Android Things Bluetooth Audio Test

test.java

// None of these 3 methods currently produce any sound, but all work under Android N smartphone

// * Board: Raspberry Pi Model 3 | OS: Android Things DP41
// * Android shows BT speaker as "connected" under: $ am start -a android.settings.BLUETOOTH_SETTINGS (seen via Vysor)
// * No active HDMI or audio jack connection (just ethernet and power)
// * Example file encoded as WAV stored in raw resource directory

// 1. Using MediaPlayer API

MediaPlayer mediaPlayer = MediaPlayer.create(this, R.raw.chime);
mediaPlayer.setVolume(100,100);
mediaPlayer.start();

// 2. Using SoundPool API
// Also outputs logcat error line: "Failed to open libwvm.so"

final SoundPool sp = new SoundPool(5, AudioManager.STREAM_MUSIC, 0);
final int soundId = sp.load(this, R.raw.chime, 1);

sp.setOnLoadCompleteListener(new SoundPool.OnLoadCompleteListener() {
            @Override
            public void onLoadComplete(SoundPool soundPool, int sampleId, int status) {
                sp.play(soundId, 1, 1, 0, 0, 1);
            }
        });

// 3. Using Text-to-Speech API

mTtsEngine = new TextToSpeech(this,
                new TextToSpeech.OnInitListener() {
                    @Override
                    public void onInit(int status) {
                        if (status == TextToSpeech.SUCCESS) {
                            mTtsEngine.setLanguage(Locale.US);
                        } else {
                            Log.w("MainThingsActivity", "Could not open TTS Engine (onInit status=" + status
                                    + "). Ignoring text to speech");
                            mTtsEngine = null;
                        }
                    }
                });

        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                mTtsEngine.speak("Hello World", TextToSpeech.QUEUE_ADD, null, "com.example.utterance");
            }
        }, 1000);