// -----------------------------------------------------------------------------
/// @file  PID.h
/// @brief File description
// -----------------------------------------------------------------------------
//  Micro-Key bv
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//  The Netherlands
//  Tel: +31 594 503020
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//  Web: www.microkey.nl
// -----------------------------------------------------------------------------
/// $Revision$
/// $Author$
/// $Date$
//  (c) 2015 Micro-Key bv
// -----------------------------------------------------------------------------

/// @defgroup {group_name} {group_description}
/// Description

/// @file PID.h
/// @ingroup {group_name}

#ifndef INC_PID_H_
#define INC_PID_H_


// -----------------------------------------------------------------------------
// Include files 
// -----------------------------------------------------------------------------

#include <stdbool.h>

#include "stm32f10x.h"

// -----------------------------------------------------------------------------
// Constant and macro definitions 
// -----------------------------------------------------------------------------

#define PID_FIXED_POINT_FACTOR         (10000)

// -----------------------------------------------------------------------------
// Type definitions. 
// -----------------------------------------------------------------------------

struct Pid
{
   int iTerm;
   int Kp;                             // proportional constant
   int Ki;                             // integration constant
   int Kd;                             // differential constant
   int input_d1;                       // Input t-1
   int iMin;
   int iMax;
   bool initialized;
};

// -----------------------------------------------------------------------------
// Function declarations 
// -----------------------------------------------------------------------------

/** ----------------------------------------------------------------------------
 * PID_construct
 * Constructor for a PID regulator
 *
 * @param	self                       PID object to construct
 * @param	Kp                         proportional constant
 * @param   Ki                         integration constant
 * @param   Kd                         differential constant
 * @param   iMin                       Minimum value for integrator
 * @param   iMax                       Maximum value for integrator
 *
 * @return	ErrorStatus                SUCCESS if initialisation was successful
 *                                     ERRROR otherwise
 *
 * @todo
 * -----------------------------------------------------------------------------
 */
extern ErrorStatus PID_construct(struct Pid* self, int Kp, int Ki, int Kd, int iMin, int iMax);


/** ----------------------------------------------------------------------------
 * PID_destruct
 * Destructor for a PID regulator
 *
 * @param   self                       PID object to destruct
 *
 * @return  void
 *
 * @todo
 * -----------------------------------------------------------------------------
 */
extern void PID_destruct(struct Pid* self);


/** ----------------------------------------------------------------------------
 * PID_reset
 * Resets the pid regulator and cleans all history
 *
 * @param	self                       PID object to reset
 *
 * @return	void
 *
 * @todo
 * -----------------------------------------------------------------------------
 */
extern void PID_reset(struct Pid* self);


/** ----------------------------------------------------------------------------
 * PID_calculate
 * Calculate
 *
 * @param	self                       The PID object
 * @param   input                      The input
 * @param	error                      the error input to calculate
 *
 * @return	int                        calculated value
 *
 * @todo
 * -----------------------------------------------------------------------------
 */
extern int PID_calculate(struct Pid* self, int error);

#endif /* INC_PID_H_ */