Has anyone else experienced this? I have checked and made sure that all of the wiring is good on our robot, yet every time we ramp over a defense (i.e. rock wall) and slam down, our robot drops connection. All wires are secured and locked in to their ports (power, ethernet, pwm, etc.)
Could this be a result of shock causing the radio/roboRIO to reboot?
If you have had this problem, please share your solutions.
Check your main breaker to make sure it isn’t bad. There are a couple each year… With the bad ones, you can tell by lightly tapping on the red button while watching the LED’s on the robot - with a bad one they’ll flicker.
My team’s main breaker was bad, but in a different way- the lever inside that lets you turn it on was broken. Brand new, out of the box for may be a day. It was the only one I’ve seen broken like that. Fortunately, we had a few spares sitting around 
Double check that the fuses on the PDP are full inserted. They can look good but are actually far from fully mating. Are you getting just a very short (one or two seconds) drop or are you getting a radio reboot?
We had this happen to us a few times Saturday during our first test drives over the defenses. We are going to do trouble-shooting this evening. I also saw another thread that described a similar (possibly the same) problem.
It seems like a radio reboot, I’m just speaking from what the students have told me. It goes down for a good 30 secs.
I’ll check the main breaker as well. Thanks guys.
What do you learn from the driver station logs? http://wpilib.screenstepslive.com/s/4485/m/24193/l/144980-driver-station-log-file-viewer
We have been experiencing this exact same issue. When we go over the defences we drop connection. We have isolated the issue to the roborio. We’re still trying to figure out how to fix it. We’re currently trying to add suspension to our roborio and hoping that fixes it.
What power plug in to the radio are you using? Wiggle it. If you do not get stable power, that might be your problem.
I haven’t personally seen any of the logs, but I can check when I get to the meeting this afternoon. Usually there aren’t any errors from what I’ve seen, but I could be wrong.
We had this happen last night too. The power connector for the radio came unplugged while going over the rock wall.
We had very similar comms issues, which were solved by checking the fuses.
Those minifuses are very good at pretending to be fully seated when they really aren’t. My advice to teams for getting them in all the way:
As a rule of thumb (!), if you can pull them out with your fingers they aren’t pushed in hard enough.
If your using a two speed transmission check to make sure your in low.
Would you be able to post a video of how hard you guys breach?
This leads to an interesting question: with all of the rough defenses, will bots have increasing comm problems during the tournaments as the systems get shaken up?
I would not be surprised. This game will probably put more stress on robots than Aerial Assault due to the fact that you’re pretty much required to go over the defenses.
BTW, we haven’t been able to run the robot tonight. Still wiring up sensors and putting some final touches on before we get the code debugged and start practicing.
We had this problem as well, and we noticed that it was because the ethernet port in the RoboRio was coming loose. We fixed it by using the socket saver from the KOP and ziptieing it to the RoboRio so it had a firm connection even when it was being pulled on.
Can someone explain why this would be a problem? Currently, we are able to go over the B+D defenses by starting low and shifting to high to gain momentum which gets us over the defenses. If this is actually a problem, we might have some serious problems.
If you are going over the defenses in a high speed gear, you may not have enough torque to the wheels / belts to actually climb. You can stall the motors, potentially causing the thermal breakers to break, and possibly causing the system voltage to drop below the reset point.
Use the recording capabilities and look at total current draw and voltage drop as you drive over defenses and around the field.
You can also use JVNs drive design tools to look at your drive design and the estimated loads.
My response is all based on a hypothetical situation, not one we actually experienced this season … 
We had a similar problem with the radio dropping out. I believe all we did to fix it was secure all the connections and tape the power plug to the radio.