VEX IQ Drivetrain Troubleshooting

Need some support with an odd problem. We are using a 2nd gen kit, our drive train is connected to ports 1 and 6, however our controller is not working as expected no matter how it is configured and coded. The left motor is moving forward and backward but the right is working in reverse so when the joystick is pushed forward it is moving backward.
One fix we have found is using one side to control <^>V but this has them using left right as forward/back and forward/back control for turning.

Can you post images of your code and the port setup for the motors (e.g. reversing)?

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If your team is using tank control, it is often helpful to lift the drivebase off the ground and run one joystick at once. I think I’ve seen teams that wired left and right backwards having trouble figuring it out until they ran it independently.

The other idea for drivebase debugging (especially for holonomic drive), is to have the kids put the robot on the ground, push it a direction, and see how the motors turn. This is the best way to learn to program an X drive. With a tank drive, they might notice that the left motors turn in the + direction (marked on back of the motor) when the drive goes forward, while the right motors turn “backwards”. When you program the drivebase, one side’s motors must be reversed. I believe the built in code does this automatically, but custom code would need this done. Hence, there’s a setting in the motor setup to handle this. If they use the built in drivebase setup, less sure as we don’t have teams this year.

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So in the default drivetrain setup- and do not have the option to reverse a motor. When we set up the motors individually we can reverse but it does not give us the joystick as an option for controller configuration.

Presumably you’re either direct-driving or have the same gear setup on both sides? The only other thing that would jump out at me with the drivetrain would be if you had a different gearing setup on one side compared to the other (or you had a motor connected to a different gear in the geartrain by accident).

I understand what you are saying, I have had this issue multiple times. If you can move your motor on the robot, then swap the side it is mounted, if you cannot, you will have to code your own drive code, the perks of this are you can reduce controller drift by adding a deadzone, and can have more control. I can walk you through this If you wish.

Feel Free to message me or reply here with any questions!
(I do have classes so my responses might be a bit delayed)

VIQC Team 21037A Head Programmer and Captain

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