PDF_control.h

#ifndef PID_v1_h
#define PID_v1_h
#define LIBRARY_VERSION    1.0.0

class PDF {

public:
    //Constants used in some of the functions below
#define AUTOMATIC    1
#define MANUAL    0
#define DIRECT  0
#define REVERSE  1

    //commonly used functions **************************************************************************
    PDF(double *, double *, double *,       // constructor.  links the PDF to the Input, Output, and
        double, double, int);               //   Setpoint.  Initial tuning parameters are also set here

    void SetMode(int Mode);                 // sets PDF to either Manual (0) or Auto (non-0)

    bool Compute();                         /* performs the PDF calculation.  it should be
                                               called every time loop() cycles. ON/OFF and
                                               calculation frequency can be set using SetMode
                                               SetSampleTime respectively
                                            */

    void SetOutputLimits(double, double);   /* clamps the output to a specific range. 0-255 by default, but
                                               it's likely the user will want to change this depending on
                                               the application
                                            */


    //available but not commonly used functions ********************************************************
    void SetTunings(double, double);       /* While most users will set the tunings once in the
                                              constructor, this function gives the user the option
                                              of changing tunings during runtime for Adaptive control
                                            */
    void SetControllerDirection(int);       /* Sets the Direction, or "Action" of the controller. DIRECT
                                               means the output will increase when error is positive. REVERSE
                                               means the opposite.  it's very unlikely that this will be needed
                                               once it is set in the constructor.
                                            */
    void SetSampleTime(int);                /* sets the frequency, in Milliseconds, with which
                                               the PDF calculation is performed.  default is 100
                                            */

    //Display functions ****************************************************************
    double GetKp();                         // These functions query the pid for interal values.
    double GetKi();                         /* they were created mainly for the pid front-end,
                                               where it's important to know what is actually
                                            */
    int GetMode();                          //  inside the PDF.
    int GetDirection();                     //

private:
    void Initialize();

    double dispKp;                          // we'll hold on to the tuning parameters in user-entered
    double dispKi;                          // format for display purposes

    double kp;                              // (P)roportional Tuning Parameter
    double ki;                              // (I)ntegral Tuning Parameter

    int controllerDirection;

    double *myInput;                        // Pointers to the Input, Output, and Setpoint variables
    double *myOutput;                       // This creates a hard link between the variables and the
    double *mySetpoint;                     /* PDF, freeing the user from having to constantly tell us
                                               what these values are.  with pointers we'll just know.
                                            */

    unsigned long lastTime;
    double ITerm, lastInput;

    unsigned long SampleTime;
    double outMin, outMax;
    bool inAuto;
};

#endif