Debugging the Swerve Drive System

How to bring up a swerve drivetrain on a real robot and check that every motor is wired and configured correctly. Use this when a robot is new, has been rebuilt, or is driving strangely.

WARNING

Put the robot on blocks before any of this, with the wheels free and not touching anything. A miswired swerve module can drive the robot in an unexpected direction at full power.

Set up before testing

1. Get an Xbox controller for the robot.
2. Update the main branch in Git or GitHub Desktop.
3. Open the current season's robot repository (for example TeamXbot2026), then run the Build Robot configuration.
4. Put the robot you want to test on blocks. Make sure the wheels are free and not touching anything.
5. Turn the robot on, then connect to it -- WiFi if it works, otherwise a cable.
6. Open FRC Driver Station.
7. Run the Build & Deploy Robot configuration while connected to the robot, then connect the controller to your computer.
8. Carefully enable the robot through FRC Driver Station.
9. Open Elastic (WPILib). Choose File, then open layout, find the season repo's elasticLayout file, and open it. Halve all the speed limits and set the correct Electrical Contract.

Test individual motors

1. Press up on the D-Pad to put the robot into motor testing mode. Press right on the D-Pad to switch between individual motors.
2. Test each motor:
   • Push the left joystick slowly upwards. If that motor's wheel moves in the intended direction, the drive motor works.
   • Push the right joystick slowly to the right. If the wheel steers in the intended direction, the steering motor works.
3. Repeat for every motor. You only need the up-arrow step once.

If a motor moves the wrong way or not at all, fix its configuration in the code before continuing.

Back to normal driving

1. Press down on the D-Pad to return the robot to normal drive mode.
2. Push the left joystick. All motors should now move together, in the direction you expect.
3. If the motors jitter, they may be inverted in the code. Correct the inversion in the Electrical Contract.

Related

• Robot Coordinate Conventions -- which way is positive, for both the robot and the field
• Swerve Drive -- how the swerve code is structured
• Elastic -- the dashboard used above