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Unread 16-01-2012, 12:11
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Re: Potentiometer vs. Encoder

Quote:
Originally Posted by jeremypg399 View Post
Remember that the ADC on the cRIO is 10 bit. 1024 unique values.


While the ADC on the cRIO analog module is actually 12 bits, it's in range of -10v to 10v. Only 10 bits are in the range of 0-5v, so it's better to use 10 bits in your calculations.



Quote:
Originally Posted by Mr V View Post

An encoder can tell you the rpm of a shaft or be used on a device with unlimited rotation to move a certain number of steps relative to where you start counting. It can be useful in autonomous to have your robot move a specific distance from its starting position or to maintain a set rpm with a varying load.


It's also possible to get continuous turn potentiometers and use them for everything you can use a encoder for. The following whitepaper goes through how to do this. http://www.chiefdelphi.com/media/papers/1743



Quote:
Originally Posted by eannevelink View Post
I'm not exactly sure where this is coming from, but I read somewhere that encoders are more precise that potentiometers. Is this true? If so, why would you use a potentiometer over an encoder except for the fact that potentiometers are absolute.


I will use a potentiometer every time, unless there is a compelling reason to use an encoder. Potentiometers are cheaper, and in my experience is more robust. Rarely have I found the accuracy of a potentiometer to be a problem in FIRST applications.

Last edited by Joe Ross : 16-01-2012 at 20:45.
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