View Single Post
  #3   Spotlight this post!  
Unread 30-01-2009, 10:55
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,770
Al Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond repute
Re: Common Ground for DSC

Eric,
Although electrically that would seem to work, you would need to follow other electrical system rules for combining wires, insulating same and connecting to the DSC. The wiring convention provided is designed for you to be able to use commonly available PWM cables for interconnect. In general digital inputs will come from different locations on the robot, it would seem that a common point for digital inputs is contrary to good practice. Additionally, using the intended interconnect method will give slightly better noise immunity by providing a separate path for noise on each cable directly to the DSC rather than comprimising all digital inputs with a common ground outside of the DSC. Finally, and more importantly, a common point outside of the DSC gives a single point failure for all digital inputs if the wire breaks or becomes disconnected.
__________________
Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
________________________
Storming the Tower since 1996.