File content as of revision 3:1a8c14043a4e:

/**
*   @file     AD5270.h
*   @brief    Header file for AD5270 rheostat
*   @author   Analog Devices Inc.
*
* For support please go to:
* Github: https://github.com/analogdevicesinc/mbed-adi
* Support: https://ez.analog.com/community/linux-device-drivers/microcontroller-no-os-drivers
* Product: http://www.analog.com/ad5270
* More: https://wiki.analog.com/resources/tools-software/mbed-drivers-all

********************************************************************************
* Copyright 2016(c) Analog Devices, Inc.
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*  - Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
*  - Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in
*    the documentation and/or other materials provided with the
*    distribution.
*  - Neither the name of Analog Devices, Inc. nor the names of its
*    contributors may be used to endorse or promote products derived
*    from this software without specific prior written permission.
*  - The use of this software may or may not infringe the patent rights
*    of one or more patent holders.  This license does not release you
*    from the requirement that you obtain separate licenses from these
*    patent holders to use this software.
*  - Use of the software either in source or binary form, must be run
*    on or directly connected to an Analog Devices Inc. component.
*
* THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
********************************************************************************/

#ifndef AD5270_H
#define AD5270_H

#include "mbed.h"

/**
 * @brief Analog Devices AD5270 SPI Digital Rheostat class
 */
class AD5270
{
public:

    /// AD5270 commands
    typedef enum {
        NO_OP               =  0x00,   ///< No data
        NO_OP_cmd           =  0x0000, ///< 16 bit no data
        WRITE_RDAC          =  0x04,   ///< Write to the RDAC Register
        READ_RDAC           =  0x08,   ///< Read from the RDAC Register
        STORE_50TP          =  0x0C,   ///< Write to the RDAC to memory
        SW_RST              =  0x10,   ///< Software reset to last memory location
        READ_50TP_CONTENTS  =  0x14,   ///< Read the last memory contents
        READ_50TP_ADDRESS   =  0x18,   ///< Read the last memory address
        WRITE_CTRL_REG      =  0x1C,   ///< Write to the control Register
        READ_CTRL_REG       =  0x20,   ///< Read from the control Register
        SW_SHUTDOWN         =  0x24,   ///< Software shutdown (0) - Normal, (1) - Shutdown
        HI_Zupper           =  0x80,   ///< Get the SDO line ready for High Z
        HI_Zlower           =  0x01,   ///< Puts AD5270 into High Z mode
        HI_Z_Cmd            =  0x8001   ///< Puts AD5270 into High Z mode*/
    } AD5270Commands_t;

    AD5270(PinName CS = SPI_CS, float max_resistance = 20000.0, PinName MOSI = SPI_MOSI, PinName MISO = SPI_MISO, PinName SCK = SPI_SCK);
    void set_SDO_HiZ(void);
    void frequency(int hz);
    uint16_t calc_RDAC(float resistance);
    uint16_t write_cmd(uint8_t command, uint16_t data = 0x00);
    uint16_t write_reg(uint16_t data);
    float get_max_resistance(void);

    SPI ad5270;    ///< SPI instance of the AD5270
    DigitalOut cs; ///< DigitalOut instance for the chipselect of the AD5270

private:
    const static int _RESET = 0xff;
    const static int _DUMMY_BYTE = 0xAA;
    float _max_resistance;
};

#endif