Encoder.h

/*----------------------------------------------------------------------------*/
/* Copyright (c) FIRST 2008. 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 $(WIND_BASE)/WPILib.  */
/*----------------------------------------------------------------------------*/

#ifndef QUAD_ENCODER_H_
#define QUAD_ENCODER_H_

#include "ChipObject.h"
#include "CounterBase.h"
#include "SensorBase.h"
#include "Counter.h"
#include "PIDSource.h"

class DigitalSource;

class Encoder: public SensorBase, public CounterBase, public PIDSource
{
public:
        typedef enum {kDistance, kRate} PIDSourceParameter;

        Encoder(UINT32 aChannel, UINT32 bChannel, bool reverseDirection=false, EncodingType encodingType = k4X);
        Encoder(UINT8 aModuleNumber, UINT32 aChannel, UINT8 bModuleNumber, UINT32 _bChannel, 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
        void Start();
        INT32 Get();
        INT32 GetRaw();
        void Reset();
        void Stop();
        double GetPeriod();
        void SetMaxPeriod(double maxPeriod);
        bool GetStopped();
        bool GetDirection();
        double GetDistance();
        double GetRate();
        void SetMinRate(double minRate);
        void SetDistancePerPulse(double distancePerPulse);
        void SetReverseDirection(bool reverseDirection);

        void SetPIDSourceParameter(PIDSourceParameter pidSource);
        double PIDGet();

private:
        void InitEncoder(bool _reverseDirection, EncodingType encodingType);
        double DecodingScaleFactor();

        DigitalSource *m_aSource;               // the A phase of the quad encoder
        DigitalSource *m_bSource;               // the B phase of the quad encoder
        bool m_allocatedASource;                // was the A source allocated locally?
        bool m_allocatedBSource;                // was the B source allocated locally?
        tEncoder* m_encoder;
        UINT8 m_index;
        double m_distancePerPulse;              // distance of travel for each encoder tick
        Counter *m_counter;                             // Counter object for 1x and 2x encoding
        EncodingType m_encodingType;    // Encoding type
        PIDSourceParameter m_pidSource;// Encoder parameter that sources a PID controller
};

#endif