VEXnet Keys Refuse to Connect to Each Other

Hello, we are having some difficulties with our team’s VEXnet keys connecting. We have done much research into our problem, but haven’t found a solution to our specific problem.

First of all, it should be known that these keys are the newest version, VEXnet 2.0. We received these keys before our competition last year, and have successfully used them to participate in the competition. This year however, we noticed that one of the two keys was making a rattling noise on the inside, and did not display any sign of being powered on. Promptly, we sent the one key back in to VEX (as it was still under warranty) and had it replaced.

Since we’ve received the new key, we have never once been able to connect it to the older one. It does, however, flash when plugged in. We are absolutely sure that the firmware is up to date on all of the components (both keys, the joystick, and the cortex). Also, we have went through the many step by step guides present on the vex wiki explaining how to connect the joystick to the cortex. I am absolutely positive that the controller and cortex are linked. The two connect with the USB connector cable, but refuse to acknowledge each other when the keys are connected.

this is what happens:
When turning the joystick and robot on the same time or with delay, the cortex flashes yellow in game and “vex-net”, and “robot” flashes green for about ten seconds, then everything stops flashing, and only “vex-net” double flashes red. The joystick turns solid green for “joystick” while “vex-net” flashes yellow. After about ten seconds, everything goes dark, and then “vex-net” double flashes red.

When holding the config button on both controller and cortex, while the keys are attached, all the lights flash green, then when we release the button, and “vex-net” holds solid green for about ten seconds, then “robot” flashes green,and “robot” flashes red. A few seconds afterwards, “vex-net” double flashes red. The joystick appears to do generally the same thing.

This is generally what happens. No matter what we try, there doesn’t seem to be connection established between the two Keys. Hopefully we can get a swift response. Thanks for your help. I tried to make our situation as easily understandable as possible.


Thanks for your detailed post.

Can you please attach a screenshot of your VEXnet Upgrade Utility and another screenshot of the VEXnet Key 2.0 Upgrade Utility?

Holding the config button will not help in this case, it might actually make things worst by setting your Microcontroller to bootload mode.


Hopefully I’ve successfully attached four images to this reply. The first two are of the keys and the second two images are of the cortex and joystick.

I apologize for the late response, seeing as we are an after school club, we haven’t had too mush time to be able to respond. We appreciate your reply, and hope we can get this problem resolved as soon as possible.
Key 1 Update Screenshot.jpg
Key 2 Update Screenshot.jpg
Cortex Update Screenshot.jpg
Joystick Update Screenshot.jpg


Based on your screenshots, I can tell (had to squint my eyes:)) you are running an outdated version of the VEXnet Upgrade Utility.

Please make sure you are running VEXnet Upgrade Utility 4.1.5, feel free to download it from here.



YAY! Thanks for the help, as soon as we updated the firmware, we were able to successfully connect the two keys.

Glad to hear I was able to help :slight_smile: