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Unread 24-02-2016, 02:59
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Andrew Phelps
FRC #1318 (Issaquah Robotics Society)
Team Role: Mechanical
 
Join Date: Mar 2014
Rookie Year: 2012
Location: United States
Posts: 77
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Encoders direct driven by mini cim? Is it bad?

A mentor said we can't put an encoder on our shooter, driven by mini CIMs, because it would overload the code or something. Being the one who designed and built the shooter, I've been kicking myself in the butt trying to figure out how to get some type of low res encoder on it. So far we've tried a Hall effect sensor and a metal proximity detector, with magnets on the shaft and bolt heads on a hex hub, respectively. Both didn't work.

There is a 20 tick encoder on andymark that mounts directly to a mini cim. At this point, I'm willing to try it despite what our main technical mentor said in week three. My question: would an encoder reading downwards of 2,000 cps (counts per second, 5,800 RPM @ 20 ticks/rotation = ~2,000 cps) overload the code/RoboRIO? I'd like to say no since the RoboRIO operates in the MHz (I think) and that should be plenty but id love it if you would share your experiences.

It has been tossed around that we use an algorithm based on battery voltage to decide how much voltage to give the shooter. I really don't like this option, I'd rather run it open loop since battery voltage is constantly fluctuating.
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team1318.org

2016: Flight Director, Alliance/Match Strategy
2015: Mechanical Lead
2013-2014: Fabrication

2016: 2x district finalists, Quality, DCMP Entrepreneurship Awards
2015: 3x district winners, Innovation in Control, Creativity, Team Spirit awards
2014: Galileo Division finalists, PNW District Championship winners, 1x district winners, District Chairman's, Innovation in Control, Entrpreneurship awards
2013: Entrepreneurship award

Last edited by aphelps231 : 24-02-2016 at 11:42.