Analog Devices / AD7791

Driver for the AD7791 24bit ADC

Dependents:   ad7791-helloworld CN0216

For additional information check out the mbed page of the Analog Devices wiki: https://wiki.analog.com/resources/tools-software/mbed-drivers-all

AD7791.h@0:075fe3d08488, 2016-05-03 (annotated)

Committer:
adisuciu
Date:
Tue May 03 12:57:07 2016 +0000
Revision:
0:075fe3d08488
Initial revision

Who changed what in which revision?

UserRevisionLine numberNew contents of line
adisuciu 0:075fe3d08488 1 /**
adisuciu 0:075fe3d08488 2 * @file AD7791.h
adisuciu 0:075fe3d08488 3 * @brief Header file for AD7791 ADC
adisuciu 0:075fe3d08488 4 * @author Analog Devices Inc.
adisuciu 0:075fe3d08488 5 *
adisuciu 0:075fe3d08488 6 * For support please go to:
adisuciu 0:075fe3d08488 7 * Github: https://github.com/analogdevicesinc/mbed-adi
adisuciu 0:075fe3d08488 8 * Support: https://ez.analog.com/community/linux-device-drivers/microcontroller-no-os-drivers
adisuciu 0:075fe3d08488 9 * Product: http://www.analog.com/ad7791
adisuciu 0:075fe3d08488 10 * More: https://wiki.analog.com/resources/tools-software/mbed-drivers-all
adisuciu 0:075fe3d08488 11
adisuciu 0:075fe3d08488 12 ********************************************************************************
adisuciu 0:075fe3d08488 13 * Copyright 2016(c) Analog Devices, Inc.
adisuciu 0:075fe3d08488 14 *
adisuciu 0:075fe3d08488 15 * All rights reserved.
adisuciu 0:075fe3d08488 16 *
adisuciu 0:075fe3d08488 17 * Redistribution and use in source and binary forms, with or without
adisuciu 0:075fe3d08488 18 * modification, are permitted provided that the following conditions are met:
adisuciu 0:075fe3d08488 19 * - Redistributions of source code must retain the above copyright
adisuciu 0:075fe3d08488 20 * notice, this list of conditions and the following disclaimer.
adisuciu 0:075fe3d08488 21 * - Redistributions in binary form must reproduce the above copyright
adisuciu 0:075fe3d08488 22 * notice, this list of conditions and the following disclaimer in
adisuciu 0:075fe3d08488 23 * the documentation and/or other materials provided with the
adisuciu 0:075fe3d08488 24 * distribution.
adisuciu 0:075fe3d08488 25 * - Neither the name of Analog Devices, Inc. nor the names of its
adisuciu 0:075fe3d08488 26 * contributors may be used to endorse or promote products derived
adisuciu 0:075fe3d08488 27 * from this software without specific prior written permission.
adisuciu 0:075fe3d08488 28 * - The use of this software may or may not infringe the patent rights
adisuciu 0:075fe3d08488 29 * of one or more patent holders. This license does not release you
adisuciu 0:075fe3d08488 30 * from the requirement that you obtain separate licenses from these
adisuciu 0:075fe3d08488 31 * patent holders to use this software.
adisuciu 0:075fe3d08488 32 * - Use of the software either in source or binary form, must be run
adisuciu 0:075fe3d08488 33 * on or directly connected to an Analog Devices Inc. component.
adisuciu 0:075fe3d08488 34 *
adisuciu 0:075fe3d08488 35 * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
adisuciu 0:075fe3d08488 36 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
adisuciu 0:075fe3d08488 37 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
adisuciu 0:075fe3d08488 38 * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
adisuciu 0:075fe3d08488 39 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
adisuciu 0:075fe3d08488 40 * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
adisuciu 0:075fe3d08488 41 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
adisuciu 0:075fe3d08488 42 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
