WearOS 中 SensorManager 的问题

Question

我正在尝试获取加速度计数据，但无法在需要时获取。我想要每秒讲 20 次或多或少，这并不重要。问题是我收到的方式更多，比如尽可能多。我一直在查看文档，但我仍然得到每秒 100 次实现。这是代码：

public class MainActivity extends WearableActivity implements SensorEventListener {



private SensorManager mSensorManager;
private Sensor mAcceSensor;
private final static String TAG = "Wear MainActivity";
private TextView mTextView;
private Button myButton;
private ToggleButton activateSensors;
private int num = 1;
public boolean isOn;
private String datapath = "/message_path";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);
    mTextView =  findViewById(R.id.text);

    //send a message from the wear.  This one will not have response.
    myButton =  findViewById(R.id.wrbutton);
    activateSensors = findViewById(R.id.toggleButton);
    activateSensors.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
            if(isChecked) isOn = true;
            else isOn = false;
        }
    });

    myButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String message = "Hello device " + num;
            //Requires a new thread to avoid blocking the UI
            new SendThread(datapath, message).start();
            num++;
        }
    });

    // Register the local broadcast receiver to receive messages from the listener.
    IntentFilter messageFilter = new IntentFilter(Intent.ACTION_SEND);
    MessageReceiver messageReceiver = new MessageReceiver();
    LocalBroadcastManager.getInstance(this).registerReceiver(messageReceiver, messageFilter);

    mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
    mAcceSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

    // Enables Always-on
    setAmbientEnabled();
}

@Override
protected void onResume() {
    super.onResume();
    mSensorManager.registerListener(this, mAcceSensor,
            50000, 50000);
}

@Override
protected void onPause() {
    super.onPause();
    mSensorManager.unregisterListener(this, mAcceSensor);
}

@Override
public void onSensorChanged(SensorEvent sensorEvent) {
    if(sensorEvent.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
        String msg = Float.toString(sensorEvent.values[0]) +","+ Float.toString(sensorEvent.values[1]) +","+ Float.toString(sensorEvent.values[2])+","+getCurrentTimeStamp();
        if (isOn){
                new SendThread(datapath, msg).start();
        }
    }
}

public static String getCurrentTimeStamp(){
    try {

        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String currentDateTime = dateFormat.format(new Date()); // Find todays date
        return currentDateTime;
    } catch (Exception e) {
        e.printStackTrace();

        return null;
    }
}

@Override
public void onAccuracyChanged(Sensor sensor, int i) {

}

(Now a block about sending from one device to the other)
}

如您所见，我将侦听器定义为：mSensorManager.registerListener(this, mAcceSensor, 50000, 50000);

那应该每 50 毫秒给我一个实现，但我得到的更多。

Answer 1

我一直在四处寻找，发现自 2016 年以来的报告表明，在 WearOS 中，您在此处尝试的代码并不重要：

mSensorManager.registerListener(这个, mAcceSensor, 50000, 50000);

用了没关系

 mSensorManager.registerListener(this, mAcceSensor, SensorManager.SENSOR_DELAY_UI);

或 mSensorManager.registerListener(这, mAcceSensor, SensorManager.SENSOR_DELAY_FASTEST);

或者我的代码，它总是使用最快的采样率，大约 100 Hz。

Galaxy Nexus: Sensor Sampling Rate becomes faster when sampling more Sensors

最后我选择了一个低俗的方式：

@Override
public void onSensorChanged(SensorEvent sensorEvent) {
    nowDate = new Date();
    if(sensorEvent.sensor.getType() == Sensor.TYPE_ACCELEROMETER){
        String msg = Float.toString(sensorEvent.values[0]) +","+ Float.toString(sensorEvent.values[1]) +","+ Float.toString(sensorEvent.values[2]);
        if (isOn && (nowDate.getTime() -startDate.getTime()) >= 40){
                startDate = nowDate;
                String timeStamp = dateFormat.format(nowDate);
                msg = msg +","+timeStamp;
                new SendThread(datapath, msg).start();
        }
    }
}

它有效，虽然不完美，但已经足够好了。似乎我在 if 条件中选择的值并不重要，我已经尝试了 40、50 和 60，并且都几乎完美地达到了 16-17Hz。我也尝试过从 SENSOR_DELAY_UI 更改为 SENSOR_DELAY_FASTEST，我得到了相同的结果，始终是 16-17Hz，所以这不是选择的问题。

我希望这对遇到同样问题的人有所帮助，如果有更时尚的做法，我会阅读。

WearOS 中 SensorManager 的问题

Problems with SensorManager in WearOS

android

wear-os

android-sensors