Falcon Strange Blinking pattern - HELP

We (5847) have a problem with our code/falcons. We are using LabView and our coding mentor is a professional LV programmer with lots of experience with FRC.

We have 2 falcons running our elevator. We intermittently have this problem where the motor LED’s are blinking in an unusual pattern. One of the lights blinks in the regular 1/2 second pattern. But the other one blinks in a non-patterned format. I call it twitchy blinking.


When the lights are blinking this way, the elevator motor becomes very jumpy in its operation. When the lights start doing that, the same twitchy blinking occurs on ALL the falcons throughout the robot. We have tried power-cycling everything. We have tried checking out can bus usage (we do have about 16 or 17 devices on the can bus), and the bus usage on the drivers station seems to be hovering in the 40-60% number during operation. We have a long can run to the turret and we tried it with and without a 150 ohm resistor. We thought we had identified a Motor close Block in LV as maybe the culprit, but we no longer are convinced of that. We are using the new REV PDH but the old PCM. We have tried removing the PCM from the system and sometimes the problem exists, sometimes not. When the lights aren’t twitch, the motor will work just fine with normal red/green lights as it operates, other times it has this twitchy behavior. We are pulling our hair out trying to run this down. ANY Help or ideas would be greatly appreciated.

Mark Hampton
lead mentor, 5847

Mark Hampton
NBCT Certified Teacher
FIRST Robotics Mentor

Are you getting error messages on your driver station?

I would start by running no code on the robot and instead actuating a motor with phoenix tuner and seeing if the behavior is replicated, this should hopefully let you narrow the behavior down to either hardware or software.

This looks like the same problem we had, where any of the CTRE speed controllers would disable or not enable at all. See this thread:

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