Motor Controllers

YAGSL supports most common FRC motor controllers (except Venom's) and while we recommend using a brushless motor with an integrated encoder if at all possible we support brushed motors with external quadrature encoders as well ONLY with SparkMAX's.

The integrated encoder value will show up in shuffleboard under Module[...] Raw Motor Encoder as directly outputting the encoder value from the motor.

Motor Checklist

• All motors spin counterclockwise positive, if not document inversions required to achieve that.

• PID is tuned to the best of your abilities.

• Motor is updated to the latest firmware.

• Motor has unique CAN ID.

• CAN ID given corresponds to the one in the JSON module.

• Wheels are aligned forwards with all bevels facing the same way.

Swerve Motor Wrapper

YAGSL created wrappers over all supported Motor Controllers to uniformly fetch and set data that is needed for a Swerve Drive to operate. This wrapper is called SwerveMotor. All SwerveMotor's can be fetched via the SwerveModule configuration object SwerveModuleConfiguration motor definitions angleMotor and driveMotor. The SwerveModule is able to be fetched by SwerveDrive.getModules() easily.

 /**
   * Initialize {@link SwerveDrive} with the directory provided.
   *
   * @param directory Directory of swerve drive config files.
   */
  public SwerveSubsystem(File directory)
  {
    // Angle conversion factor is 360 / (GEAR RATIO * ENCODER RESOLUTION)
    //  In this case the gear ratio is 12.8 motor revolutions per wheel rotation.
    //  The encoder resolution per motor revolution is 1 per motor revolution.
    double angleConversionFactor = SwerveMath.calculateDegreesPerSteeringRotation(12.8, 1);
    // Motor conversion factor is (PI * WHEEL DIAMETER IN METERS) / (GEAR RATIO * ENCODER RESOLUTION).
    //  In this case the wheel diameter is 4 inches, which must be converted to meters to get meters/second.
    //  The gear ratio is 6.75 motor revolutions per wheel rotation.
    //  The encoder resolution per motor revolution is 1 per motor revolution.
    double driveConversionFactor = SwerveMath.calculateMetersPerRotation(Units.inchesToMeters(4), 6.75, 1);

    // Configure the Telemetry before creating the SwerveDrive to avoid unnecessary objects being created.
    SwerveDriveTelemetry.verbosity = TelemetryVerbosity.HIGH;
    try
    {
      swerveDrive = new SwerveParser(directory).createSwerveDrive(maximumSpeed, angleConversionFactor, driveConversionFactor);
    } catch (Exception e)
    {
      throw new RuntimeException(e);
    }
    swerveDrive.setHeadingCorrection(false); // Heading correction should only be used while controlling the robot via angle.

    for(SwerveModule m : swerveDrive.getModules())
    {
      System.out.println("Module Name: "+m.configuration.name);
      CANSparkMax steeringMotor = (CANSparkMax)m.configuration.angleMotor.getMotor();
      CANSparkMax driveMotor = (CANSparkMax)m.configuration.driveMotor.getMotor();
    }
  }

Motor Controller Configuration

Inside any module JSON such as frontleft.json,frontright.json,backleft.json,backright.json this is what you would see to configure a motor controller.

{
  "drive": {
    "type": "sparkmax",
    "id": 5,
    "canbus": null
  },
  "angle": {
    "type": "sparkmax",
    "id": 6,
    "canbus": null
  },
  "encoder": {
    "type": "cancoder",
    "id": 11,
    "canbus": null
  },
  "inverted": {
    "drive": false,
    "angle": false
  },
  "absoluteEncoderOffset": -18.281,
  "location": {
    "front": -12,
    "left": -12
  }
}

Possible Motor Controller Types

Device	type
SparkMAX	sparkmax
SparkFlex	sparkflex
TalonFX	talonfx
TalonSRX	talonsrx
SparkMAX Brushed	sparkmax_brushed

At this time I do not provide documentation on brushed motor utilization, like sparkmax_brushed and talonsrx.