Question

I’m trying to find out the force of which a button is pressed with the on-board accelerometer.
I figured i’ll have to do a series of readings and then compare the values.
My attempt at it was something like this:

  velButton.setOnTouchListener(new OnTouchListener()
  {
        public boolean onTouch(View view, MotionEvent event)
        {
        int velocity = 0;

        switch (event.getAction())
        {
            case MotionEvent.ACTION_DOWN:

                velocity = getVelocity();
                velocityView.setText("This is the velocity: " +  velocity);
                break;

        }

        return false;
        });
    }

protected int getVelocity()
{
    float accent = 0;

    int velocity;


    try
    {
    accent = getHighestValue();
} catch (InterruptedException e)
{
    // TODO Auto-generated catch block
    e.printStackTrace();
}

velocity = (int) accent;

return velocity;
}


protected float getHighestValue()  throws InterruptedException
{
float highest;
float[] value = new float[20];
String txt = "";

for(int i = 0; i < value.length; i++)
{
    Thread.sleep(1);
    value[i] = accelerometer_z;
    txt += "Reading at: " + i + " ms returns: " + value[i] + "\n";
}

Arrays.sort(value);
highest = value[19];

textView2.setText(txt);

return highest;
}

The float accelerometer_z is initialized in my main activity and is updated continually through onSensorChanged.

My problem here is that I don’t get a series of values, I only get One value from the for-loop in my getHighestValue method.

Cheers
/M

Added onSensorChanged:

@Override
  public void onSensorChanged(SensorEvent event) 
  {
if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) 
{
        getAccelerometer(event);
}

  }

  private void getAccelerometer(SensorEvent event) 
  {

float[] value = event.values;

// Movement
 accelerometer_x = value[0];
accelerometer_y = value[1];
accelerometer_z = value[2];


 accelationSquareRoot = (accelerometer_x * accelerometer_x + accelerometer_y * 
                            accelerometer_y + accelerometer_z * accelerometer_z)
    / (SensorManager.GRAVITY_EARTH * SensorManager.GRAVITY_EARTH);


long actualTime = System.currentTimeMillis();
if (accelationSquareRoot >= 2) 
{
  if (actualTime - lastUpdate < 200) 
  {
    return;
  }
  lastUpdate = actualTime;


}

}

Answer 1

It seems that only one event handler can be run at the same time and that’s the reason why I’m only getting a single value from the gethighestValue.
The onSensorChanged will never be allowed to make a new reading as long as the motionEvent in the onTouch is waiting for new input.

I solved this by letting the onSensorChanged implement a method like this:

private void getAccelerometer(SensorEvent event)
    {
        float[] value = event.values;

        float accelerometer_x = value[0];
        float accelerometer_y = value[1];
        float accelerometer_z = value[2];

        accReadingZ.add(accelerometer_z);

        while(accReadingZ.size() > LIST_SIZE)
            accReadingZ.removeFirst();
    }

accReadingZ is here a class member with a size of 10 elements.

I can now use Collections.max(accReadingZ) to get the highest value in the series of readings.