MainActivity.java

package com.baruberbagi.compass;

import androidx.appcompat.app.AppCompatActivity;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.service.autofill.FieldClassification;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity implements SensorEventListener {

    private ImageView imageView;
    private float[] gravitasi = new float[3];
    private float[] magnetik = new float[3];
    private float azimut = 0f;
    private float azimutSaatIni = 0f;
    private SensorManager menejerSensor;

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

        imageView = findViewById(R.id.kompass);
        menejerSensor = (SensorManager)getSystemService(SENSOR_SERVICE);

    }

    @Override
    protected void onResume() {
        super.onResume();
        menejerSensor.registerListener(this, menejerSensor.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD),
                SensorManager.SENSOR_DELAY_GAME);
        menejerSensor.registerListener(this, menejerSensor.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
                SensorManager.SENSOR_DELAY_GAME);
    }

    @Override
    protected void onPause() {
        super.onPause();
        menejerSensor.unregisterListener(this);
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        final float alpha = 0.97f;
        synchronized (this){
            if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
                gravitasi[0] = alpha*gravitasi[0]+(1-alpha)*event.values[0];
                gravitasi[1] = alpha*gravitasi[1]+(1-alpha)*event.values[1];
                gravitasi[2] = alpha*gravitasi[2]+(1-alpha)*event.values[2];
            }

            if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD)
            {
                magnetik[0] = alpha*magnetik[0]+(1-alpha)*event.values[0];
                magnetik[1] = alpha*magnetik[1]+(1-alpha)*event.values[1];
                magnetik[2] = alpha*magnetik[2]+(1-alpha)*event.values[2];
            }

            float R[] = new float[9];
            float I[] = new float[9];
            boolean success = SensorManager.getRotationMatrix(R,I,gravitasi,magnetik);
            if (success)
            {
                float orentasi[] = new float[3];
                SensorManager.getOrientation(R,orentasi);
                azimut = (float) Math.toDegrees(orentasi[0]);
                azimut = (azimut + 360)%360;


                Animation animation = new RotateAnimation(-azimutSaatIni,-azimut,Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,0.5f);
                azimutSaatIni = azimut;

                animation.setDuration(500);
                animation.setRepeatCount(0);
                animation.setFillAfter(true);

                imageView.startAnimation(animation);
            }
        }
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
}