Hi:

The thing I find very interesting is that the newer 3-axis accelerometers are 
just starting to be used for free fall detection.  The first generation units 
from Freescale had that function in the eval board.  Within a few inches of 
free fall from a static drop a LED turns on indicating free fall.  The key 
applications may be HDD head parking in laptop computers, human fall detection, 
cell phone menu navigation.   App Note on Free Fall Sensing:
http://www.freescale.com/files/sensors/doc/app_note/AN3459.pdf?tid=tslpGSEL

But the eval module can be fooled by dynamics such as a spin ball toss which 
requires sensing other things.  Free scale has
http://www.prc68.com/I/Sensors.shtml

For the 8-Ball video (8 MB) see:
http://www.freescale.com/files/multimedia/TSP-12837_8Ball_071008.wmv
If you know of documentation on the 8-Ball or where to get one let me know.

Another interesting thing about gyros is that there long term drift rate is a 
function of the volume of the sensor independent of the type of sensor.  I 
posted at table at:
http://www.prc68.com/I/Sensors.shtml#Gyroscopic

-- 
Have Fun,

Brooke Clarke
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