Analog Devices AD7790 SPI 16-bit Buffered Sigma-Delta ADC. More...

#include <AD7790.h>

Public Types
enum	AD7790Register_t { COMMUNICATION_REG = 0, STATUS_REG = 0, MODE_REG, FILTER_REG, DATA_REG }
	AD7790 registers. More...
enum	AD7790Channel_t { DIFFERENTIAL = 0, RESERVED, SHORT, VDDMONITOR }
	AD7790 channel configuration. More...
enum	ModeRegisterBits_t { MD1 = 0x80, MD0 = 0x40, G1 = 0x20, G0 = 0x10, BO = 0x08, BUF = 0x02 }
enum	FilterRegisterBits_t { CLKDIV1 = 0x40, CLKDIV0 = 0x20, FS2 = 0x04, FS1 = 0x02, FS0 = 0x01 }
Public Member Functions
	AD7790 (float reference_voltage, PinName CS=SPI_CS, PinName MOSI=SPI_MOSI, PinName MISO=SPI_MISO, PinName SCK=SPI_SCK)
	SPI configuration & constructor.
void	frequency (int hz)
	Set AD7790 SPI frequency.
void	reset (void)
	Low level SPI bus comm methods.
void	set_channel (AD7790Channel_t channel)
	Register access methods.
void	set_conversion_mode (AD7790Mode_t mode)
	Enables/disables continous_conversion mode In Single Conversion mode, read_u16 method will read the MODE register of the ADC, then write the Start single conversion bit and wait for the DOUT/RDY pin to go low, When the pin is driven low, data register is read back from the ADC.
uint16_t	read_data_reg ()
	Reads the data register and returns its value.
uint8_t	read_status_reg (void)
	Reads the status register of the ADC and returns its value.
void	write_filter_reg (uint8_t regVal)
	Writes the filter register.
uint8_t	read_filter_reg (void)
	Reads the filter register and returns its value.
void	write_mode_reg (uint8_t regVal)
	Sets the mode register.
uint8_t	read_mode_reg (void)
	Reads the mode register and returns its value.
void	set_range (AnalogInputRange_t range)
	Sets the AnalogInputRange to be used by the AD7790.
void	set_reference_voltage (float ref)
	Reference voltage methods.
float	get_reference_voltage (void)
	Gets the reference voltage of the AD7790.
float	read_voltage (void)
	Voltage read methods.
float	data_to_voltage (uint16_t data)
	Converts an uint16_t to voltage.
uint16_t	voltage_to_data (float voltage)
	Converts voltage to an uint16_t.
float	read (void)
	AnalogIn API.
uint16_t	read_u16 (void)
	From mbed AnalogIn API -
	operator float ()
	From mbed AnalogIn API - An operator shorthand for read() The float() operator can be used as a shorthand for read() to simplify common code sequences

Detailed Description

Analog Devices AD7790 SPI 16-bit Buffered Sigma-Delta ADC.

Definition at line 63 of file AD7790.h.

Member Enumeration Documentation

enum AD7790Channel_t

AD7790 channel configuration.

Enumerator:

DIFFERENTIAL	AIN(+)-AIN(-)
RESERVED	reserved
SHORT	AIN(-)-AIN(-)
VDDMONITOR	Monitor VDD.

Definition at line 76 of file AD7790.h.

enum AD7790Register_t

AD7790 registers.

Enumerator:

COMMUNICATION_REG	Communication register.
STATUS_REG	Status register.
MODE_REG	Mode register.
FILTER_REG	Filter Register.
DATA_REG	Data register.

Definition at line 67 of file AD7790.h.

enum FilterRegisterBits_t

Enumerator:

CLKDIV1	Clock divider bit 1.
CLKDIV0	Clock divider bit 0.
FS2	Update rate bit 2.
FS1	Update rate bit 1.
FS0	Update rate bit 0.

Definition at line 98 of file AD7790.h.

enum ModeRegisterBits_t

Enumerator:

MD1	Mode Select Bit 1.
MD0	Mode Select Bit 0.
G1	Range bit 1.
G0	Range bit 0.
BO	Burnout Current Enable bit.
BUF	Buffered mode bit.

Definition at line 89 of file AD7790.h.

Constructor & Destructor Documentation

AD7790	(	float	reference_voltage,
		PinName	CS = `SPI_CS`,
		PinName	MOSI = `SPI_MOSI`,
		PinName	MISO = `SPI_MISO`,
		PinName	SCK = `SPI_SCK`
	)

SPI configuration & constructor.

AD7790 constructor, sets CS pin and SPI format.

Parameters:

CS	- (optional)chip select of the AD7790
MOSI	- (optional)pin of the SPI interface
MISO	- (optional)pin of the SPI interface
SCK	- (optional)pin of the SPI interface

Definition at line 59 of file AD7790.cpp.

Member Function Documentation

float data_to_voltage ( uint16_t data )

Converts an uint16_t to voltage.

