroid Sensors Test15. Now we check each sensor one by

one: First Temperature

16. Now we check each sensor one by one: then Tricorder

Sensor ProgrammingAndroid Sensors Test17. To show the list we do the following by setting

adapter

Now we run the app in emulator.

Except Accelerometer we see all sensors are disabledMay be in later SDKs we’ll get more enabled sensors

Sensor ProgrammingAndroid Sensors TestLets run this in Galaxy

tab We see the following are enabled:

1. Accelerometer2. Light3. Magnetic Field4. Orientation5. Orientation Raw6. Proximity

So the sensor support varies from Vendor to vendor and model to model

Sensor ProgrammingAndroid Sensor Programming

As we see that Accelerometer is the 1. most commonly used sensor and also 2. it has many applications in games development, We’ll see and example of Sensor programming with

Accelerometer

And as we don’t have option to move the emulator we may have to use a

sensor simulator which will simulate the sensor data.So we download the library for sensorsimulation at:http://openintents.googlecode.com/files/sensorsimulator-1.1.0-rc1.ziphttp://code.google.com/p/openintents/downloads/detail?name=sensorsimulator-1.1.0-rc1.

zip&can=2&q=http://code.google.com/p/openintents/wiki/SensorSimulator

We can follow their instruction to use it.

But here, we’ll do it in our real device, so simulator will not be required

Sensor ProgrammingAndroid Sensor ProgrammingLet’s create a project as an

exampleWe create a layout with a simple image which will move according to the Accelerometer:

Sensor ProgrammingAndroid Sensor Programming

Our Activity:

Sensor ProgrammingAndroid Sensor Programming

Adding SensorEventListener inner class with data update

Sensor ProgrammingAndroid Sensor ProgrammingDeclaring variables and registering

listener

Sensor ProgrammingAndroid Sensor Programming

Register and unregister listener on activity onStop and onResume: