Example for BeatDetect Minim

Question

I am using this code to record the current sound. I need now some processing to detect the beat from music. I want a LED go on/off according the incoming music. I think BeatDetect is an useful library for my project, however I cannot find a good example. Can anyone give me an easy example to use? Or a reference?

public void start() {
    initializeMediaRecorder();

    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            notifySample(getAmplitude());

            handler.postDelayed(this, 150);
        }
    }, 150);
}

public void stop() {
    handler.removeCallbacksAndMessages(null);

    if (mediaRecorder != null) {
        mediaRecorder.stop();
        mediaRecorder.reset();
        mediaRecorder.release();
        mediaRecorder = null;
    }
}

private double getAmplitude() {
    if (mediaRecorder != null) {
        return mediaRecorder.getMaxAmplitude();
    } else {
        return 0;
    }
}

private void initializeMediaRecorder(){
    try {
        if(mediaRecorder == null) {
            mediaRecorder = new MediaRecorder();
            mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
            mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
            mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
            mediaRecorder.setOutputFile("/dev/null");
            mediaRecorder.prepare();
            mediaRecorder.start();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}