We need help with CAN spark max motors

Here is the problem: Our CAN spark max’s were originally communicating with motors fine, but they stopped communicating. When we did a test run with the robot driving it around, the motors worked completely fine. However, when we went to go test motors individually, using the REV Spark Hardware Client, all of our motor controllers stopped communicating with the motors. We can see all of the Spark Max’s on the hardware client and can blink them as well to identify them. However, when we try to run them using the software, it shows that the motors are running, but in reality, they are not. Do you think this can be an issue with the wiring or hardware on the robot?

Team 5549

A Spark Max will not respond to the Rev Hardware Client if it has detected the roboRIO at any time while it’s been powered (to prevent control coming from two places at once).

If you want to use the Rev Hardware Client to drive a motor, then you will need to disconnect the Spark MAX (or the whole CAN chain) from the roboRIO before powering it up.

Thank you for your response, however we have run the motors connected to the SparkMax with the RoboRio on before. I’m not sure how it would be a problem now since it has worked before with RoboRio connected.


I am not sure what the situation was before when you ran the motors, but as Mark said they will not run with the rev hardware client if the are getting signals from the Rio. Disconnect them from can or power down the Rio so they don’t receive communication on the can bus.

I don’t have access to our 'bot to confirm this, but I think it may be enabling that poisons the SPARK MAX to not allow control via the client. This is a safety feature, so the word poison shouldn’t be taken as a criticism of any sort; it was just the word that fit here.

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