Quote:
Originally Posted by ArtPE
300 hz is plenty...that's a sample every 3.3 ms...generally speaking you need to sample at 2x the frequency of the signal you are trying to capture data for...
so if the shift is 30 ms, 3.3 is 9x's...
3.3 is theoretically enough to capture 8 ms...
Nyquist-Shannon
If a function f(t) contains no frequencies higher than W cps, it is completely determined by giving its ordinates at a series of points spaced 1/(2W) seconds apart.
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I think everyone is on the same page here, and we all agree that greater frequency would be helpful, but I'll point this out anyway. There seem to be at least two "stages" to each shift, which are necessarily significantly shorter than the total 30 ms shift time. To better break down the shifts and capture/measure what exactly is happening, more sample points certainly would be very helpful.
In any event, great job getting this up and running, swamp. Your initial efforts have already yielded some very interesting data and, as usual with these types of things, raised almost as many questions as they've answered. I'm curious to see the next stage -- hopefully, Ken or someone can fab up a mount that is successful in dialing out much of the noise.
Great job, swamp.