
30-01-2010, 23:36
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Registered User
 FRC #0330 (Beachbots)
Team Role: Engineer
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Join Date: Jun 2001
Rookie Year: 1997
Location: Los Angeles, CA
Posts: 8,560
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Re: How Precise and Accurate is the Analog In on the Crio?
Quote:
Originally Posted by EricVanWyk
I'll let someone else chime in on one and three, but I'll rant about two for a moment. Oversampling assumes an additive noise signal that pushes the perceived value around the threshold. I like to imagine it thusly: I have a ruler that is only capable of measuring something to the nearest inch, but I need it to the nearest quarter inch. If I measure it a bunch of times, I'll still only get it to the nearest inch. However, I repeatedly randomly offset the ruler by some amount and average all the measurements. As long as my random offsets average out to zero their impact averages out to zero. BUT, they did allow me to get better resolution, because they "unstuck" my ruler.
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Here's a nice whitepaper about oversampling which gets deeper into this issue.
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