allwpilib/wpilibc/src/main/native/include/frc/DutyCycleEncoder.h

/*----------------------------------------------------------------------------*/
/* Copyright (c) 2019 FIRST. 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

#include <memory>

#include <hal/SimDevice.h>
#include <hal/Types.h>
#include <units/units.h>

#include "frc/AnalogTrigger.h"
#include "frc/Counter.h"
#include "frc/ErrorBase.h"
#include "frc/smartdashboard/Sendable.h"
#include "frc/smartdashboard/SendableHelper.h"

namespace frc {
class DutyCycle;
class DigitalSource;

/**
 * Class for supporting duty cycle/PWM encoders, such as the US Digital MA3 with
 * PWM Output, the CTRE Mag Encoder, the Rev Hex Encoder, and the AM Mag
 * Encoder.
 */
class DutyCycleEncoder : public ErrorBase,
                         public Sendable,
                         public SendableHelper<DutyCycleEncoder> {
 public:
  /**
   * Construct a new DutyCycleEncoder on a specific channel.
   *
   * @param channel the channel to attach to
   */
  explicit DutyCycleEncoder(int channel);

  /**
   * Construct a new DutyCycleEncoder attached to an existing DutyCycle object.
   *
   * @param dutyCycle the duty cycle to attach to
   */
  explicit DutyCycleEncoder(DutyCycle& dutyCycle);

  /**
   * Construct a new DutyCycleEncoder attached to an existing DutyCycle object.
   *
   * @param dutyCycle the duty cycle to attach to
   */
  explicit DutyCycleEncoder(DutyCycle* dutyCycle);

  /**
   * Construct a new DutyCycleEncoder attached to an existing DutyCycle object.
   *
   * @param dutyCycle the duty cycle to attach to
   */
  explicit DutyCycleEncoder(std::shared_ptr<DutyCycle> dutyCycle);

  /**
   * Construct a new DutyCycleEncoder attached to a DigitalSource object.
   *
   * @param source the digital source to attach to
   */
  explicit DutyCycleEncoder(DigitalSource& digitalSource);

  /**
   * Construct a new DutyCycleEncoder attached to a DigitalSource object.
   *
   * @param source the digital source to attach to
   */
  explicit DutyCycleEncoder(DigitalSource* digitalSource);

  /**
   * Construct a new DutyCycleEncoder attached to a DigitalSource object.
   *
   * @param source the digital source to attach to
   */
  explicit DutyCycleEncoder(std::shared_ptr<DigitalSource> digitalSource);

  ~DutyCycleEncoder() override = default;

  DutyCycleEncoder(DutyCycleEncoder&&) = default;
  DutyCycleEncoder& operator=(DutyCycleEncoder&&) = default;

  /**
   * Get the frequency in Hz of the duty cycle signal from the encoder.
   *
   * @return duty cycle frequency in Hz
   */
  int GetFrequency() const;

  /**
   * Get if the sensor is connected
   *
   * This uses the duty cycle frequency to determine if the sensor is connected.
   * By default, a value of 100 Hz is used as the threshold, and this value can
   * be changed with SetConnectedFrequencyThreshold.
   *
   * @return true if the sensor is connected
   */
  bool IsConnected() const;

  /**
   * Change the frequency threshold for detecting connection used by
   * IsConnected.
   *
   * @param frequency the minimum frequency in Hz.
   */
  void SetConnectedFrequencyThreshold(int frequency);

  /**
   * Reset the Encoder distance to zero.
   */
  void Reset();

  /**
   * Get the encoder value since the last reset.
   *
   * This is reported in rotations since the last reset.
   *
   * @return the encoder value in rotations
   */
  units::turn_t Get() const;

  /**
   * Set the distance per rotation of the encoder. This sets the multiplier used
   * to determine the distance driven based on the rotation value from the
   * encoder. Set this value based on the how far the mechanism travels in 1
   * rotation of the encoder, and factor in gearing reductions following the
   * encoder shaft. This distance can be in any units you like, linear or
   * angular.
   *
   * @param distancePerRotation the distance per rotation of the encoder
   */
  void SetDistancePerRotation(double distancePerRotation);

  /**
   * Get the distance per rotation for this encoder.
   *
   * @return The scale factor that will be used to convert rotation to useful
   * units.
   */
  double GetDistancePerRotation() const;

  /**
   * Get the distance the sensor has driven since the last reset as scaled by
   * the value from SetDistancePerRotation.
   *
   * @return The distance driven since the last reset
   */
  double GetDistance() const;

  void InitSendable(SendableBuilder& builder) override;

 private:
  void Init();

  std::shared_ptr<DutyCycle> m_dutyCycle;
  AnalogTrigger m_analogTrigger;
  Counter m_counter;
  int m_frequencyThreshold = 100;
  double m_positionOffset = 0;
  double m_distancePerRotation = 1.0;
  mutable units::turn_t m_lastPosition{0.0};

  hal::SimDevice m_simDevice;
  hal::SimDouble m_simPosition;
  hal::SimBoolean m_simIsConnected;
};
}  // namespace frc