File content as of revision 0:fb6fe6fa2835:

#ifndef _AD7798_H_
#define _AD7798_H_

#include <mbed.h>

/******************************************************************************/
/* AD7798                                                                   */
/******************************************************************************/

/*AD7798 Registers*/
#define AD7798_REG_COMM		0 /* Communications Register(WO, 8-bit) */
#define AD7798_REG_STAT	    0 /* Status Register	    (RO, 8-bit) */
#define AD7798_REG_MODE	    1 /* Mode Register	     	(RW, 16-bit */
#define AD7798_REG_CONF	    2 /* Configuration Register (RW, 16-bit)*/
#define AD7798_REG_DATA	    3 /* Data Register	     	(RO, 16-/24-bit) */
#define AD7798_REG_ID	    4 /* ID Register	     	(RO, 8-bit) */
#define AD7798_REG_IO	    5 /* IO Register	     	(RO, 8-bit) */
#define AD7798_REG_OFFSET   6 /* Offset Register	    (RW, 24-bit */
#define AD7798_REG_FULLSCALE	7 /* Full-Scale Register	(RW, 24-bit */

/* Communications Register Bit Designations (AD7798_REG_COMM) */
#define AD7798_COMM_WEN		(1 << 7) 			/* Write Enable */
#define AD7798_COMM_WRITE	(0 << 6) 			/* Write Operation */
#define AD7798_COMM_READ    (1 << 6) 			/* Read Operation */
#define AD7798_COMM_ADDR(x)	(((x) & 0x7) << 3)	/* Register Address */
#define AD7798_COMM_CREAD	(1 << 2) 			/* Continuous Read of Data Register */

/* Status Register Bit Designations (AD7798_REG_STAT) */
#define AD7798_STAT_RDY		(1 << 7) /* Ready */
#define AD7798_STAT_ERR		(1 << 6) /* Error (Overrange, Underrange) */
#define AD7798_STAT_CH3		(1 << 2) /* Channel 3 */
#define AD7798_STAT_CH2		(1 << 1) /* Channel 2 */
#define AD7798_STAT_CH1		(1 << 0) /* Channel 1 */


#define AD7798_CH3		(1 << 2) /* Channel 3 */
#define AD7798_CH2		(1 << 1) /* Channel 2 */
#define AD7798_CH1		(1 << 0) /* Channel 1 */

/* Mode Register Bit Designations (AD7798_REG_MODE) */
#define AD7798_MODE_SEL(x)		(((x) & 0x7) << 13)	/* Operation Mode Select */
#define AD7798_MODE_PSW(x)		(1 << 12)			/* Power Switch Control Bit */
#define AD7798_MODE_RATE(x)		((x) & 0xF) 		/* Filter Update Rate Select */

/* AD7798_MODE_SEL(x) options */
#define AD7798_MODE_CONT		 0 /* Continuous Conversion Mode */
#define AD7798_MODE_SINGLE		 1 /* Single Conversion Mode */
#define AD7798_MODE_IDLE		 2 /* Idle Mode */
#define AD7798_MODE_PWRDN		 3 /* Power-Down Mode */
#define AD7798_MODE_CAL_INT_ZERO 4 /* Internal Zero-Scale Calibration */
#define AD7798_MODE_CAL_INT_FULL 5 /* Internal Full-Scale Calibration */
#define AD7798_MODE_CAL_SYS_ZERO 6 /* System Zero-Scale Calibration */
#define AD7798_MODE_CAL_SYS_FULL 7 /* System Full-Scale Calibration */

/* Configuration Register Bit Designations (AD7798_REG_CONF) */
#define AD7798_CONF_BO_EN	  (1 << 13) 			/* Burnout Current Enable */
#define AD7798_CONF_UNIPOLAR  (1 << 12) 			/* Unipolar/Bipolar Enable */
#define AD7798_CONF_GAIN(x)	  (((x) & 0x7) << 8) 	/* Gain Select */
#define AD7798_CONF_REFDET(x) (((x) & 0x1) << 5) 	/* Reference detect function */
#define AD7798_CONF_BUF		  (1 << 4) 				/* Buffered Mode Enable */
#define AD7798_CONF_CHAN(x)	  ((x) & 0x7) 			/* Channel select */

