CODEWITHSUNDEEP
androidcrashaccelerometerandroid-sensors
mabdrabo
mabdrabo

Reputation: 1060

AccelerationSensor.accelerationchanged() making app slow

in my app, i use the AccelerationSensor.accelerationchanged(xAccel, yAccel, zAccel) API the problem is the method is called every o.oooo1 change in any axis, so the app becomes very slow, some times even becomes "non-responding"

Is there a way to check if the integer part has changed and let away any decimal change?

Upvotes: 0

Views: 127

Answers (2)

draksia
draksia

Reputation: 2371

This is what I am doing, in my onStartCommand() of my service

mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);

This is the function I am handling my data, it is pretty light weight but it should give you an idea using a threshold. In my case I really just need to know the device a bit, in my case it turned out the differenceValue neeeded to be about 1.75G but it might be different for you.

@Override
public void onSensorChanged(SensorEvent event) {


    if(last[0] == 0.0f &&
       last[1] == 0.0f &&
       last[2] == 0.0f){

        last[0] = event.values[0];
        last[1] = event.values[1];
        last[2] = event.values[2];

        return;
    }

    float diff = 0f;

    if(Math.abs(last[0] - event.values[0]) > differenceValue ||
       Math.abs(last[1] - event.values[1]) > differenceValue ||
           Math.abs(last[2] - event.values[2]) > differenceValue){

        Log.d(TAG,"G values are "+event.values[0]+" "+event.values[1]+" "+event.values[2]);
        Log.d(TAG,"Last G values are "+last[0]+" "+last[1]+" "+last[2]);



        diff = Math.abs(last[0] - event.values[0]);

        if(diff < Math.abs(last[1] - event.values[1])){
           diff = Math.abs(last[1] - event.values[1]);
        }

        if(diff < Math.abs(last[2] - event.values[2])){
           diff = Math.abs(last[2] - event.values[2]);
        }

        Log.d(TAG,"Sensor difference: "+diff);

        //Do what ever processing you need here

    }

    last[0] = event.values[0];
    last[1] = event.values[1];
    last[2] = event.values[2];
}

Upvotes: 1

Gabe Sechan
Gabe Sechan

Reputation: 93708

When you register a listener for a sensor it allows you to set a frequency. Use a slower frequency.

Upvotes: 1

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