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#ifndef PID_h
#define PID_h
#include "chtypes.h"
//Constants used in some of the functions below
#define PID_AUTOMATIC 1
#define PID_MANUAL 0
#define PID_DIRECT 0
#define PID_REVERSE 1
#define PID_ON_M 0
#define PID_ON_E 1
typedef struct {
float kp; // * (P)roportional Tuning Parameter
float ki; // * (I)ntegral Tuning Parameter
float kd; // * (D)erivative Tuning Parameter
float dispKp; // * we'll hold on to the tuning parameters in user-entered
float dispKi; // format for display purposes
float dispKd; //
int direction;
int pOn;
float *input; // * Pointers to the Input, Output, and Setpoint variables
float *output; // This creates a hard link between the variables and the
float *setPoint; // PID, freeing the user from having to constantly tell us
// what these values are. with pointers we'll just know.
unsigned long lastTime;
float outputSum;
float lastInput;
unsigned long sampleTime;
float outMin;
float outMax;
bool inAuto;
bool pOnE;
} pidc_t;
//commonly used functions **************************************************************************
void pid_create(pidc_t* p, float* Input, float* Output, float* Setpoint, // * constructor. links the PID to the Input, Output, and
float Kp, float Ki, float Kd, int POn, int Direction); // Setpoint. Initial tuning parameters are also set here.
// (overload for specifying proportional mode)
void pid_setMode(pidc_t* p, int mode); // * sets PID to either Manual (0) or Auto (non-0)
bool pid_compute(pidc_t* p); // * performs the PID calculation. it should be
// called every time loop() cycles. ON/OFF and
// calculation frequency can be set using SetMode
// SetsampleTime respectively
void pid_setOutputLimits(pidc_t* p, float Min, float Max); // * 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 pid_setTunings(pidc_t* p, float Kp, float Ki, float Kd, int POn); // * 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 pid_setDirection(pidc_t* p, int Direction); // * 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 pid_setSampleTime(pidc_t* p, int NewSampleTime); // * sets the frequency, in Milliseconds, with which
// the PID calculation is performed. default is 100
void pid_initialize(pidc_t* p);
#endif
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