CODEWITHSUNDEEP
javaandroidproximitysensor
Steven
Steven

Reputation: 1098

Proximity sensor on physical Android device

I am seeing proximity sensor detection behavior on physical Android devices that is so far off from what I am expecting that I must be missing some foundational huge thing. Here's what I see:

I wrote a simple app that displays the proximity sensor value.

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/proxValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="60dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</LinearLayout>

MainActivity.java:

public class MainActivity extends AppCompatActivity implements SensorEventListener {

  TextView proxValue;
  SensorManager sensorManager;
  Sensor proximitySensor;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    proxValue = (TextView) findViewById(R.id.proxValue);
    sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    proximitySensor = sensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
  }

  @Override
  protected void onPause() {
    super.onPause();
    sensorManager.unregisterListener(this);
  }

  @Override
  protected void onResume() {
    super.onResume();
    sensorManager.registerListener(this, proximitySensor, SensorManager.SENSOR_DELAY_NORMAL);
  }

  @Override
  public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_PROXIMITY) {
      proxValue.setText(String.valueOf(event.values[0]));
    }
  }

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

}

In the device emulator, when I move the virtual sensor's proximity slider around, it works as I would expect: the float value displayed on screen corresponds to the slider value.

Video of emulator behavior

However, when I run this on a physical device (devices tested listed below), I see two unexpected behaviors:

  1. The proximity detection is triggered not by me waving my hand in front of the device (near the top), but rather when by placing my palm anywhere on the screen
  2. It only displays 0.0 or 5.0.

Video of device behavior

Edit: to clarify, the behavior I expected is that when my hand waves close to the front of the phone (without making physical contact, say hovering 1"), the proximity sensor is able to indicate that it's 1" away. Think, for example, a push-up tracker app that you lay on the ground and do push ups on top of, that uses the proximity sensor to determine that you've sufficiently lowered to count as a push up.</edit>

Meanwhile, the phone app's proximity sensor behaves correctly/as-expected: while in a phone call, if I place the phone near my head (without making physical contact), the screen will black out.

Related, I tried this proximity sensor test app with same problematic results on physical devices.

Android version 14/API 34

Devices tested:

Thanks in advance for any help.

Upvotes: 0

Views: 272

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