Rah Cha Cha Rukus (Rochester, NY) Observations

Good Morning all-

We had a scrimmage last night hosted by Penfield Robotics Team. While there a number of issues became apparent with the OI and RC capabilities of the robot- so much so that I am writing this post to urge you to test them before you ship.

  1. When unplugging the OI from the Robot tether the channel would reset to 40.
  2. When unplugging the OI from the Robot Tether the OI would occasionally reboot, and then reset to channel 40.
  3. The ‘no data’ red light would come up at least 15% of the match, even when everything was running correctly. Commands would lag and the system had horrible response time- you could just sit there and watch when all the Victors lost signal as the match would progress.
  4. The default wheels and the carpet at the site generated tremendous amounts of static electricity- something new this year (I’m assuming they didn’t build a totally new field). PLEASE BE CAREFUL when touching your electronic components.
  5. As many people have said the default transmissions are not up to the level of quality that was expected. I’ll supply a photo that looks like a pile of grease on a steel plate, when instead it’s simply the faux-steel that has been mushroomed when the tranny sheared. Pathetic.
  6. Not a single team I watched had an autonomous mode.

X-Cats 191 had a defensive autonomous mode that went to the other side of the field and drove around.

That would could constitute ramming another robot and could be assessed 10 point penalty… I didn’t get to see that operate tho.


The 1511 girls thought it was “cute”.:smiley:

the second link is for the 2006 game. would those rulings still apply. because if they did they contradict the ruling from the first. if you jit a robot, which is aiming to score an inner tube, then according to the second link, no penalty

No. Rulings from past games do not apply to this year.

1/2) With a real competition port interface, the OI will not have issues with channels/team numbers. Since IFI will not release the interface spec, and the few people who figured out the spec will not speak of it because of “GP”, we were unable to provide competition control of the OI.
Last year, however, we did not see the OI channel # resetting at all when tethering/untethering.

  1. The radio modem issue is becoming more apparent as teams have had the opportunity to drive their robots. There are numerous threads on failures and successes with the modems on the Control System board. The regionals that occur in the first week will really show us how bad it is going to get.

  2. The carpet is from last year’s competition, and the carpet + incredibly dry air definitely = static.

  3. New transmission carrier plates will be available for teams at their first regional. I suspect the first night in the pits, and the NASA machine shop, will be VERY busy with these replacements.

  4. Defensive autonomous modes get called for ramming depending on speed and the ref’s. Driving across the field to interfere with your opponent is part of the game, as long as it does not do so in a hazardous or illegal method (such as hitting above the bumper line).

I’m not surprised about the lack of auto modes, most teams spent their time off the field getting their bots to work better/at all. The point of the event was to allow teams to try their bot out, drive against some opponents, work with other teams, and provide a nice spot to get your robot shipped out.

We also got the chance to get one of our neighbor team’s bots up from a very unhappy state in the afternoon, to a driveable/workable state by the end of the evening. Regardless of all the rest of the problems during the day, helping a fellow FIRST team get up and working so they can compete at Finger Lakes made the day worth it.



Please don’t mis-understand- the event was very positive and we’re DEFINITELY grateful! In fact, it highlighted several problems with our actuator that were fixed before ship and will have to be examined in the pits (I also got to add limit switches to prevent further gear shears).

What’s GP ? Why is it a limitation on the OI interface?

“GP” is Gracious Professionalism. It’s an important concept in the FIRST culture. Consider it a combination of Google’s “Don’t be evil”, Scouting’s “Do a good turn daily”, and the old Army “Be all you can be” slogan.

The reason it applies here is that IFI has asked that the radio modem control protocol remain a secret. Someone with sufficient skill can figure it out (and some have done so), but having those skills often implies a level of maturity and wisdom that keeps one from using the knowledge for ill purposes. If the protocol were published openly, however, any random script kiddie would be able to hack together something to disrupt a FRC competition.

I think more what we’re looking for is how to use the competition port to automagically set radio channel numbers, not how their radio modem protocol works. As it stands right now, anyone with a moderately powerful transmitter in the 900MHz band is going to cause some havoc if they get near the field. For a script kiddie to use the competition port information to cause havoc, they will still need to pick up an RC or OI, the radio modem, and a battery, package it, and carry it around. Given the cost of IFI parts, if someone really wanted to disrupt a FIRST field, it’d be cheaper and easier to just make or buy a transmitter in the same band.

For pre-ship and/or off-season events where you don’t have access to an official FIRST field, we run the risk of untethered robots in the pits interfering with robots competing in matches. It’s not just a risk, it happened! This is the same risk that official competitions would have if we had access to the competition port, so I can understand why IFI would be reluctant to release it. The main difference is that the interface to the competition port is not going to be as simple as building yourself an autonomous/disable switch box, so it’s highly unlikely teams will accidentally leave them connected to their competition port in the pits.

For the Rochester pre-ship meet next year, I’ll spend the time needed to get the protocol extracted and work with our Labview Guru to integrate it with his field control system. Hopefully that will resolve the radio channel issues we have to fight with during these unofficial events.


You forgot MAK’s fan freindly Auto Mode.

See, it’s harmless.

any other videos that arn’t that site ed? I would love to see them.

If our team was 100% ready we would have loved to come,

I’m going to stick with the response we use in business:

Security through Obscurity isn’t Security- it’s wishful thinking.

As you’ve pointed out, anyone with the right equipment could disrupt the competition- but anyone at the competition could RF in on them too.

I believe that that is a very small problem and one that warrants concerned indifference- Our team wasted nearly 2 hours trying to get the robots to work while not understanding why the system was failing (receiving other robots interference) whereas if the standards had been opened and they were able to implement the protocols correctly we would not have had those issues.

I hope.

3 more days till competition…