WPILib integration

CoreRotem has no WPILib dependency at all, so the same code drives robot code, a bench tool and log replay. Rotem is the thin subclass that adds the WPILib-typed surface and nothing else.

import com.sapphify.frc.hardware.Rotem;

public class Drivetrain extends SubsystemBase {
  private final Rotem imu = new Rotem(0);          // can_s0
  // private final Rotem imu = new Rotem(0, SapphifyCanBus.systemCore(4));

  @Override
  public void periodic() {
    imu.refreshAlerts();
    poseEstimator.update(imu.getRotation2d(), modulePositions);
  }
}

Geometry

Method	Returns
getRotation2d()	heading, for a pose estimator
getRotation3d()	full orientation, built from the quaternion
getQuaternionWpi()	WPILib Quaternion

Counter-clockwise positive in NWU, matching WPILib. The coordinate-system documentation warns that some IMUs are clockwise-positive and must be inverted in user code; this one is not.

getRotation3d() is derived from the quaternion rather than from re-composed Euler angles, which lose information near gimbal lock.

Alerts

imu.refreshAlerts();   // call from periodic()

Every health flag is bound to one WPILib Alert at construction, with a severity that matches what the fault actually means:

Level	Flags
HIGH	device ID conflict, estimator numerical fault, firmware/library mismatch
MEDIUM	high vibration, magnetic disturbance, sensor saturation, FIFO overrun
LOW	temperature outside the calibrated range, calibration stale

The text is the same wording the core layer produces, which names the likely mechanical cause rather than the bit that was set. Alert has built-in change detection, so calling refreshAlerts() every loop is the intended usage rather than something to optimise around.

Dashboards

Rotem implements Sendable with the Gyro dashboard type, so it renders as a compass:

SmartDashboard.putData("IMU", imu);

Published properties: heading, yaw uncertainty, drift since zero, a healthy boolean, and the bus name. The class is also annotated @Logged, so Epilogue picks it up.

LiveWindow is gone

WPILib 2027 removed the LiveWindow and Shuffleboard classes entirely. Devices no longer auto-publish in what used to be Test mode — now called Utility mode — so put the putData call in your own code.

Simulation

var sim = imu.getSimState();
sim.setYaw(Units.degreesToRadians(90));
sim.setYawUncertainty(0.4);

Named and unit-matched to WPILib’s own OnboardIMUSim. The device appears in the simulation GUI under Other Devices as SAPPHIFY:ROTEM[0].

Usage reporting

The constructor calls HAL.reportUsage("ROTEM", deviceNumber, "SapphifyLib"), the string-based API that replaced the enum-based HAL.report in 2027. Nothing is required of you.