/********************************************************************************
*
* Embedded Studio (C) 2008                                   
*                                                                                
* File: ES_RvdtDrv.h
* Desc: Rotary Variable Differential Transformer (RVDT) Driver Functions
*
**********************************************************************************/

#ifndef __ES_RVDTDRV_H__
#define __ES_RVDTDRV_H__


/****************************************************************************
 Constant definitions. They are application dependent.
 ****************************************************************************/

#define RVDT_POS_GAIN				1.25		// Position Gain (in / ratio)
#define RVDT_POS_OFFSET				5.0			// Position Offset (in)

#define RVDT_POS_LIMIT_HI			10.0		// Position limit high
#define RVDT_POS_LIMIT_LO			-0.5	    // Position limit low

#define RVDT_POS_MID_STROKE         5.0			// middle stroke

#define RVDT_FAULT_ON_COUNT_MAX	    3			// fault on persistence 3 times
#define RVDT_FAULT_OFF_COUNT_MAX	30			// fault off persistence 30 times

#define RVDT_SUM_LIMIT_HI			5.5			// Vsum + 0.5
#define RVDT_SUM_LIMIT_LO			4.5			// Vsum - 0.5


/****************************************************************************
 data structures
 ****************************************************************************/

//RVDT data structure
typedef struct tRvdtDataStruct
{
	float Va;             //secondary voltage Va
	float Vb;             //secondary voltage Vb
	float Vsum;           //sum of Va and Vb
	float Vdiff;          //diff of Va and Vb
	float Position;       //current position
	float PosPrev;        //previous position
} RvdtDataStruct;

//RVDT status data structure
typedef struct tRvdtStatusStruct
{
	union
	{
    	struct
    	{
    		unsigned int rsvd             :29;
    	    unsigned int HiLimitFault     :1;	//position high limit fault
    	    unsigned int LoLimitFault     :1;	//position low limit fault
    	    unsigned int SumFault         :1;	//Vsum fault
    	}Bits;
    	unsigned int All;
	}Status;                                //status bits
	unsigned int SumFaultOnCounter;         //counter for sum fault on
	unsigned int SumFaultOffCounter;        //counter for sum fault off
	unsigned int HiLimitFaultOnCounter;     //counter for high limit fault on
	unsigned int HiLimitFaultOffCounter;    //counter for high limit fault off
	unsigned int LoLimitFaultOnCounter;     //counter for low limit fault on
	unsigned int LoLimitFaultOffCounter;    //counter for low limit fault off
} RvdtStatusStruct;

/****************************************************************************
 public functions
 ****************************************************************************/
bool RVDT_Init(void);
void RVDT_GetData(void);
float RVDT_GetPosition(void);
bool RVDT_IsDataValid(void);

#endif   
/****************************************************************************
 End of File
 ****************************************************************************/