Cortex Download Error


We were at a scrimmage in Auckland yesterday and half way throught the day, our laptop would not download the program to the cortex. We tried wireless and with the USB cable - we troubleshooted for a long time. Ports were right, vexnet was fine ect. We changed laptop and it worked once, and only once and then we got the same error as the other one - ‘Controller Could not be identified’

When we used the USB cable, it would not connect and lights would not go green as it normally would, the lights went red as if vexnet had just lost connection.

Any help would be greatly appreciated, as this was one of the factors that lost the finals for us and we dont want it to happen again

Were you able to reload the mastercode?

The mastercode could not be redownloaded, would resetting everything fix this?


Have you tried to download a program since the contest using the Vexnet to see if it was interference?

If this doesn’t work have you tried using the tethered link.

In EasyC 4 cortex it seems to dowload your program not mastercode you have to do the following.

You pull out the Vexnet keys from the cortex and the joystick then connect the joystick and cortex with usb lead.

Connect the joystick to the computer with the orange programming cable. Leave the joystick power off and turn on the cortex then try and download your program.

If you cannot re-download the mastercode, I would call Vex and see if they can help recover the unit.

we have fixed this issue - we do not know the cause yet. it started working after the competition although i dont think there was intereference because it did not download directly via usb.

When we were trying it at the competition we did not connect the USB the proper way for programming. (Note EasyC and RobotC do tether programming in different ways).

At some stage try out the instructions I posted earlier to make sure you can program via the USB cable.

This is just in case it happens at the next competition.
From posts on this forum it does appear that you can get interference using Vexnet.