Cortex Reset

At our state competition we once again expierenced the reseting of the cortex. When we hit the wall barley, it will reset the autonomous program over and over. Using ROBOTC the backup battery only worked half the time in stopping it.

Our batteries are firm and we can move the connector all around and doesn’t effect the cortex

In a previous post, jpearman had this to say about your issue:


I think when he said he needs a video of your LEDs, he meant he needs to see your joystick and Cortex lights in order to make a call on what the problem might be. Your other video just showed the clever way you stow your battery.

Personally, it sounds like static to me, too. Are you using integrated motor encoders? There might be a way to add some code to RobotC so at least the program can skip over the autonomous when the Cortex resets. Not sure, though.

Nope. It starts over. Possibly manipulating the file system could theoretically do it. But that seems painful. That is the only persistence option I can think of to let you know run to run.

Actually you can. There’s a flag that indicated whether reset was caused by the watchdog or by power on.

link to old example.
ROBOTC V3.59 Beta watchdog timer

There are also mechanical based options you can use. For example, if you have some mechanism that releases at the start of auto, attach a limit switch. At the beginning of your program check if the system has already been released, and if it has, don’t run anything.

Is it also possible that the VEXnet key very briefly lost contact with the USB plug from bumping into the wall? Have you taped in the key?

By the time i get my phone out to record it starts up again, it will restart the program in a matter of 2 seconds and somtimes it restarts, some times it just blinks red in the middle one and we have to turn everything back on and off again.

It does it with the usb wire and the vexnets - both.

we don’t use motor encoders

When it hits the corner of the robot to the wall, it resets like think as if you are pairing your devices together. The light set is the same as when you turn both on and pair with vexnets.

We haven’t taped them because we can ram into the wall and it resets and i barley touch the wall at like 30% really soft touch power and it still did it.

We have seen this with nicked wires.

Your exposed wire could be touching the robot and disrupting the signal on a non-IME wire. Not sure if it has as dire consequences as the IME static discharge.

Check the wires around corners and crimped points. Channels for the corners are legal now to help prevent this.

Like diagnosing a car with electrical problems this can be very time consuming and very frustrating. Needles and haystacks come to mind… But you might get lucky.

That’s true if it was possible that when the robot and the metal on the field touch, creates a connection between the two causing the cortex to receice a shock that resets the cortex… maybe

I will check for cut wires