Problem with losing communication while on the field.
 

We are team 3145 and we won the rookie all-star award after losing in the quaterfinals at the Portland regional.

During our quaterfinal matches, we lost communication twice. I was wondering if there was any way that this could happen due to a physical problem. We were thinking that the camera may have been hit and that the cable may have popped out. Could this cause us to lose comm?(We lost comm for two matches and it happened around halfway through during each).

Any help would be greatly appreciated. We are trying to figure this out before we get to Atlanta, but it is hard to do without a robot. Thanks for any info you can give.

Re: Problem with losing communication while on the field.
 

Check your cables, especially between the cRIO and the gaming adapter. That's the most likely culprit. It probably wouldn't be the camera cable (why would not being able to see where the target is shut down communications?).

Re: Problem with losing communication while on the field.
 

Your camera coming unplugged COULD cause you lose communication in a way. I cannot speak for LabView, but if you are using Java and your camera code isn't set up correctly, an attempt to read the data from a disconnected camera could cause an exception that might crash the cRio.

Re: Problem with losing communication while on the field.
 

If you're using the flat (Ribbon?) cable that came in the KOP, that might be your problem. When we were at Peachtree, and during practice, we had a couple of games where we lost communications for seemingly no reason. When we swapped the ribbon cable out to regular, bulky Ethernet cable, we had no problems. I don't know if it was absolute luck, or if there actually is a problem with those cables. Either way, it might be worth a shot!

Re: Problem with losing communication while on the field.
 

First two places I would look would be the ethernet cable from the cRio to the gaming adapter and the power cable from the power distribution board to the gaming adapter. Loose connections on either of those would be a likely cause.

Do you regain communications? IF so, hoe long does it take? It could be the cRio rebooting after a power fail or other condition.

Re: Problem with losing communication while on the field.
 

Look for intermittent shorts between the robot chassis and the cRIO or camera chassis. Use a multimeter to determine whether your chassis is electrically connected to any of the robot's wiring.

If the cRIO or camera momentarily touch a chassis that is connected to a voltage other than ground, the power supplies will probably reset.

Russ

Re: Problem with losing communication while on the field.
 

Invest in a HOT GLUE gun, and hot glue the Ethernet connectors into the radio and crio. Also hot glue the power connector in the radio. For that matter hot glue EVERYTHING, the PWM connectors into the victors, CAT5 cables into camera, etc. Hot glue all the way around each connector. Pot-it-in like the military people do it.

Re: Problem with losing communication while on the field.
 

We have had problems like this at both regionals we have attended so far. We tried tons of troubleshooting methods. From having our wiring looked at by an electrical engineer, to switching from 2CAN to CAN, to fully switching our code over from Jave to C++, we frequently would just lose communication mid-match. We even considered replacing our C-Rio at the regional..

As it turns out, we grabbed a spare radio from the parts desk, had it programmed, and we ran fine for the rest of the day. The issue is, there isn't a way to detect a faulty radio assuming it is getting power, not that I'm aware of.


It was extremely frustrating because we knew it wasn't our code or our hardware. We were assuming it was some error with the FMS. We never fixed the problem at the DC regional, and were scrambling to find the problem with the condensed schedule at Pittsburgh.

Re: Problem with losing communication while on the field.
 

It could have also been a problem with your classmate. If you allow it to go into hibernate after turning it on, it will have problems with connecting. We had problems on the first three matches at our regionals because of such a problem (along with our the fact that our during our first match our mechanics forgot to reconnect the speed controllers.)

Re: Problem with losing communication while on the field.
 

Oh, this is a GOOD point. This happened to us once and also when you close the lid on the classmate too. I know...ask my drive team :-) I closed the lid on them during drive practice one day, to ween them away from the camera feedback. I said "You just lost the live feedback from the camera during the match, so keep on driving..." Right when I closed the lid, the whole robot died...guess you had to be there. It was a funny moment.... Moral of the story, don't close your Classmate lid in the middle of a match, instead put a piece of paper over the screen to cover up the video feed...

Re: Problem with losing communication while on the field.
 

Check the game adapter power cable. We had problems with communications on the field too. Come to find out the the power cable hole was too big for the pin and it would move and reset the game adapter. So find a cable that is closer to the pin size.

Re: Problem with losing communication while on the field.
 

Do you redo the hot glue each time you need to tether the robot?

At Phoenix, I saw several bad Ethernet cables, several bad bridges, and several bad electrical connections. We also had one team whose joysticks weren't recognized after restarting the classmate.

Re: Problem with losing communication while on the field.
 

I know this isn't really part of thread, but why is it bad to have video feedback? We worked hard to get ours working well, now I'm wondering if there is a consequence we haven't thought of. Are the drivers staring at it too much?

Re: Problem with losing communication while on the field.
 

Please don't do this. You will regret it as soon as you need to power up your robot in the pit.

Re: Problem with losing communication while on the field.
 

It's easier to just minimize or close the Dashboard window.