Connection Problems

Our VexNet Isn’t connecting. In matches, we will stop working for long periods of time. Any solutions?

Have you run through this flowchart (pg. 11 / section 8)? You may also want to take a look at the light pattern chart.

Also, make sure you have a backup battery plugged in. Make sure your vexNet key on your robot is not touching any metal in the surrounding 2" from the top and sides of the vexNet key.

We have the backup battery plugged in and everything seems to be in order. We have run it by all our best programmers to see if it’s a programming issue. We can’t fix it. Is it time to get new keys?

I would say it just might be time. Definitely if you can remember them being dropped/abused/hit/etc. The keys are fragile compared to the rest of VEX’s products, so they sometimes end up taking the same abuse, which can cause the keys to break.

However, some things I would double check: firmware, use the USB A-A to check communication between joystick and cortex. My guess is that you’ve already done these. Before purchasing new keys, (if possible) try the pairing different keys with the same joystick/cortex and/or using the same keys with different joysticks and cortexes. My point is: figure out which key (if not both) is broken before buying new ones. Plus, it may be that the joystick or cortex USB connection has gotten too insecure and “wiggles.” I’ve seen that happen if you jam the key in during competition once too many times.

try it with the orange cable. if it works and does not work with vexnet, then it is the keys. If it still does not work with the orange cable, then you need to look for the problem somewhere else.

a couple things to look out for when testing the keys:

-make sure that the cortex, controller, and keys are not getting warm. if they are, give everything a break and once cool try connecting again.

-make sure all battery power in controller and cortex are at full.

-check that the metal prongs in the keys are making contact with those in the cortex and controller. I have found when i hold keys so that the metal ends are being squeezed together it can fix some connection problems.

-disconnect the controller from the computer and competition controller if you are using those things.

i have not seen/written any code that could cause the robot to lose connection. i don’t think it would be a code problem. if that is a concern, upload a piece of really simple code. something that prints a line of text for example.

could you report what the lights on the controller and cortex do when it diconnects? it could help to diagnose the problem.

hope this helps

If it just blinks red about once a second then its broken, you need a new one. It’s happened to us a few times after we dropped the remote about 8-9 times with the key in it. Remote is always fine, just replace the vexnet key.

Thanks for the help!