FDC1004.h

/**************************
 This is a library for the FDC1004 Capacitance Sensor

 Written by Benjamin Shaya
**************************/

#ifndef _FDC1004
#define _FDC1004

#include "Arduino.h"
#include "Wire.h"

//Constants and limits for FDC1004
#define FDC1004_100HZ (0x01)
#define FDC1004_200HZ (0x02)
#define FDC1004_400HZ (0x03)
#define FDC1004_IS_RATE(x) (x == FDC1004_100HZ || \
                            x == FDC1004_200HZ || \
                            x == FDC1004_400HZ)

#define FDC1004_CAPDAC_MAX (0x1F)

#define FDC1004_CHANNEL_MAX (0x03)
#define FDC1004_IS_CHANNEL(x) (x >= 0 && x <= FDC1004_CHANNEL_MAX)
 
#define FDC1004_MEAS_MAX (0x03)
#define FDC1004_IS_MEAS(x) (x >= 0 && x <= FDC1004_MEAS_MAX)
                             
#define FDC_REGISTER (0x0C)

// number of attofarads for each 8th most lsb (lsb of the upper 16 bit half-word)
#define ATTOFARADS_UPPER_WORD (488)

// number of femtofarads for each lsb of the capdac
#define FEMTOFARADS_CAPDAC (3125)
                             
/********************************************************************************************************
 * typedefs
 *******************************************************************************************************/
typedef struct fdc1004_measurement_t{
    int16_t value;
    uint8_t capdac;
}fdc1004_measurement_t;

/******************************************************************************************
 * Function Declarations
 ******************************************************************************************/ 
class FDC1004 {
 public:
    FDC1004(uint16_t rate = FDC1004_100HZ);
    int32_t getCapacitance(uint8_t channel = 1);
    uint8_t getRawCapacitance(uint8_t channel, fdc1004_measurement_t * value);
    uint8_t configureMeasurementSingle(uint8_t measurement, uint8_t channel, uint8_t capdac); 
    uint8_t triggerSingleMeasurement(uint8_t measurement, uint8_t rate);
    uint8_t readMeasurement(uint8_t measurement, uint16_t * value);
    uint8_t measureChannel(uint8_t channel, uint8_t capdac, uint16_t * value);


 private:
    uint8_t _addr;
    uint8_t _rate;
    uint8_t _last_capdac[4];
    void write16(uint8_t reg, uint16_t data);
    uint16_t read16(uint8_t reg);
};

#endif