View Single Post
  #3   Spotlight this post!  
Unread 02-02-2016, 15:24
jhersh jhersh is offline
National Instruments
AKA: Joe Hershberger
FRC #2468 (Appreciate)
Team Role: Mentor
 
Join Date: May 2008
Rookie Year: 1997
Location: Austin, TX
Posts: 1,006
jhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond reputejhersh has a reputation beyond repute
Re: Encoder resolution on fast turning shafts

Quote:
Originally Posted by Tom Line View Post
There was a very lengthy discussion about jitter, sampling, and RPM calculation in 2012. To make a long discussion short, if you are using the period function in LabVIEW, you may actually be better off with a 1 count per rotation encoder to maximize the period and make your RPM calculation more accurate.
While much of that discussion still holds to some extent, much of it is not all that applicable given the roboRIO's vastly faster DIO, unless you have a blindingly fast encoder signal.

Quote:
Originally Posted by Tom Line View Post
We used it very successfully in 2012, and 2013. This will also eliminate any worries you may have about loading the roborio.
The roboRIO and the cRIO does / did all quadrature decoding in the FPGA. It incurs no more or less load on the system sitting unswitched vs. switching quickly.

Last edited by jhersh : 02-02-2016 at 18:01.