REV Spark Max 6v output on 2/6 of our drivetrain motors

We’ve run into an issue with two of the REV Spark Maxes we’re using for our drivetrain (all brushless neos) that we weren’t previously having where the output voltage has dropped to 6v. I’ve been looking through our settings on the SPARK MAX client and have discovered that kInputMode is set to 2, while everything I can find online says it should only be possible for it to be set to 0 (pwm) or 1 (can). I can’t change this parameter. Other than that, all of our settings look fine to me. Does anyone know what might be causing this drop?

I don’t know what would cause this, but were the two putting out 6V in follower mode? If so, were they following the same controller?

Couple of questions for you:

  1. How are you measuring the 6V?

  2. What do you get when you read back the applied output from the getAppliedOutput() function, and the bus voltage using getBusVoltage()

The getAppliedOutput() command returns the actual duty cycle that is set to the power electronics of the device after and current limiting, ramping, limits, etc.

This needs to get updated in our doc, but this value is purely an indicator and is auto-set. The value ‘2’ means ‘USB’ and is new in firmware > v1.5.x

  1. Using an ammeter, we measured 12v going into the spark maxes from our PDP connections and then 6v coming out of the output wires on both spark maxes. Strangely, this issue came up on the robot but not on our test board when we plugged them into that instead to run tests.

  2. We got around 6-7 BusVoltage and -1 and 0 for AppliedOutput when they were plugged into the neos; when unplugged from the neos they returned roughly 11.6 BusVoltage and 0 AppliedOutput (reasonable given they weren’t plugged in).

As for the kInputMode piece, I figured that was a possibility but wanted to make sure. Thanks for the update!