Motors spin via “devices” interface direct control, but not using the controller

Weird problem here. I had wired up a Moby robot and things worked just fine, drive train and arms. I took the brain and wiring to use on another robot and brought things back. I updated the brain today to the latest OS before reconnecting things. I reconfigured the controls, the drivetrain works, but the left-hand motor does turn in one direction (in this case, down) when driven by the controller. If I use the “devices” interface on the V5 brain, I can get the motor to spin in both directions, no problems.

If I switch the port, I can get the motor to spin in both directions. So the motor is fine. I also changed the wires and used a different motor, but the problem persists. It could be port related, but it doesn’t make sense that I can get the motor to spin in both directions when using the “devices” interface.

While I can use a different port, I cannot setup the controller using regular controls for port 3. Is there anything else that I can do to troubleshoot this issue? I am going to eventually program the controller, but it bothers me that I had a working configuration that no longer works and basic troubleshooting shows that it should work.

Thoughts? Thanks in advance.

So to clarify, you are not using any programing and just using the internal Drive program ?

It almost sounds like there’s an issue with the three wire port, the motor on smart port 3 can be disabled by two limit switches placed into A and B of the three wire port, is anything connected to that ?


Yes! I did plug in a RangeFinder using ports A and B.

I configured the controller using VEXCodeV5 and everything worked! Port 3 works in both directions with the L1/L2 buttons. I came back to the forum to report my results and saw your reply.

I think you’re on to something. I’ll try unplugging that 3-wire sensor and retry manual configuration tomorrow. Where does one learn about these low level details?


Usually a good place to start would be here.
but I’m not sure we have an article about the default drive code.

You can look on the wiring screen for the drive program, that will give details on port usage, and the controls screen will give details on which controller buttons and joysticks will control which motors.


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