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FRC2016-old/wpilib/cpp/current/include/Encoder.h

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2016-01-28 11:33:19 -05:00
/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008-2016. 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 "HAL/HAL.hpp"
#include "CounterBase.h"
#include "SensorBase.h"
#include "Counter.h"
#include "PIDSource.h"
#include "LiveWindow/LiveWindowSendable.h"
#include <memory>
class DigitalSource;
class DigitalGlitchFilter;
/**
* Class to read quad encoders.
* Quadrature encoders are devices that count shaft rotation and can sense
* direction. The output of
* the QuadEncoder class is an integer that can count either up or down, and can
* go negative for
* reverse direction counting. When creating QuadEncoders, a direction is
* supplied that changes the
* sense of the output to make code more readable if the encoder is mounted such
* that forward movement
* generates negative values. Quadrature encoders have two digital outputs, an A
* Channel and a B Channel
* that are out of phase with each other to allow the FPGA to do direction
* sensing.
*
* All encoders will immediately start counting - Reset() them if you need them
* to be zeroed before use.
*/
class Encoder : public SensorBase,
public CounterBase,
public PIDSource,
public LiveWindowSendable {
public:
enum IndexingType {
kResetWhileHigh,
kResetWhileLow,
kResetOnFallingEdge,
kResetOnRisingEdge
};
Encoder(uint32_t aChannel, uint32_t bChannel, bool reverseDirection = false,
EncodingType encodingType = k4X);
Encoder(std::shared_ptr<DigitalSource> aSource,
std::shared_ptr<DigitalSource> bSource,
bool reverseDirection = false, EncodingType encodingType = k4X);
Encoder(DigitalSource *aSource, DigitalSource *bSource,
bool reverseDirection = false, EncodingType encodingType = k4X);
Encoder(DigitalSource &aSource, DigitalSource &bSource,
bool reverseDirection = false, EncodingType encodingType = k4X);
virtual ~Encoder();
// CounterBase interface
int32_t Get() const override;
int32_t GetRaw() const;
int32_t GetEncodingScale() const;
void Reset() override;
double GetPeriod() const override;
void SetMaxPeriod(double maxPeriod) override;
bool GetStopped() const override;
bool GetDirection() const override;
double GetDistance() const;
double GetRate() const;
void SetMinRate(double minRate);
void SetDistancePerPulse(double distancePerPulse);
void SetReverseDirection(bool reverseDirection);
void SetSamplesToAverage(int samplesToAverage);
int GetSamplesToAverage() const;
double PIDGet() override;
void SetIndexSource(uint32_t channel, IndexingType type = kResetOnRisingEdge);
DEPRECATED("Use pass-by-reference instead.")
void SetIndexSource(DigitalSource *source,
IndexingType type = kResetOnRisingEdge);
void SetIndexSource(const DigitalSource &source,
IndexingType type = kResetOnRisingEdge);
void UpdateTable() override;
void StartLiveWindowMode() override;
void StopLiveWindowMode() override;
std::string GetSmartDashboardType() const override;
void InitTable(std::shared_ptr<ITable> subTable) override;
std::shared_ptr<ITable> GetTable() const override;
int32_t GetFPGAIndex() const { return m_index; }
private:
void InitEncoder(bool _reverseDirection, EncodingType encodingType);
double DecodingScaleFactor() const;
std::shared_ptr<DigitalSource> m_aSource; // the A phase of the quad encoder
std::shared_ptr<DigitalSource> m_bSource; // the B phase of the quad encoder
void *m_encoder = nullptr;
int32_t m_index = 0; // The encoder's FPGA index.
double m_distancePerPulse = 1.0; // distance of travel for each encoder tick
std::unique_ptr<Counter> m_counter =
nullptr; // Counter object for 1x and 2x encoding
EncodingType m_encodingType; // Encoding type
int32_t m_encodingScale; // 1x, 2x, or 4x, per the encodingType
std::shared_ptr<ITable> m_table;
friend class DigitalGlitchFilter;
};