Getting 0 as return values from accelrometer

Question

I am having problem with this accelerometer coding. I keep getting 0 as my return value from the accelerometer. Just ignore the cal_displace part first because now i cant get any value form the accelerometer. your help is much appreciated.

package com.example.suntracking;

import android.app.Activity;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;

public class Accelerometer extends Activity implements SensorEventListener{
Sensor accelerometer;
SensorManager sm;
int samintval;
float ax,ay,axtemp ,aytemp ,sx,sy;
TextView showax,showay,showaxtemp,showaytemp;
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.accelerometer);
    loadsavedPref();
    initialize();
    cal_displace();
    display();
    savePreferences();
}


private void display() {
    // TODO Auto-generated method stub
    showax.setText(""+ax);
    showay.setText(""+ay);
    showaxtemp.setText(""+axtemp);
    showaytemp.setText(""+aytemp);
}


@Override
protected void onResume()
{
super.onResume();
sm.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}
@Override
protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    sm.unregisterListener(this);
}


private void initialize() {
    // TODO Auto-generated method stub
    showax=(TextView)findViewById(R.id.tvax);
    showay=(TextView)findViewById(R.id.tvay);
    showaxtemp=(TextView)findViewById(R.id.tvaxtemp);
    showaytemp=(TextView)findViewById(R.id.tvaytemp);
    sm=(SensorManager)getSystemService(SENSOR_SERVICE);
    accelerometer=sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
    sm.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}

private void loadsavedPref() {
    // TODO Auto-generated method stub
    SharedPreferences savedata= getSharedPreferences("savealldata",0);
    samintval = savedata.getInt("samintval", 1000);
}

private void cal_displace() {
    // TODO Auto-generated method stub
    sx = (float) (0.5 * ((ax - axtemp)/(samintval/1000)) * (samintval / 1000)*(samintval / 1000));
    sy = (float) (0.5 * ((ay - aytemp)/(samintval/1000)) * (samintval / 1000)*(samintval / 1000));
    //axtemp = ax;
    //aytemp = ay;
}

@Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
    // TODO Auto-generated method stub

}
@Override
public void onSensorChanged(SensorEvent event) {
    // TODO Auto-generated method stub
    if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
        return;
    ax = event.values[0];
    ay = event.values[1];
     }

private void savePreferences() {
    // TODO Auto-generated method stub
    SharedPreferences savedata = getSharedPreferences("savealldata",0);
    Editor editor=savedata.edit();
    editor.putFloat("ax", ax);
    editor.putFloat("ay", ay);
    editor.putFloat("axtemp", axtemp);
    editor.putFloat("aytemp", aytemp);
    editor.commit();
}

}

Answer 1

1. You're registering sensor listener twice, in initialize() and in onResume() - do it in onResume() only.

2. You're getting the values, but not updating your TextViews. Modify your onSensorChanged():

   @Override
   public void onSensorChanged(SensorEvent event) {
       if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
           return;
   
       ax = event.values[0];
       ay = event.values[1];
   
       //update TextViews
       display();    
   }