REV NEO Motors Dead In The Water

Greetings:
Our group has been struggling with these REV Neo Motors (REV-21-1650) and Spark Max Controller for a day or so.
We have two of them connected to our CAN bus. I have downloaded the latest SparkMax Client and both devices are showing connected on the Network tab and both devices have been updated to 1.5.1 firmware.

First a question: Should I be able to test (and by that, I mean get the motors to go) from the SparkMax Client? Or is this thing strictly for configuring and monitoring?

Next, our chief programmer has created a very simple program to run the motors in teli-op mode. The motors are completely still. Nothing happens.

One of the motors LED indicators is flash orange/magenta which apparently means “brushless encoder error”. We can’t find anything that explains what this is or how to correct it.
Any help would be appreciated.
Cheers,
Mark

Yes the client will allow you to run them, however they will not run while connected to a roboRIO (this is from a safety on the field perspective).

This means that the encoder signal is not being read. The NEO has a sensor cable, due to the way that brushless motors work, it is required that this cable is plugged into the SPARK MAX in order to operate. Can you verify that the encoder is plugged all the way into the SPARK MAX?

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Hi Will:
Thanks for the quick response.
We just checked the cables. They are pushed in as far as they can go.

As mentioned, we have two motors. So, disconnecting the CAN bus on the RoboRio and connecting just one of the motors through the USB port on my laptop, this motor is NOT the one that was reporting a “brushless encoder fault”. It is connected and flashing magenta, on and off, which means it is in “coast” with no signal.

I have gone to the “Run” tab and tried activating the “run” button. It says it is running. I have tried moving the “Setpoint” slider around. The Spark Max continues to flash magenta and the motors is quiet.

Also, under the “Run” tab there is a “Signals” menu where you can specify data that you would like to chart while running. I selected “Position” and when I go back to run mode and then manually turn the motor center axil with my hand, the chart does register a change in position.

Mark

Can you verify that the sensor drop-down on the UI is set to ‘Hall Effect’? You can also see this setting under the Advanced Tab ‘Basic’ drop down.

After removing it from the CAN chain can you also power cycle the controller that way it has never ‘seen’ the roboRIO.

Make sure that the Sparks are receiving power from the PDP while trying to run as well. When we were encountering this issue, we fixed it by restarting the laptop with the rev client, and it miraculously worked. I hope the same will hold true for you.

Hi Everybody:
During the course of the week, our chief programmer decided to re-program the SparkMax controllers, even though they were both reporting the latest firmware (1.5.1).

They suddenly started working.

This kind of thing makes me nervous. Anything that can suddenly start working for no known reason can suddenly stop working and for the same reason. Murphy’s Law clearly states that this must happen in the middle of a match.

Cheers,
Matk

We had similar errors to these last year, and shared your unease. However, once they were working, they remained functional for the rest of the season.
Your mileage may vary, though.

Does he know what he did to get them working? Last year we had some issues where the motor controller names were all the same on the CANbus which caused an issue similar to what you are describing. Once we sorted that out, things were fine. But if we added a new device to the network, we needed to name it correctly before it would work correctly. Because our programmer knew what had happened the first time, he was able to quickly solve it when it came up subsequent times.

I’m not saying that you had the same problem. But make sure the programmer knows what he did to actually fix whatever problem you did have. Otherwise, it may not be easy to solve if it crops up again.

Hi All:
One of the things that our programmer mentioned to me was that he got the motor working by manually twisting the axel - an artifact of brushless motors.

Sure enough, working with the SparkMax Client, we are finding if that you let the motor stop, it won’t go again until you jump start it manually. I’m guessing that this effect can be reduced by shrinking the dead-band down to nothing but I am also guessing that this will create problems of its own.

It also occurs to me, just now, that this could have been the problem all along. None of us thought to manually kick-start the motor on Saturday when we were struggling with it most of the morning.

Mark

Hi Mark,

This is not actually the designed behavior. The most common cause of this type of behavior is a connector on one of the three phases not fully making contact. For example, if you are using Anderson connectors for the motor phase wires, make sure that the contacts are fully seated forward and that each wire is crimped correctly. The high impedance path of one phase compared to the others can cause the type of behavior described.

-Will

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We will be checking that, forthwith.
Thanks, Will

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