FFTDrawer/app/src/main/java/com/feemers/android/fftdrawer/SignalProcessing/MySensor.java

package com.feemers.android.fftdrawer.SignalProcessing;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.util.Log;

public class  MySensor extends SensorImpl implements SensorEventListener {
    private SensorManager sensorManager;
    private Sensor m_sensor;
    private int sensorType = Sensor.TYPE_ACCELEROMETER;
    private long time_former_value;
    private long time_current_value;

    private int sample_cnt;

    public MySensor()
    {
        m_sensor = null;
        time_former_value = 0;
        time_current_value = 0;
        sample_cnt = 0;
    }

    @Override
    public void onSensorChanged(SensorEvent event)
    {
        //Log.d("MySensor","onSensorChanged()\n");

        // Calculating the sample rate
        time_current_value = System.currentTimeMillis();
        long period = time_current_value - time_former_value;
        if ((time_former_value != 0) && (period != 0)) {
            m_sampleRate = (double) (1.0 / period) * 1000.0; // in Hz
            m_detector.setSampleRate(m_sampleRate);
        }

        /*if (sample_cnt == 100) //TODO: Delete this part before final use (inc. sample_cnt) -> only meant for debugging
        {
            Log.d("MySensor", "m_sampleRate:" + m_sampleRate + "\n");
            Log.d("MySensor", "time_current_value:" + time_current_value + "\n");
            Log.d("MySensor", "time_former_value:" + time_former_value + "\n");
            Log.d("MySensor", "currentTimeMillis:" + System.currentTimeMillis() + "\n");
            Log.d("MySensor", "period:" + period + "\n");
            sample_cnt = 0;
        }*/

        time_former_value = time_current_value;
        // Calculating the acceleration
        double acceleration = (Math.sqrt(event.values[0] * event.values[0] + event.values[1] * (event.values[1] + event.values[2] * event.values[2]))) - 9.81;
        m_detector.onNewSample(acceleration);
        sample_cnt++;
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        Log.d("MySensor","onAccuracyChanged()\n");
    }

    @Override
    public double getSampleRate() {
        return m_sampleRate;
    }

    @Override
    public void startSampling() {
        if (m_sensor != null) {
            if (sensorManager.registerListener(this, m_sensor, SensorManager.SENSOR_DELAY_GAME)) {
                Log.d("MySensor", "Bei Sensor angemeldet.\n");
            } else {
                Log.d("MySensor", "Kann dem Sensor keinen Beobachter hinzufügen\n");
            }
        }
    }

    @Override
    public void stopSampling() {
        if (m_sensor != null) {
            sensorManager.unregisterListener(this, m_sensor);
            Log.d("MySensor","Von Sensor abgemeldet.\n");
        }
    }


    public void connectSensorManager(SensorManager sensorManager){
        this.sensorManager = sensorManager;
        if (sensorManager.getSensorList(sensorType).size() == 0) {
            Log.d("MySensor", "Es gibt den Sensor nicht.\n");
            m_sensor = null;
        } else {
            m_sensor = sensorManager.getSensorList(sensorType).get(0);
        }
    }
}