The Nyquist theorem states that you need to sample at least 2x the frequency you are sampling to be able to capture it. However, you'll also get various spurious beat signals which can be large compared to the actual signal if you try to push too close to that 2x. That is, if you sample 1 Hz faster than 2x the signal, you'll see a spurious 1 Hz signal due to sampling at different points in the signal's cycle. You can filter that out, and lose the low-end, or you can increase the sample rate and filter the input.
This is just about THE most fundamental fact about digitized signal processing, so it'll be worth reading up on it and getting comfortable with the implications. On Apr 9, 3:54 am, Jason LeBlanc <[email protected]> wrote: > How much faster? > > On Apr 8, 2010 7:32 PM, "BobG" <[email protected]> wrote: > > If you move the phone left and right when looking at the screen, thats > moving in the x axis, so if you take sanples faster than you are > shaking it, as ordained by Mr Nyquist, you will see the accel > increasing, then slowing down, stopping, and accelerating back the > other way. The info you asked for is in there... which way it goes > first... +x direction or -x direction. > > -- > > You received this message because you are subscribed to the Google > Groups "Android Developers" group... -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en To unsubscribe, reply using "remove me" as the subject.