adisuciu 0:075fe3d08488 43 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
adisuciu 0:075fe3d08488 44 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
adisuciu 0:075fe3d08488 45 *
adisuciu 0:075fe3d08488 46 ********************************************************************************/
adisuciu 0:075fe3d08488 47
adisuciu 0:075fe3d08488 48 #ifndef AD7791_H
adisuciu 0:075fe3d08488 49 #define AD7791_H
adisuciu 0:075fe3d08488 50
adisuciu 0:075fe3d08488 51 #include "mbed.h"
adisuciu 0:075fe3d08488 52
adisuciu 0:075fe3d08488 53 /**
adisuciu 0:075fe3d08488 54 * Comment this line if you want to turn off the debug mode.
adisuciu 0:075fe3d08488 55 * The debug mode will send a message if an exception occurs within AD7791 driver
adisuciu 0:075fe3d08488 56 */
adisuciu 0:075fe3d08488 57
adisuciu 0:075fe3d08488 58 #define AD7791_DEBUG_MODE
adisuciu 0:075fe3d08488 59
adisuciu 0:075fe3d08488 60 /**
adisuciu 0:075fe3d08488 61 * @brief Analog Devices AD7791 SPI 16-bit Buffered Sigma-Delta ADC
adisuciu 0:075fe3d08488 62 */
adisuciu 0:075fe3d08488 63 class AD7791
adisuciu 0:075fe3d08488 64 {
adisuciu 0:075fe3d08488 65 public:
adisuciu 0:075fe3d08488 66 /// AD7791 registers
adisuciu 0:075fe3d08488 67 typedef enum {
adisuciu 0:075fe3d08488 68 COMMUNICATION_REG = 0, ///< Communication register
adisuciu 0:075fe3d08488 69 STATUS_REG = 0, ///< Status register
adisuciu 0:075fe3d08488 70 MODE_REG, ///< Mode register
adisuciu 0:075fe3d08488 71 FILTER_REG, ///< Filter Register
adisuciu 0:075fe3d08488 72 DATA_REG ///< Data register
adisuciu 0:075fe3d08488 73 } AD7791Register_t;
adisuciu 0:075fe3d08488 74
adisuciu 0:075fe3d08488 75 /// AD7791 channel configuration
adisuciu 0:075fe3d08488 76 typedef enum {
adisuciu 0:075fe3d08488 77 DIFFERENTIAL = 0, ///< AIN(+)-AIN(-)
adisuciu 0:075fe3d08488 78 RESERVED, ///< reserved
adisuciu 0:075fe3d08488 79 SHORT, ///< AIN(-)-AIN(-)
adisuciu 0:075fe3d08488 80 VDDMONITOR ///< Monitor VDD
adisuciu 0:075fe3d08488 81 } AD7791Channel_t;
adisuciu 0:075fe3d08488 82
adisuciu 0:075fe3d08488 83 typedef enum {
adisuciu 0:075fe3d08488 84 CONTINOUS_CONVERSION_MODE = 0,
adisuciu 0:075fe3d08488 85 SINGLE_CONVERSION_MODE = 0x80,
adisuciu 0:075fe3d08488 86 SHUTDOWN_MODE = 0xC0
adisuciu 0:075fe3d08488 87 } AD7791Mode_t;
adisuciu 0:075fe3d08488 88
adisuciu 0:075fe3d08488 89 typedef enum {
adisuciu 0:075fe3d08488 90 MD1 = 0x80, ///< Mode Select Bit 1
adisuciu 0:075fe3d08488 91 MD0 = 0x40, ///< Mode Select Bit 0
adisuciu 0:075fe3d08488 92 // G1 = 0x20, ///< Range bit 1
adisuciu 0:075fe3d08488 93 // G0 = 0x10, ///< Range bit 0
adisuciu 0:075fe3d08488 94 BO = 0x08, ///< Burnout Current Enable bit
adisuciu 0:075fe3d08488 95 UB = 0x04, ///< Unipolar/Bipolar bit
adisuciu 0:075fe3d08488 96 BUF = 0x02, ///< Buffered mode bit
adisuciu 0:075fe3d08488 97 } ModeRegisterBits_t;
adisuciu 0:075fe3d08488 98
adisuciu 0:075fe3d08488 99 typedef enum {
adisuciu 0:075fe3d08488 100 CLKDIV1 = 0x40, ///< Clock divider bit 1
adisuciu 0:075fe3d08488 101 CLKDIV0 = 0x20, ///< Clock divider bit 0
adisuciu 0:075fe3d08488 102 FS2 = 0x04, ///< Update rate bit 2
adisuciu 0:075fe3d08488 103 FS1 = 0x02, ///< Update rate bit 1
adisuciu 0:075fe3d08488 104 FS0 = 0x01, ///< Update rate bit 0
adisuciu 0:075fe3d08488 105 } FilterRegisterBits_t;
adisuciu 0:075fe3d08488 106
adisuciu 0:075fe3d08488 107 /* typedef enum {
adisuciu 0:075fe3d08488 108 RANGE_VREF = 0,
adisuciu 0:075fe3d08488 109 RANGE_VREF_DIV_2,
adisuciu 0:075fe3d08488 110 RANGE_VREF_DIV_4,
adisuciu 0:075fe3d08488 111 RANGE_VREF_DIV_8,
adisuciu 0:075fe3d08488 112 } AnalogInputRange_t;
adisuciu 0:075fe3d08488 113 */
