Typical I2C Error Message

Greetings VEX-IQ support,

One of my 3 VEX-IQ controllers regularly experiences an I2C Error detected on the Motor Ports while in operation, requiring a reboot of the controller.

Attached is a image (albeit blurry) of the typical error message received, but in practice the motor port numbers that trigger the failure have varied (1-3, 4-6, 7-9, 10-12).

All of our controllers are currently running firmware version 1.07, but only one seems to consistently have this problem (during a scrimmage this past weekend, nearly every match experienced this failure).

Is there any diagnostic test that we can perform to confirm whether there is some internally issue with this controller?

Thanks in advance.

Curtis Sharif


The I2C error occurs when a motor or sensor becomes disconnected from the robot brain while a program is running.

The primary reason this occurs is that the cables connecting motors/sensors to the brain are not fully seated, so it may momentarily jostle loose when the program is running. They may look okay, but if they are not inserted until you hear a click they can come out when the robot is moving.

Another possible cause may be if the user attempt to pull out a cable without pressing down the latch on the plug, it is possible to damage the cable. The cable may work most of the time, but if you bend it just right the electrical connection will break.