Team update 19

Team update 19 has been posted:

http://usfirst.org/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2011_Assets/Team_Updates/Team_Update_19.pdf

It contains a new cRio update for teams using CAN.

Also, an explanation of how the tower triggering mechanism works.

No major game-changing rules. I’m fine with that. MESSAGE TO ALL TEAMS: GET THE NEW C-RIO UPDATE. WE’VE HAD TIMES IN THE PAST WHERE ONLY THE NEWEST VERSIONS WOULD WORK

The tower triggering explanation should end speculation on how it works. I’d opine that a 1 mSec debounce buffer is not an issue: If your minibot hits the target (and not the bolts) the tower will trigger.

Week 3 starts soon, I’m still hoping to hear any reports of towers not reasonably triggering.

Week 3 has been and gone. I hope you didn’t forget to attend a Regional Don! :slight_smile:

I’m a little envious from the Team Update #19 quote
“this update has been tested with a number of FRC robots in competition”
We remained stationary in a semi-final match due to the exact conditions which this bug fixes (and a lack of defensive code on our part) and I’d have been prepared to take the risk of beta testing the fix had it been available to us.

For those of you that aren’t able to click the link, here is the portion about tower triggering:

Interest has been expressed by many teams on how the TRIGGERING of the TOWERS is
monitored. The following is a more technical explanation.

Each TOWER in LOGOMOTION has a dedicated module that monitors the trigger mechanism for
that TOWER and controls the lights at the top. The trigger mechanism activates at ~0.25 inches of
plate movement. The control module has a built-in noise buffer of 1ms. Any input signal longer than
the noise buffer is immediately time-stamped and reported back to the central field controller. This
central field controller then processes the received data every 5ms or less. Once the field controller
sees a TOWER as TRIGGERED, it assigns a finish place to that TOWER (1st, 2nd, 3rd, or 4th)
depending on the state of the remaining three TOWERS

So, can someone explain what all of this means? From what I understand, your minibot must move the top plate approximately 1/4" and hold the plate in the triggered position for longer than 1ms?

From helping with the Towers at the Tel Aviv Regional, I learned that the triggering mechanism is simply 2 pieces of aluminum angle approx. 1/4 inch apart attached to the upper and lower tower plates that make contact when the lower tower plate is engaged by the minibot and pushed upward. Triggering is accomplished by completion of the circuit upon contact.

That’s also how I am understanding it, too.

EDIT:
I am a member of the Department of Redundancy Department

What it means is there is a little module in the tower that registers when the tower is held down for 1ms or longer, and the module tells the field management system every 5ms or less whether it has been activated and when. We still don’t know what the field management system does with that trigger though. It’s entirely possible that it requires a certain number of consecutive high signals from the module before counting the tower TRIGGERED.

5ms is a significant amount of time; does anyone know what happens to ties? Let’s hear it for a 60 point minibot race for one alliance!

I would guess that there is some kind of lockout system employed before the signal is sent to the FMS. Certainly if any trigger within 5ms caused a tie, I think we would have seen one by now.