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From: Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand>
Newsgroups: comp.lang.java.programmer
Subject: Android Sensor Coordinates
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Date: Fri, 01 Apr 2011 13:03:42 +1300
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:2675

The diagram of the linear sensor coordinate system here 
<http://developer.android.com/reference/android/hardware/SensorEvent.html> 
seems to be wrong.

I have a test program running on my HTC Desire (Android 2.2), showing me 
values from the accelerometer. As it lies horizontally, face-up on my desk, 
the Z value is positive (around 9.8, as you would expect). But that diagram 
says that positive Z is up, not down.

I tilt the phone to the left, and the X value increases. Tilt to the right, 
it decreases. But the diagram says positive X is to the right, not the left.

Tilt it up, the Y value increases. Hold it vertical, with the display upside 
down, and the Y value shows negative. Again, completely the opposite to the 
diagram.