======================[ Readings ]======================

https://developer.android.com/guide/topics/sensors/sensors_overview.html

In-class examples: 
  examples/Proximity/
  examples/Compass/
  
Proximity and orientation sensors are explained in:
  https://developer.android.com/guide/topics/sensors/sensors_position.html

Android engineer blog explaining the new orientation API:
  https://android-developers.googleblog.com/2010/09/one-screen-turn-deserves-another.html

New Android API based on fusing the accelerometer and Earth's magnetic field 
(a.k.a. magnetometer) sensors:
  https://developer.android.com/reference/android/hardware/SensorManager.html#getOrientation(float%5B%5D,%20float%5B%5D)
  https://developer.android.com/reference/android/hardware/SensorManager.html#getRotationMatrix(float%5B%5D,%20float%5B%5D,%20float%5B%5D,%20float%5B%5D)

===============[ Using raw accelerometer readings for a game ]===============

See https://github.com/masayukig/tiltmazes, GameEngine.java, 
  https://github.com/masayukig/tiltmazes/blob/master/src/com/lecz/android/tiltmazes/GameEngine.java
for the use of the raw accelerometer data. Lines 79--98 grab the
accelerometer measurement to determine the direction of rolling the
ball. The sensor object is acquired at lines 118--121.

The ACCEL_THRESHOLD parameter (line 51 of GameEngine.java) is the key
to the user experience.  In the original game it's set to 2 to detect
the natural tilting motion most users will use to tilt the screen to
get the ball rolling.  At 10, the ball gets really sticky; you'll need
to forcefully tap the phone to get it rolling. At 20, you'd need to
forcefully jerk the phone in the desired direction; smooth tilting
will not do the trick. Try these settings to see what's comfortable
for you.

===============[ Side notes ]===============

Fork bomb:  
  https://askubuntu.com/questions/159491/why-did-the-command-make-my-system-lag-so-badly-i-had-to-reboot