Gain needs to be correctly set using set_gain in order to get accurate results

Parameters:

data	in uint16_t format

Returns:: float value of voltage (in V)

Definition at line 344 of file AD7790.cpp.

void frequency ( int hz )

Set AD7790 SPI frequency.

Parameters:

hz	- SPI bus frequency in hz

Returns:: none

Definition at line 77 of file AD7790.cpp.

float get_reference_voltage ( void )

Gets the reference voltage of the AD7790.

Returns:: reference voltage

Definition at line 323 of file AD7790.cpp.

operator float ( )

From mbed AnalogIn API - An operator shorthand for read() The float() operator can be used as a shorthand for read() to simplify common code sequences

Definition at line 391 of file AD7790.cpp.

float read ( void )

AnalogIn API.

From mbed AnalogIn API - Read the input voltage, represented as a float in the range [0.0, 1.0] - uses the read_u16 method

Returns:: A floating-point value representing the current input voltage, measured as a percentage returns 1.0 along with a debug message if the conversion failed

Definition at line 375 of file AD7790.cpp.

uint16_t read_data_reg ( )

Reads the data register and returns its value.

Returns:: value of the data register

Definition at line 149 of file AD7790.cpp.

uint8_t read_filter_reg ( void )

Reads the filter register and returns its value.

Returns:: the value of the filter register

Definition at line 140 of file AD7790.cpp.

uint8_t read_mode_reg ( void )

Reads the mode register and returns its value.

Returns:: value of the mode register

Definition at line 122 of file AD7790.cpp.

uint8_t read_status_reg ( void )

Reads the status register of the ADC and returns its value.

Returns:: value of the status reg

Definition at line 165 of file AD7790.cpp.

uint16_t read_u16 ( void )

From mbed AnalogIn API -

Read the input voltage, represented as an unsigned short in the range [0x0, 0xFFFF] Depending on the conversion mode, this method will have different behavior. Conversion mode is set using set_continous_conversion_mode(bool).

In Single Conversion mode, read_u16 method will read the MODE register of the ADC, then write the Start single conversion bit and wait for the DOUT/RDY pin to go low, When the pin is driven low, data register is read back from the ADC.

In Continous conversion mode, read_u16 method will poll the DOUT/RDY pin, if it is low, the data register is read back from the ADC.

Returns:: 16-bit unsigned short representing the current input voltage, normalised to a 16-bit value returns -1 (0xFFFF) along with a debug message if conversion failed.

Definition at line 208 of file AD7790.cpp.

float read_voltage ( void )

Voltage read methods.

Reads the data register of the ADC and converts the result to volts Gain needs to be correctly set using set_gain in order to get accurate results.

Returns:: voltage of the ADC input

Definition at line 333 of file AD7790.cpp.

void reset ( void )

Low level SPI bus comm methods.

Resets the AD7790.

Returns:: none

Definition at line 86 of file AD7790.cpp.

void set_channel ( AD7790Channel_t channel )

Register access methods.

Sets the conversion channel.

Parameters:

channel

Definition at line 364 of file AD7790.cpp.

void set_conversion_mode ( AD7790Mode_t mode )

Enables/disables continous_conversion mode In Single Conversion mode, read_u16 method will read the MODE register of the ADC, then write the Start single conversion bit and wait for the DOUT/RDY pin to go low, When the pin is driven low, data register is read back from the ADC.

In Continous conversion mode, read_u16 method will poll the DOUT/RDY pin, if it is low, the data register is read back from the ADC.

Parameters:

mode	true - continous conversion mode enabled false - single conversion mode enabled

Definition at line 184 of file AD7790.cpp.

void set_range ( AnalogInputRange_t range )

Sets the AnalogInputRange to be used by the AD7790.

Parameters:

range AnalogInputRange_t to be used in voltage computations

Definition at line 301 of file AD7790.cpp.

void set_reference_voltage ( float ref )

Reference voltage methods.

Sets the reference voltage of the AD7790.

Parameters:

ref	reference voltage to be set

Definition at line 314 of file AD7790.cpp.

uint16_t voltage_to_data ( float voltage )

Converts voltage to an uint16_t.

Gain needs to be correctly set using set_gain in order to get accurate results

Parameters:

voltage to be converted

Returns:: data in uint16_t format

Definition at line 355 of file AD7790.cpp.

void write_filter_reg ( uint8_t reg_val )

Writes the filter register.

Parameters:

regValue value to be written.

Definition at line 131 of file AD7790.cpp.

void write_mode_reg ( uint8_t reg_val )

Sets the mode register.

Also sets continous mode and range based on the value written in reg_val

Parameters:

reg_val

Definition at line 105 of file AD7790.cpp.

Type:	Library
Created:	21 Apr 2016
Imports:	104
Forks:	0
Commits:	34
Dependents:	0
Dependencies:	0
Followers:	109

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AD7790 Class Reference

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Components

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