/* AD7798_CONF_GAIN(x) options */
#define AD7798_GAIN_1       0
#define AD7798_GAIN_2       1
#define AD7798_GAIN_4       2
#define AD7798_GAIN_8       3
#define AD7798_GAIN_16      4
#define AD7798_GAIN_32      5
#define AD7798_GAIN_64      6
#define AD7798_GAIN_128     7

/* AD7798_CONF_REFDET(x) options */
#define AD7798_REFDET_ENA   1
#define AD7798_REFDET_DIS   0

/* AD7798_CONF_CHAN(x) options */
#define AD7798_CH_AIN1P_AIN1M	0 /* AIN1(+) - AIN1(-) */
#define AD7798_CH_AIN2P_AIN2M	1 /* AIN2(+) - AIN2(-) */
#define AD7798_CH_AIN3P_AIN3M	2 /* AIN3(+) - AIN3(-) */
#define AD7798_CH_AIN1M_AIN1M	3 /* AIN1(-) - AIN1(-) */
#define AD7798_CH_AVDD_MONITOR	7 /* AVDD Monitor */

/* ID Register Bit Designations (AD7798_REG_ID) */
#define AD7798_ID			0x8
#define AD7798_ID_MASK		0xF

/* IO (Excitation Current Sources) Register Bit Designations (AD7798_REG_IO) */
#define AD7798_IOEN			(1 << 6)
#define AD7798_IO1(x)		(((x) & 0x1) << 4)
#define AD7798_IO2(x)		(((x) & 0x1) << 5)

#define TRUE              1
#define FALSE             0

#define AD7798_UNIPOLAR     TRUE
#define AD7798_BIPOLAR      FALSE

#define AD7798_ENABLE       TRUE
#define AD7798_DISABLE      FALSE

/******************************************************************************/
/* Functions Prototypes                                                       */
/*****************************************************************************/

class AD7798
{
public:
    AD7798( PinName CS, PinName MOSI = SPI_MOSI, PinName MISO = SPI_MISO, PinName SCK = SPI_SCK);
    /* Initialize AD7798 and check if the device is present*/
    uint8_t init(void);
    void frequency(int hz);
    /* Sends 32 consecutive 1's on SPI in order to reset the part. */
    void reset(void);
    /* Reads the value of the selected register. */
    uint16_t get_register_value(uint8_t regAddress, uint8_t size, bool toggle_cs = true);
    /* Writes a value to the register. */
    void set_register_value(uint8_t regAddress, uint16_t regValue, uint8_t size, bool toggle_cs = true);
    /* Sets the operating mode of AD7798. */
    void set_mode(uint8_t mode);
    /* Reads /RDY bit of Status register. */
    uint8_t ready(void);
    /* Selects the channel of AD7798. */
    void set_channel(uint8_t channel);
    /* Sets the gain of the In-Amp. */
    void set_gain(uint16_t gain);
    /* Enables or disables the reference detect function. */
    void set_reference(uint8_t state);

    void set_filter(uint8_t filter);
    void set_coding_mode(uint8_t mode);
    void set_burnout_current(uint8_t select);

    void read_data(uint8_t adcChannel, uint16_t *adcData);

    uint8_t spi_read(uint8_t *data, uint8_t bytes_number, bool toggle_cs = true);
    uint8_t spi_write(uint8_t *data, uint8_t bytes_number, bool toggle_cs = true);



    //DigitalIn miso;///< DigitalIn must be initialized before SPI to prevent pin MUX overwrite
    SPI ad7798;
    DigitalOut cs;

private:
    const uint8_t _SPI_MODE = 0x03;
};
#endif	// _AD7798_H_