Monday, February 21, 2011

Detect Shaking

By comparing previous and current reading of build-in accelerometer sensor, shaking of android device can be detected.

Detect Shaking

In this exercise, three SeekBar is used to adjust the sensitive of x, y, z. The changing rate are compare with the sensitive to detect shaking.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<SeekBar
android:id="@+id/xsensitive"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="100"
/>
<TextView
android:id="@+id/x"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/xrate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/xstate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<SeekBar
android:id="@+id/ysensitive"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="100"
/>
<TextView
android:id="@+id/y"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/yrate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/ystate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<SeekBar
android:id="@+id/zsensitive"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="100"
/>
<TextView
android:id="@+id/z"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/zrate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/zstate"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>


package com.exercise.AndroidDetectShaking;

import java.util.List;

import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.TextView;

public class AndroidDetectShaking extends Activity {

TextView text_x, text_xrate, text_xstate;
TextView text_y, text_yrate, text_ystate;
TextView text_z, text_zrate, text_zstate;
SeekBar seekbar_x, seekbar_y, seekbar_z;

SensorManager sensorManager;
Sensor accelerometerSensor;
boolean accelerometerPresent;

float SensitiveX, SensitiveY, SensitiveZ;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

seekbar_x = (SeekBar)findViewById(R.id.xsensitive);
text_x = (TextView)findViewById(R.id.x);
text_xrate = (TextView)findViewById(R.id.xrate);
text_xstate = (TextView)findViewById(R.id.xstate);
seekbar_y = (SeekBar)findViewById(R.id.ysensitive);
text_y = (TextView)findViewById(R.id.y);
text_yrate = (TextView)findViewById(R.id.yrate);
text_ystate = (TextView)findViewById(R.id.ystate);
seekbar_z = (SeekBar)findViewById(R.id.zsensitive);
text_z = (TextView)findViewById(R.id.z);
text_zrate = (TextView)findViewById(R.id.zrate);
text_zstate = (TextView)findViewById(R.id.zstate);

seekbar_x.setOnSeekBarChangeListener(seekbar_sensitiveOnSeekBarChangeListener);
seekbar_y.setOnSeekBarChangeListener(seekbar_sensitiveOnSeekBarChangeListener);
seekbar_z.setOnSeekBarChangeListener(seekbar_sensitiveOnSeekBarChangeListener);

sensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
List<Sensor> sensorList = sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER);
if(sensorList.size() > 0){
accelerometerPresent = true;
accelerometerSensor = sensorList.get(0);
}
else{
accelerometerPresent = false;
}
}

SeekBar.OnSeekBarChangeListener seekbar_sensitiveOnSeekBarChangeListener
= new SeekBar.OnSeekBarChangeListener(){

@Override
public void onProgressChanged(SeekBar arg0, int arg1, boolean arg2) {
// TODO Auto-generated method stub
if (arg0 == seekbar_x){
SensitiveX = (float)arg1;
}else if (arg0 == seekbar_y){
SensitiveY = (float)arg1;
}else if (arg0 == seekbar_z){
SensitiveZ = (float)arg1;
}
}

@Override
public void onStartTrackingTouch(SeekBar arg0) {
// TODO Auto-generated method stub
}

@Override
public void onStopTrackingTouch(SeekBar arg0) {
// TODO Auto-generated method stub
}};

@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
if(accelerometerPresent){
sensorManager.registerListener(accelerometerListener, accelerometerSensor, SensorManager.SENSOR_DELAY_NORMAL);
}
}

@Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
if(accelerometerPresent){
sensorManager.unregisterListener(accelerometerListener);
}
}

private SensorEventListener accelerometerListener = new SensorEventListener(){

float lastx, lasty, lastz;
long lasttime;
boolean firsttime = true;

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

@Override
public void onSensorChanged(SensorEvent arg0) {
// TODO Auto-generated method stub
float x_value = arg0.values[0];
float y_value = arg0.values[1];
float z_value = arg0.values[2];
text_x.setText(String.valueOf(x_value));
text_y.setText(String.valueOf(y_value));
text_z.setText(String.valueOf(z_value));

long currenttime = System.currentTimeMillis();
if(!firsttime){
long deltatime = currenttime - lasttime;
float xrate = Math.abs(x_value - lastx) * 10000/deltatime;
float yrate = Math.abs(y_value - lasty) * 10000/deltatime;
float zrate = Math.abs(z_value - lastz) * 10000/deltatime;
text_xrate.setText(String.valueOf(xrate));
text_yrate.setText(String.valueOf(yrate));
text_zrate.setText(String.valueOf(zrate));

if (xrate>SensitiveX){
text_xstate.setText("Shaking:)");
}else{
text_xstate.setText("");
}

if (yrate>SensitiveY){
text_ystate.setText("Shaking:)");
}else{
text_ystate.setText("");
}

if (zrate>SensitiveZ){
text_zstate.setText("Shaking:)");
}else{
text_zstate.setText("");
}
}
lasttime = currenttime;
lastx = x_value;
lasty = y_value;
lastz = z_value;
firsttime = false;
}
};
}


Download the files.

4 comments:

bdmapper said...

Hi ,
Are you from bangladesh ? anyway your blog is very helpfull for me .

Thanks,
Shafiul hasan

Android Er said...

hello bdmapper,

No, I'm not from bangladesh:)

Abhishek Deswal said...

hey ,
Can i run this code in android studio?

Andr.oid Eric said...

hello Abhishek Deswal,

Suppose it can.