View Single Post
  #72   Spotlight this post!  
Unread 10-01-2005, 19:57
Greg Ross's Avatar
Greg Ross Greg Ross is offline
Grammar Curmudgeon
AKA: gwross
FRC #0330 (Beach 'Bots)
Team Role: Mentor
 
Join Date: Jun 2001
Rookie Year: 1998
Location: Hermosa Beach, CA
Posts: 2,245
Greg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond reputeGreg Ross has a reputation beyond repute
Send a message via AIM to Greg Ross Send a message via Yahoo to Greg Ross
Re: What do you think about how easy theyre making programming?

Quote:
Originally Posted by stephenthe1
[T]he only thing is that our encoder's "b" phase isn't wired yet. [W]ill this mess it up?
Yeah, I would guess not having the B line connected will keep your code from operating as you expect. (Since you don't explain how you expect it to operate, I will make some assumptions.)

Not having the B line connected will keep the software from knowing which direction the encoder is turning. If you're lucky(?), the encoder interrupt handler will DECREMENT the counter on each interrupt, so that the arm control will appear to operate correctly for a while (with the exception that the arm won't stop where you think it should be when the encoder counter = 12.) After the encoder counter overflows, the arm will stop responding, because the counter will now be greater than 12.

If, on the other hand, the interrupt handler INCREMENTS the counter instead of decrementing it, I expect that the arm will stop responding after just a slight twitch, no mater which direction you move the joystick. (I say just a slight twitch, because 12 seems like such a small number when you're talking about encoders. I could be wrong, and your encoder might actually be of low enough resolution that a count of 12 will actually measure a reasonable arm rotation.)
__________________
Greg Ross (The Grammar Curmudgeon formerly known as gwross)
S/W Engineer, Team 330, the Beach 'Bots
<--The Grammar Curmudgeon loves this cartoon.
“Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!" Hunter S. Thompson
"Playing a practical joke means doing something mean and calling it funny." Me