On Tue, 06 Jan 2004 20:27:08 GMT, "Vic Fraenckel" wrote:

wrote in message
.. .
| Oddly enough, my goals are the same. I intend to retire this spring, and
buy a boat for coastal
| cruising. One project I have in mind is a "wave-meter", i.e., a device
which will tell me how high
| the waves are....swells and wind chop. Roll and pitch should be do-able
also.
|
| My approach is the same as below. But, as pointed out in another post,
calibration is the problem.
|

Norm,

There is no calibration problem with the ADXL202. What is a problem, at
least with my application, is insuring that the accelerometer is mounted
perpendicular to the roll and pitch axes. I am attempting to mount the ADXL
on a telescope (not astronomical) to measure the inclination of the optical
axis of the system. After trying to align the accelerometer mrchanically to
the axes, I am now trying to write a routine to compute the off-axisness and
use the results to compensate for the mis-alignment.

Have you considered integrating the signal? I'd suspect that on average,
"up" would be the 'average' of the roll and pitch over a period of time.
Interesting engineering problem.

I'll check out usdigital's web site...thanks.

snip


HTH

Vic