duds::hardware::devices::instruments::INA219 Class Reference

Preliminary support for TI's INA219 voltage and current sensor. More...

#include <INA219.hpp>

Inheritance diagram for duds::hardware::devices::instruments::INA219:

Collaboration diagram for duds::hardware::devices::instruments::INA219:

Public Member Functions
	INA219 (std::unique_ptr< duds::hardware::interface::Smbus > &c, double sr)
	~INA219 ()
duds::data::Quantity	busCurrent () const
	Returns the computed bus current using the sampled shunt voltage and the shunt resistance. More...
duds::data::Quantity	busPower () const
	Returns the computed bus power using the sampled bus voltage and the computed bus current. More...
duds::data::Quantity	busVoltage () const
	Returns the sampled bus voltage. More...
duds::data::Quantity	maxCurrent () const
	Returns the maximum current that can be measured by the device. More...
void	sample ()
	Reads sample data from the device. More...
duds::data::Quantity	shuntResistance () const
	Returns the shunt resistance. More...
duds::data::Quantity	shuntVoltage () const
	Returns the sampled shunt voltage. More...
void	vals (std::int16_t &sV, std::int16_t &bV)

Private Attributes
std::int16_t	busV
	The raw data for the sampled bus voltage. More...
std::unique_ptr< duds::hardware::interface::Smbus >	com
	Communication bus. More...
double	shunt
	Shunt resistance; used to compute current. More...
std::int16_t	shuntV
	The raw data for the sampled shunt voltage. More...

Detailed Description

Preliminary support for TI's INA219 voltage and current sensor.

This device measures two voltages in a way that allows computation of current and power. The current must pass through a shunt resistor. The voltage across that resistor, and the voltage between there and ground, is measured. This class can compute the power and current based on these measurements, but it needs to know the shunt resistance for these computations.

Normally uses address 0x40. Does not use PEC; not really a SMBus device.

Author

Jeff Jackowski

Examples:

ina219test.cpp.

Definition at line 31 of file INA219.hpp.

Constructor & Destructor Documentation

INA219()

duds::hardware::devices::instruments::INA219::INA219	(	std::unique_ptr< duds::hardware::interface::Smbus > &	c,
		double	sr
	)

Todo:

Find way to reject bad SMBus config.

Maybe find way to produce SMBus config.

Parameters

c	The SMBus interface to use for communication. PEC must be disabled.
sr	The shunt resistance in ohms.

Definition at line 14 of file INA219.cpp.

~INA219()

duds::hardware::devices::instruments::INA219::~INA219

(

)

Definition at line 25 of file INA219.cpp.

Member Function Documentation

busCurrent()

duds::data::Quantity duds::hardware::devices::instruments::INA219::busCurrent

(

)

const

Returns the computed bus current using the sampled shunt voltage and the shunt resistance.

Examples:

ina219test.cpp.

Definition at line 48 of file INA219.cpp.

Referenced by busPower().

busPower()

duds::data::Quantity duds::hardware::devices::instruments::INA219::busPower

(

)

const

Returns the computed bus power using the sampled bus voltage and the computed bus current.

Definition at line 52 of file INA219.cpp.

busVoltage()

duds::data::Quantity duds::hardware::devices::instruments::INA219::busVoltage

(

)

const

Returns the sampled bus voltage.

Examples:

ina219test.cpp.

Definition at line 44 of file INA219.cpp.

Referenced by busPower().

maxCurrent()

duds::data::Quantity duds::hardware::devices::instruments::INA219::maxCurrent

(

)

const

Returns the maximum current that can be measured by the device.

This value changes with the shunt resistance.

Definition at line 32 of file INA219.cpp.

sample()

void duds::hardware::devices::instruments::INA219::sample

(

)

Reads sample data from the device.

Examples:

ina219test.cpp.

Definition at line 56 of file INA219.cpp.

shuntResistance()

duds::data::Quantity duds::hardware::devices::instruments::INA219::shuntResistance

(

)

const

Returns the shunt resistance.

Definition at line 36 of file INA219.cpp.

Referenced by busCurrent().

shuntVoltage()

duds::data::Quantity duds::hardware::devices::instruments::INA219::shuntVoltage

(

)

const

Returns the sampled shunt voltage.

Examples:

ina219test.cpp.

Definition at line 40 of file INA219.cpp.

Referenced by busCurrent().

vals()

void duds::hardware::devices::instruments::INA219::vals ( std::int16_t &  sV, std::int16_t &  bV  )

inline

Examples:

ina219test.cpp.

Definition at line 93 of file INA219.hpp.

Member Data Documentation

busV

std::int16_t duds::hardware::devices::instruments::INA219::busV

private

The raw data for the sampled bus voltage.

Definition at line 47 of file INA219.hpp.

Referenced by busVoltage(), sample(), and vals().

com

std::unique_ptr<duds::hardware::interface::Smbus> duds::hardware::devices::instruments::INA219::com

private

Communication bus.

Definition at line 35 of file INA219.hpp.

Referenced by INA219(), sample(), and ~INA219().

shunt

double duds::hardware::devices::instruments::INA219::shunt

private

Shunt resistance; used to compute current.

Definition at line 39 of file INA219.hpp.

Referenced by maxCurrent(), and shuntResistance().

shuntV

std::int16_t duds::hardware::devices::instruments::INA219::shuntV

private

The raw data for the sampled shunt voltage.

Definition at line 43 of file INA219.hpp.

Referenced by sample(), shuntVoltage(), and vals().

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The documentation for this class was generated from the following files:

• INA219.hpp
• INA219.cpp