Android accelerometer class

Question

I tried to create seperate accelerometer class that holds values of accelerometer and I can acces them from any other class whenever I want, but it doesn't seem to work.

Here is my Accelerometer class:

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;

public class Accelero implements SensorEventListener {

    private float xAxis;
    private float yAxis;
    private float zAxis;

    public float getX(){
        return this.xAxis;
    }

    public float getY(){
        return this.yAxis;
    }

    public float getZ(){
        return this.zAxis;
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // TODO Auto-generated method stub

    }

    public void onSensorChanged(SensorEvent event) {
            xAxis = event.values[0];
            yAxis = event.values[1];
            zAxis = event.values[2];
    }

}

so as you see I am trying to get values through get*(); method that I created. But it seems always to return 0, 0, 0 . Any idea what is wrong with my code?

Here is the Activity that this is used in:

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.EditText;

public class MainActivity extends Activity {

    private EditText output;
    private static int DIS = 1;
    Accelero acc;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        output =(EditText) findViewById(R.id.editText1);
        handler.sendEmptyMessageDelayed(DIS, 1);
        acc = new Accelero(this);

    }

    private Handler handler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            if (msg.what == DIS){
                refresh();
                handler.sendEmptyMessageDelayed(DIS, 1);     
            }
        }
    };

    public void refresh(){
        output.setText("X:"+acc.getX()+"\nY:"+acc.getY()+"\nZ:"+acc.getZ());
    }
}

I also have this premission in manifest:

<uses-feature android:name="android.hardware.sensor.accelerometer" android:required="true" />

Can you show the code for the activity which uses this class? — La bla bla, Aug 12 '12 at 12:16

score 1 · Answer 1 · answered Aug 12 '12 at 12:18

You need to register the sensor listener to a sensor manager in your activity

public class Main extends Activity implements SensorEventListener {
    private float mLastX, mLastY, mLastZ;
    private boolean mInitialized;

    private SensorManager mSensorManager;

    private Sensor mAccelerometer;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        mSensorManager.registerListener(new Accelero(), mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
    }
}

See here for a detailed tutorial (code taken from this tutorial)

You need to do this in your Activity's onCreate(). this way you're telling your activity to send the accelerometer's data to this class — La bla bla, Aug 12 '12 at 12:26

score 1 · Accepted Answer · answered Aug 12 '12 at 12:26

1

You have to register the sensor that you are using, in this case the accelerometer. I'm guessing you want everything related to the accelerometer in the "Accelero" class.

To register the listener from that class, you'll have to pass a reference to your activity. So your constructor should look something like this:

SensorManager manager;
Sensor accelerometer;
Activity foo;

public Accelero(Activity foo) {
    this.foo = foo;
    manager = (SensorManager) this.foo.getSystemService(Context.SENSOR_SERVICE);
    accelerometer = manager.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
    manager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_GAME);
 }

and when you create a Accelero object, you simply pass this as the parameter.

I hope this helps.

answered Aug 12 '12 at 12:26

Luke Taylor

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Don't create the Accelero object before you call super.OnCreate(). Is this the problem? – Luke Taylor Aug 12 '12 at 12:38
yes it was i fixed it. but now its till gives me only 0,0,0. It does change after i lock screen and unlock it again – Rohit Malish Aug 12 '12 at 12:39
Please add more code (The code above should read accel data), it might have something to do with your activities code. – Luke Taylor Aug 12 '12 at 12:42
You were right, it was my activity code. now it works. Do you know how can I call that from WallpaperService? – Rohit Malish Aug 12 '12 at 12:46
Good. What do you want to call from a WallpaperService? – Luke Taylor Aug 12 '12 at 13:39
i started a new thread on that question as it is different from this one. http://stackoverflow.com/questions/11922453/calling-accelerometer-from-wallpaperservice – Rohit Malish Aug 12 '12 at 13:42

Android accelerometer class

2 Answers2