PCF8591 analog-to-digital converter chip (I2C), used to read analog sensors on the Raspberry Pi. More...

#include <PCF8591.h>

Inheritance diagram for RumPi::PCF8591:

Collaboration diagram for RumPi::PCF8591:

Public Member Functions
	PCF8591 (unsigned int pcfBasePinNumber, int pcfI2cAddress, float adcVoltage=3.3f)
	Builds a PCF8591 ADC bound to the given base pin, I2C address, and reference voltage. More...

virtual	~PCF8591 ()
	Destroys the ADC, turning it off first. More...

virtual void	TurnOn () override
	Initializes the PCF8591 for analog reads via wiringPi, reporting success or failure through the AlertManager. More...

virtual void	TurnOff () override
	No-op: the PCF8591 holds no resources that need releasing when turned off. More...

virtual void	ProcessRawValues () override
	No-op: the PCF8591 reads its channels on demand in ReadAnalogValue, so there are no raw values to process. More...

virtual std::string	ToString () const override
	Serializes the chip's base pin (with its channel range) and ADC voltage to a string. More...

virtual int	ReadAnalogValue (int adcIndex=0) override
	Reads a fresh analog value from the given ADC channel, performing a dummy read and settle delay first. More...

unsigned int	GetPCFBasePinNumber () const
	Gets the wiringPi base pin; the chip's four ADC channels are read as base+0..base+3. More...

int	GetPCFI2CAddress () const
	Gets the chip's I2C address. More...

Public Member Functions inherited from RumPi::IAnalogDigitalConverterComponent
virtual	~IAnalogDigitalConverterComponent ()=0
	Pure virtual destructor, making this an abstract interface. More...

virtual int	ReadAnalogValue (int adcIndex=0)=0
	Reads an analog value from the given channel. More...

float	GetADCVoltage () const
	Gets the ADC's reference voltage. More...

int	GetMaxRawValue () const
	Gets the ADC's full-scale raw count (e.g. More...

Public Member Functions inherited from RumPi::BaseComponent
	BaseComponent ()
	Builds a base component with an unknown type and an empty name. More...

virtual	~BaseComponent ()
	Virtual destructor so deleting a component through a BaseComponent* also cleans up the concrete subclass. More...

virtual void	TurnOn ()=0
	Turns the component on (e.g. More...

virtual void	TurnOff ()=0
	Turns the component off. More...

virtual std::string	ToString () const =0
	Serializes the component's current readings to a string (usually JSON). More...

virtual void	ProcessRawValues ()=0
	Reads and processes the component's latest raw values (called once per poll). More...

virtual EComponentType	GetComponentType () const
	Gets the component's type. More...

const std::string &	GetName () const
	Gets the component's unique per-instance name. More...

void	SetName (const std::string &name)
	Sets the component's unique per-instance name. More...

Private Attributes
unsigned int	myPCFBasePinNumber
	The wiringPi base pin; pcf8591Setup maps the four ADC channels to base+0..base+3. More...

int	myPCFI2CAddress
	The chip's I2C address. More...

Additional Inherited Members
Static Public Member Functions inherited from RumPi::BaseComponent
static std::string	ComponentTypeToString (const EComponentType theComponentTypeToConvert)
	Maps an EComponentType to its string name. More...

static EComponentType	StringToComponentType (const std::string &theComponentTypeName)
	Maps a type name back to its EComponentType (the inverse of ComponentTypeToString), so the client can turn the type carried on the wire back into a value it can look an icon up with. More...

Protected Member Functions inherited from RumPi::IAnalogDigitalConverterComponent
	IAnalogDigitalConverterComponent ()
	Initializes the reference voltage and full-scale count to safe 10-bit defaults; concrete ADCs overwrite both in their own constructor, so a subclass that forgets to set them still yields sane (non-garbage) conversions rather than silently wrong volts. More...

Protected Attributes inherited from RumPi::IAnalogDigitalConverterComponent
float	myADCVoltage
	The ADC's reference voltage, used to convert raw readings to volts. More...

int	myMaxRawValue
	The ADC's full-scale raw count (255 for an 8-bit chip, 1023 for a 10-bit chip). More...

Protected Attributes inherited from RumPi::BaseComponent
EComponentType	myComponentType
	The kind of component this is (set by each concrete subclass). More...

std::string	myName
	A unique per-instance name, assigned when the component is added to the manager. More...

Detailed Description

PCF8591 analog-to-digital converter chip (I2C), used to read analog sensors on the Raspberry Pi.

