android - 无法让加速度计感知震动事件

Question

我正在尝试将某些功能与“摇动”事件联系起来。我在这里使用了教程:

http://www.vogella.com/articles/AndroidSensor/article.html

http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/os/Sensors.html

我正在使用 OpenIntents 的 SensorSimulator 进行测试.我能够将模拟器连接到 SensorSimulator。当我在模拟器中移动设备时，模拟器上的加速度计读数与模拟器的读数完全一致。

在我的代码中，我添加了一些日志语句，例如:

public class ShakeEventListener implements SensorEventListener {

private void getAccelerometer(SensorEvent event) {

    float[] values = event.values;
// Movement
float x = values[0];
float y = values[1];
float z = values[2];

float accelationSquareRoot = (x * x + y * y + z * z)
        / (SensorManager.GRAVITY_EARTH * SensorManager.GRAVITY_EARTH);
long actualTime = System.currentTimeMillis();
Log.i("onSensorChanged", "accelationSquareRoot: " + accelationSquareRoot);

if (accelationSquareRoot >= 2) //
{
    if (actualTime - lastUpdate < 200) {
    return;
    }
    lastUpdate = actualTime;

        // Shake Detected
    Log.i("onSensorChanged", "Shakie Shakie!");
    }
}

public void onSensorChanged(SensorEvent se) {

    Log.d("onSensorChanged", "X: " + se.values[SensorManager.DATA_X] + 
               " Y: " + se.values[SensorManager.DATA_Y] + 
               " Z: " + se.values[SensorManager.DATA_Z]);

    if (se.sensor.getType() == Sensor.TYPE_ACCELEROMETER) 
    {
    getAccelerometer(se);
    }
}
}

如果我在模拟器中移动设备，log cat 中的输出似乎没有改变。它总是显示这些读数(读数每分钟不断更新多次，但它们始终相同):

05-22 15:09:07.717: I/onSensorChanged(686): accelationSquareRoot: 1.0006835
05-22 15:09:08.518: D/onSensorChanged(686): X: 0.0 Y: 9.77622 Z: 0.813417
05-22 15:09:08.518: I/onSensorChanged(686): accelationSquareRoot: 1.0006835

我尝试了 APIDemos 示例 sensors.java 但它也注册了相同的行为。我可能会错过什么？

Answer 1

这是适用于我的应用的加速度计代码:

// shake
private SensorManager mSensorManager;
private float mAccel; // acceleration apart from gravity
private float mAccelCurrent; // current acceleration including gravity
private float mAccelLast; // last acceleration including gravity


    //Shake
    private final SensorEventListener mSensorListener = new SensorEventListener() {
        int count = 0;
        public void onSensorChanged(SensorEvent se) {

          float x = se.values[0];
          float y = se.values[1];
          float z = se.values[2];
          mAccelLast = mAccelCurrent;
          mAccelCurrent = (float) Math.sqrt((double) (x*x + y*y + z*z));
          float delta = mAccelCurrent - mAccelLast;
          mAccel = mAccel * 0.9f + delta; // perform low-cut filter
          if (mAccel > 5) {
              //do something
          }
        }

        public void onAccuracyChanged(Sensor sensor, int accuracy) {

        }
      };

这是 source我是如何得到这段代码的。