Mega Code Archive
Speed sensor
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package app.test;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.content.Context;
import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.os.Handler;
import android.widget.TextView;
public class Test extends Activity {
Handler handler = new Handler();
SensorManager sensorManager;
TextView myTextView;
float appliedAcceleration = 0;
float currentAcceleration = 0;
float velocity = 0;
Date lastUpdate;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
myTextView = (TextView) findViewById(R.id.myTextView);
lastUpdate = new Date(System.currentTimeMillis());
sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
sensorManager.registerListener(sensorListener,
SensorManager.SENSOR_ACCELEROMETER,
SensorManager.SENSOR_DELAY_FASTEST);
Timer updateTimer = new Timer("velocityUpdate");
updateTimer.scheduleAtFixedRate(new TimerTask() {
public void run() {
updateGUI();
}
}, 0, 1000);
}
private void updateGUI() {
handler.post(new Runnable() {
public void run() {
myTextView.setText(velocity + "");
}
});
}
private void updateVelocity() {
Date timeNow = new Date(System.currentTimeMillis());
long timeDelta = timeNow.getTime() - lastUpdate.getTime();
lastUpdate.setTime(timeNow.getTime());
float deltaVelocity = appliedAcceleration * (timeDelta / 1000);
appliedAcceleration = currentAcceleration;
velocity += deltaVelocity;
}
private final SensorListener sensorListener = new SensorListener() {
double calibration = Double.NaN;
public void onSensorChanged(int sensor, float[] values) {
double x = values[SensorManager.DATA_X];
double y = values[SensorManager.DATA_Y];
double z = values[SensorManager.DATA_Z];
double a = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2)
+ Math.pow(z, 2));
if (calibration == Double.NaN)
calibration = a;
else {
updateVelocity();
currentAcceleration = (float) a;
}
}
public void onAccuracyChanged(int sensor, int accuracy) {
}
};
}
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