Author: Eddie O'Hagan

Date: 8/13/2026

Constructor & Destructor Documentation

◆ PCF8591()

RumPi::PCF8591::PCF8591	(	unsigned int	pcfBasePinNumber,
		int	pcfI2CAddress,
		float	adcVoltage = `3.3f`
	)

Builds a PCF8591 ADC bound to the given base pin, I2C address, and reference voltage.

pcf8591Setup maps the chip's four ADC channels to consecutive wiringPi pins base+0..base+3, so only the base pin is stored.

Author: Eddie O'Hagan

Date: 8/13/2026

PCF8591 adc(120, 0x48);

RumPi::PCF8591::PCF8591

PCF8591(unsigned int pcfBasePinNumber, int pcfI2cAddress, float adcVoltage=3.3f)

Builds a PCF8591 ADC bound to the given base pin, I2C address, and reference voltage.

Definition: PCF8591.cpp:21

Parameters

[in]	pcfBasePinNumber	The wiringPi base pin; channels are read as base+0..base+3.
[in]	pcfI2CAddress	The chip's I2C address.
[in]	adcVoltage	The ADC reference voltage.

◆ ~PCF8591()

RumPi::PCF8591::~PCF8591 ( )

virtual

Destroys the ADC, turning it off first.

Author: Eddie O'Hagan

Date: 8/13/2026

PCF8591* adc = new PCF8591(120, 0x48);

delete adc;

Member Function Documentation

◆ GetPCFBasePinNumber()

unsigned int RumPi::PCF8591::GetPCFBasePinNumber ( ) const

Gets the wiringPi base pin; the chip's four ADC channels are read as base+0..base+3.

Author: Eddie O'Hagan

Date: 8/13/2026

unsigned int basePin = adc.GetPCFBasePinNumber();

Returns: The chip's base pin.

◆ GetPCFI2CAddress()

int RumPi::PCF8591::GetPCFI2CAddress ( ) const

Gets the chip's I2C address.

Author: Eddie O'Hagan

Date: 8/13/2026

int address = adc.GetPCFI2CAddress();

Returns: The chip's I2C address.

◆ ProcessRawValues()

void RumPi::PCF8591::ProcessRawValues ( )

overridevirtual

No-op: the PCF8591 reads its channels on demand in ReadAnalogValue, so there are no raw values to process.

Author: Eddie O'Hagan

Date: 8/13/2026

adc.ProcessRawValues();

Implements RumPi::BaseComponent.

◆ ReadAnalogValue()

int RumPi::PCF8591::ReadAnalogValue ( int adcIndex = 0 )

overridevirtual

Reads a fresh analog value from the given ADC channel, performing a dummy read and settle delay first.

Author: Eddie O'Hagan

Date: 8/13/2026

int value = adc.ReadAnalogValue(0);

Parameters

[in] adcIndex The ADC channel index (0 to RUMPI_MAX_PCF8591_PINS - 1).

Returns: The analog reading, or -1 if the channel index is out of range.

Implements RumPi::IAnalogDigitalConverterComponent.

◆ ToString()

std::string RumPi::PCF8591::ToString ( ) const

overridevirtual

Serializes the chip's base pin (with its channel range) and ADC voltage to a string.

Author: Eddie O'Hagan

Date: 8/13/2026

std::string data = adc.ToString();

Returns: A multi-line string describing the ADC.

Implements RumPi::BaseComponent.

◆ TurnOff()

void RumPi::PCF8591::TurnOff ( )

overridevirtual

No-op: the PCF8591 holds no resources that need releasing when turned off.

Author: Eddie O'Hagan

Date: 8/13/2026

adc.TurnOff();

Implements RumPi::BaseComponent.

◆ TurnOn()

void RumPi::PCF8591::TurnOn ( )

overridevirtual

Initializes the PCF8591 for analog reads via wiringPi, reporting success or failure through the AlertManager.

Author: Eddie O'Hagan

Date: 8/13/2026

adc.TurnOn();

Implements RumPi::BaseComponent.

Member Data Documentation

◆ myPCFBasePinNumber

unsigned int RumPi::PCF8591::myPCFBasePinNumber

private

The wiringPi base pin; pcf8591Setup maps the four ADC channels to base+0..base+3.

◆ myPCFI2CAddress

int RumPi::PCF8591::myPCFI2CAddress

private

The chip's I2C address.

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

Source/Headers/RumPi/Components/PCF8591.h
Source/Implementations/RumPi/Components/PCF8591.cpp

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ PCF8591()

◆ ~PCF8591()

Member Function Documentation

◆ GetPCFBasePinNumber()

◆ GetPCFI2CAddress()

◆ ProcessRawValues()

◆ ReadAnalogValue()

◆ ToString()

◆ TurnOff()

◆ TurnOn()

Member Data Documentation

◆ myPCFBasePinNumber

◆ myPCFI2CAddress