Is there a way for me to create a start and stop button for my android acclerometer to show data?

Question

I am a beginner with Android, I have created an application with an Accelerometer, but right now the accerelometer constantly runs. Is there a way for me to create a start button so I can record data and a stop button where once pressed the axis data shows on the screen?

Here is my code so far,

package com.example.physio4knee2;


import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

public class movement extends Activity implements SensorEventListener {

    private float mLastX, mLastY, mLastZ;
    private boolean mInitialized;
    private SensorManager mSensorManager;
    private Sensor mAccelerometer;
    private final float NOISE = (float) 2.0;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.movement);
        mInitialized = false;
        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        mSensorManager.registerListener(this, mAccelerometer , SensorManager.SENSOR_DELAY_NORMAL);
    }

    protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
    }

    protected void onPause() {
        super.onPause();
        mSensorManager.unregisterListener(this);
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // can be safely ignored for this demo
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
           long timestamp = event.timestamp;
            float value = event.values[0];

            // do something with the values

        TextView tvX= (TextView)findViewById(R.id.x_axis);
        TextView tvY= (TextView)findViewById(R.id.y_axis);
        TextView tvZ= (TextView)findViewById(R.id.z_axis);
        ImageView iv = (ImageView)findViewById(R.id.image);
        float x = event.values[0];
        float y = event.values[1];
        float z = event.values[2];
        if (!mInitialized) {
            mLastX = x;
            mLastY = y;
            mLastZ = z;
            tvX.setText("0.0");
            tvY.setText("0.0");
            tvZ.setText("0.0");
            mInitialized = true;
        } else {
            float deltaX = Math.abs(mLastX - x);
            float deltaY = Math.abs(mLastY - y);
            float deltaZ = Math.abs(mLastZ - z);
            if (deltaX < NOISE) deltaX = (float)0.0;
            if (deltaY < NOISE) deltaY = (float)0.0;
            if (deltaZ < NOISE) deltaZ = (float)0.0;
            mLastX = x;
            mLastY = y;
            mLastZ = z;
            tvX.setText(Float.toString(deltaX));
            tvY.setText(Float.toString(deltaY));
            tvZ.setText(Float.toString(deltaZ));
            iv.setVisibility(View.VISIBLE);
            if (deltaX > deltaY) {
                iv.setImageResource(R.drawable.horizontal);
            } else if (deltaY > deltaX) {
                iv.setImageResource(R.drawable.vertical);
            } else {
                iv.setVisibility(View.INVISIBLE);
            }
        }
    }
}

Answer 1

create a button and it's on click listener, like that (stop button):

stopButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
       mSensorManager.unregisterListener(this);
    }
});

To start recording use:

 startButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
          mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);

        }
    })