Robot looses comms when hit/jolted
 

Our robot, for the last 2 or 3 years, seems to loose connection whenever its hit pretty hard by another robot. It was never that big of a deal, but today we got our bot driving and attempted the bump. It did make it over, but we lost communication when it got to the other side.

The only thing I can think of is something inside the cRIO could be damaged, seeing as this happens year after year. Or possibly the D-link, but I somewhat doubt that.

Anyone have this happen, or any ideas?

Re: Robot looses comms when hit/jolted
 

D-link power plug or Ethernet connection, maybe?

If you have the wrong size of power plug, or the connection is finicky, that could be the issue.

Re: Robot looses comms when hit/jolted
 

What you said is possible, however it's also possible that something is becoming disconnected when you bump things. I'd look into it further at your next meeting and get is figured out quick. If your robot looses communications every time it gets bumped, an accidental robot-to-robot collision will leave you helpless on the field. From me to you, fixing this problem should be a number 1 priority for your team now.

Re: Robot looses comms when hit/jolted
 

it was usually a harder hit, not every robot-robot hit. but going over the bump seems to trigger it. I'll check the dlink wires tomorrow, but it is the right type. Its the one that came with the dlink.

Re: Robot looses comms when hit/jolted
 

Well let's hope for your sake you never have to play defense. :p

Re: Robot looses comms when hit/jolted
 

Loose wire or possibly a cracked solder joint inside the AP.

Re: Robot looses comms when hit/jolted
 

Tripple check every electrical power connection. A loose connection could easily cause what you're describing, and if in the right place (like your battery terminals) could occur year after year. If you can wiggle the wires at all, tighten them down.

Re: Robot looses comms when hit/jolted
 

And check for little metal shavings in places they shouldn't be (like in between digital sidecar pins). When knocked around, they have a tendency to short things out and cause problems.

Re: Robot looses comms when hit/jolted
 

We had a similar issue back in 2010 whenever we would kick the ball (caused the entire bot to shake). Apparently the power connector to the cRio was lose. Check that out.

- Sunny G.

Re: Robot looses comms when hit/jolted
 

The wires going into the cRIO or the black connector? thanks!

Re: Robot looses comms when hit/jolted
 

Um, I believe it was the wires but I've slept since then.

- Sunny G.

Re: Robot looses comms when hit/jolted
 

You need to find out what exactly is making you lose connection.
If you regain connection after a few seconds, the problem probably lies in the cRIO. Make sure you have a solid connection to the PD board
If it takes some time, its the DAP. If its the DAP, make sure you have a solid connection to one of the dedicated power lines on the PD board.

Re: Robot looses comms when hit/jolted
 

Brandon,
There are a few things that could lead to your problem.
1. The power connector on the DAP has a spring clip for one side of the power input. If you tried to insert a large diameter plug at some point or if the connector was bumped in the past, this spring could be deformed enough to cause intermittent connection. The plug should be snug when inserted. Sometimes a small probe can be used to bend the spring back into position.
2. The power cable to the radio is not supported near the radio. My recommendation to all teams is to use a wire tie near the radio to secure the wire. During violent robot action, the wire and connector will not move.
3. Loose wires or stray strands of wire can easily move to an adjacent contact during violent robot action. Make sure the screws holding the wire are tight, tug test the wire and make sure there are no strands visible.
4. Some PD boards were manufactured with a small, surface mount capacitor near the edge of the board where the radio and crio power supplies are located. It is possible that this cap has come loose and is floating around in the vicinity of the radio power supply.
I am of course, expecting that you are using the 5 volt regulator, connected to the +12 volt radio connector on the PD and that all regulator connections are tight/soldered and insulated.

Re: Robot looses comms when hit/jolted
 

Thanks, Yes it is through the 5v supply through the 12v converter.

What exactly do you mean by the DAP? that black connector in the cRIO and distribution board?

Re: Robot looses comms when hit/jolted
 

The radio is a DAP 1522, sorry for the confusion.