adisuciu 0:075fe3d08488 114 /** SPI configuration & constructor */
adisuciu 0:075fe3d08488 115 AD7791( float reference_voltage, PinName CS = SPI_CS, PinName MOSI = SPI_MOSI, PinName MISO = SPI_MISO, PinName SCK = SPI_SCK);
adisuciu 0:075fe3d08488 116 void frequency(int hz);
adisuciu 0:075fe3d08488 117
adisuciu 0:075fe3d08488 118 /** Low level SPI bus comm methods */
adisuciu 0:075fe3d08488 119 void reset(void);
adisuciu 0:075fe3d08488 120
adisuciu 0:075fe3d08488 121 /** Register access methods*/
adisuciu 0:075fe3d08488 122 void set_channel(AD7791Channel_t channel);
adisuciu 0:075fe3d08488 123 void set_conversion_mode(AD7791Mode_t mode);
adisuciu 0:075fe3d08488 124 uint32_t read_data_reg();
adisuciu 0:075fe3d08488 125 uint8_t read_status_reg(void);
adisuciu 0:075fe3d08488 126 void write_filter_reg(uint8_t regVal);
adisuciu 0:075fe3d08488 127 uint8_t read_filter_reg(void);
adisuciu 0:075fe3d08488 128 void write_mode_reg(uint8_t regVal);
adisuciu 0:075fe3d08488 129 uint8_t read_mode_reg(void);
adisuciu 0:075fe3d08488 130 // void set_range(AnalogInputRange_t range);
adisuciu 0:075fe3d08488 131 // AnalogInputRange_t get_range(void);
adisuciu 0:075fe3d08488 132
adisuciu 0:075fe3d08488 133 /** Reference voltage methods */
adisuciu 0:075fe3d08488 134 void set_reference_voltage(float ref);
adisuciu 0:075fe3d08488 135 float get_reference_voltage(void);
adisuciu 0:075fe3d08488 136
adisuciu 0:075fe3d08488 137 /** Voltage read methods */
adisuciu 0:075fe3d08488 138 float read_voltage(void);
adisuciu 0:075fe3d08488 139 float data_to_voltage(uint32_t data);
adisuciu 0:075fe3d08488 140 uint32_t voltage_to_data(float voltage);
adisuciu 0:075fe3d08488 141
adisuciu 0:075fe3d08488 142 /** AnalogIn API */
adisuciu 0:075fe3d08488 143 float read(void);
adisuciu 0:075fe3d08488 144 uint32_t read_u32(void);
adisuciu 0:075fe3d08488 145 uint16_t read_u16(void);
adisuciu 0:075fe3d08488 146
adisuciu 0:075fe3d08488 147 #ifdef MBED_OPERATORS
adisuciu 0:075fe3d08488 148 operator float();
adisuciu 0:075fe3d08488 149 #endif
adisuciu 0:075fe3d08488 150
adisuciu 0:075fe3d08488 151 private:
adisuciu 0:075fe3d08488 152 DigitalIn miso;
adisuciu 0:075fe3d08488 153 SPI ad7791; ///< SPI instance of the AD7791
adisuciu 0:075fe3d08488 154 DigitalOut cs; ///< DigitalOut instance for the chipselect of the AD7791
adisuciu 0:075fe3d08488 155
adisuciu 0:075fe3d08488 156 float _vref;
adisuciu 0:075fe3d08488 157 // uint8_t _PGA_gain;
adisuciu 0:075fe3d08488 158 bool _continous_conversion;
adisuciu 0:075fe3d08488 159 AD7791Channel_t _channel;
adisuciu 0:075fe3d08488 160
adisuciu 0:075fe3d08488 161 void write_reg(AD7791Register_t regAddress, uint8_t regValue);
adisuciu 0:075fe3d08488 162 uint16_t write_spi(uint16_t data);
adisuciu 0:075fe3d08488 163 uint16_t read_reg (AD7791Register_t regAddress);
adisuciu 0:075fe3d08488 164
adisuciu 0:075fe3d08488 165 const static uint16_t _SINGLE_CONVERSION_TIMEOUT = 0xFFFF; // in 10us = 100ms
adisuciu 0:075fe3d08488 166 const static uint16_t _CONTINOUS_CONVERSION_TIMEOUT = 0xFFFF;
adisuciu 0:075fe3d08488 167 const static uint32_t _RESOLUTION = 0xFFFFFF;
adisuciu 0:075fe3d08488 168 const static uint8_t _RESET = 0xFF;
adisuciu 0:075fe3d08488 169 const static uint8_t _DUMMY_BYTE = 0xFF;
adisuciu 0:075fe3d08488 170 const static uint16_t _READ_FLAG = 0x0800;
adisuciu 0:075fe3d08488 171 const static uint8_t _DATA_READ = 0x38; // Read from the Data Register
adisuciu 0:075fe3d08488 172 const static uint8_t _DELAY_TIMING = 0x02;
adisuciu 0:075fe3d08488 173 const static uint8_t _SPI_MODE = 3;
adisuciu 0:075fe3d08488 174 };
adisuciu 0:075fe3d08488 175
adisuciu 0:075fe3d08488 176 #endif