import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
public void init(String gpioPin) throws IOException {
    buzzer = new Speaker(gpioPin);
    buzzer.stop(); // in case the PWM pin was enabled already

    handlerThread.start();
    handler = new Handler(handlerThread.getLooper()) {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            try {
                buzzer.stop();
                if (msg.what == HANDLER_MSG_PLAY) {
                    buzzer.play(msg.arg1);
                    handler.sendEmptyMessageDelayed(HANDLER_MSG_STOP, 800);
                }
            } catch (IOException e) {
                Log.e(TAG, "Buzzer error", e);
            }
        }
    };
}
 

import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    try {
        mSpeaker = new Speaker(BoardDefaults.getPwmPin());
        mSpeaker.stop(); // in case the PWM pin was enabled already
    } catch (IOException e) {
        Log.e(TAG, "Error initializing speaker");
        return; // don't initilize the handler
    }

    mHandlerThread = new HandlerThread("pwm-playback");
    mHandlerThread.start();
    mHandler = new Handler(mHandlerThread.getLooper());
    mHandler.post(mPlaybackRunnable);
}
 

import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
public Buzzer(Speaker speaker, Handler stopHandler) throws IOException {
    this.speaker = speaker;
    this.stopHandler = stopHandler;
    stopRunnable = new Runnable() {
        @Override
        public void run() {
            try {
                stop();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    };
}
 

import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
@Override
protected void onCreate(@Nullable final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    try {
        speaker = new Speaker(BoardDefaults.getPwmPin());
        presenter = new PianoPresenter(this, (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE),
                getString(R.string.service_id), getPackageName());
    } catch (IOException e) {
        throw new IllegalArgumentException("Piezo can't be opened, lets end this here.");
    }
}
 

import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    PeripheralManagerService service = new PeripheralManagerService();
    Log.d(TAG, "Available GPIO: " + service.getGpioList());
    Log.d(TAG, "Available I2C: " + service.getI2cBusList());
    Log.d(TAG, "Available SPI: " + service.getSpiBusList());
    Log.d(TAG, "Available PWM: " + service.getPwmList());
    Log.d(TAG, "Available UART: " + service.getUartDeviceList());

    startTime = System.currentTimeMillis();

    try {
        mLedGpio = service.openGpio(GPIO_LED_PIN_NAME);
        // Step 2. Configure as an output.
        mLedGpio.setDirection(Gpio.DIRECTION_OUT_INITIALLY_LOW);

        // Step 1. Create GPIO connection.
        mButtonGpio = service.openGpio(GPIO__BUTTON_PIN_NAME);
        // Step 2. Configure as an input.
        mButtonGpio.setDirection(Gpio.DIRECTION_IN);
        // Step 3. Enable edge trigger events.
        mButtonGpio.setEdgeTriggerType(Gpio.EDGE_FALLING);
        // Step 4. Register an event callback.
        mButtonGpio.registerGpioCallback(mCallback);

        mSpeaker = new Speaker(BUZZER_PIN_NAME);
        mSpeaker.stop(); // in case the PWM pin was enabled already

        //mLedMatrix = new LEDMatrix(LED_MATRIX_RCLK_PIN_NAME, LED_MATRIX_SRCLK_PIN_NAME, LED_MATRIX_DI_PIN_NAME);
        //mLedMatrix.setFlipVertical(true);

        //mSegDisplay = new TM1838Driver(LED_SEG7_CLK_PIN_NAME, LED_SEG7_STB_PIN_NAME
        //        , LED_SEG7_DIO_PIN_NAME, TM1838Driver.BRIGHTNESS_LOW);
        mSegDisplay = new TM1838Driver("SPI0.0", TM1838Driver.BRIGHTNESS_MED);

        /*mLedBar = new LEDBar(LED_BAR_DI_PIN_NAME, LED_BAR_DCLK_PIN_NAME, 10);
        mLedBar.clear();*/

        /*mDisplay = new NumericDisplay(DISPLAY7_DATA_PIN_NAME, DISPLAY7_CLK_PIN_NAME);
        mDisplaySelect = service.openGpio(DISPLAY7_SELECT_PIN_NAME);
        mDisplaySelect .setDirection(Gpio.DIRECTION_OUT_INITIALLY_HIGH);*/
    } catch (IOException e) {
        Log.e(TAG, "Error on PeripheralIO API", e);
    }

    THEME = MusicNotes.DRAMATIC_THEME;
}
 

import com.google.android.things.contrib.driver.pwmspeaker.Speaker; //导入依赖的package包/类
public static Speaker openPiezo() throws IOException {
    return new Speaker(BOARD.getPiezoPwm());
}