wpilibc/shared/include/interfaces/Gyro.h

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2014-2017. All Rights Reserved.                        */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project.                                                               */
/*----------------------------------------------------------------------------*/

#pragma once

namespace frc {

/**
 * Interface for yaw rate gyros
 */
class Gyro {
 public:
  virtual ~Gyro() = default;

  /**
   * Calibrate the gyro by running for a number of samples and computing the
   * center value. Then use the center value as the Accumulator center value for
   * subsequent measurements. It's important to make sure that the robot is not
   * moving while the centering calculations are in progress, this is typically
   * done when the robot is first turned on while it's sitting at rest before
   * the competition starts.
   */
  virtual void Calibrate() = 0;

  /**
   * Reset the gyro. Resets the gyro to a heading of zero. This can be used if
   * there is significant drift in the gyro and it needs to be recalibrated
   * after it has been running.
   */
  virtual void Reset() = 0;

  /**
   * Return the actual angle in degrees that the robot is currently facing.
   *
   * The angle is based on the current accumulator value corrected by the
   * oversampling rate, the gyro type and the A/D calibration values. The angle
   * is continuous, that is it will continue from 360 to 361 degrees. This
   * allows algorithms that wouldn't want to see a discontinuity in the gyro
   * output as it sweeps past from 360 to 0 on the second time around.
   *
   * @return the current heading of the robot in degrees. This heading is based
   *         on integration of the returned rate from the gyro.
   */
  virtual double GetAngle() const = 0;

  /**
   * Return the rate of rotation of the gyro
   *
   * The rate is based on the most recent reading of the gyro analog value
   *
   * @return the current rate in degrees per second
   */
  virtual double GetRate() const = 0;
};

}  // namespace frc