#include <AH/Hardware/ExtendedInputOutput/MCP23017.hpp>

Detailed Description

template<class WireType>
class MCP23017< WireType >

Class for MCP23017 I²C I/O expanders.

Template Parameters

WireType The type of the I²C driver to use.

Examples: MCP23017.ino.

Definition at line 19 of file MCP23017.hpp.

Inheritance diagram for MCP23017< WireType >:

Collaboration diagram for MCP23017< WireType >:

Enabling and disabling updatables
void	enable ()
	Enable this updatable: insert it into the linked list of instances, so it gets updated automatically. More...

void	disable ()
	Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically. More...

bool	isEnabled () const
	Check if this updatable is enabled. More...

void	moveDown ()
	Move down this element in the list. More...

static void	enable (UpdatableCRTP *element)
	Enable this updatable: insert it into the linked list of instances, so it gets updated automatically. More...

static void	enable (UpdatableCRTP &element)
	Enable this updatable: insert it into the linked list of instances, so it gets updated automatically. More...

static void	enable (U(&array)[N])
	Enable this updatable: insert it into the linked list of instances, so it gets updated automatically. More...

static void	disable (UpdatableCRTP *element)
	Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically. More...

static void	disable (UpdatableCRTP &element)
	Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically. More...

static void	disable (U(&array)[N])
	Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically. More...

Public Member Functions
	MCP23017 (WireType &wire, uint8_t addressOffset=0, pin_t interruptPin=NO_PIN)
	Constructor. More...

void	pinModeBuffered (pin_t pin, PinMode_t mode) override
	Set the mode of a given pin in the software buffer. More...

void	digitalWriteBuffered (pin_t pin, PinStatus_t status) override
	Set the output of a given pin in the software buffer. More...

PinStatus_t	digitalReadBuffered (pin_t pin) override
	Read the state of the given pin from the software buffer. More...

analog_t	analogReadBuffered (pin_t pin) override
	Read the analog value of the given pin from the software buffer. More...

void	analogWriteBuffered (pin_t, analog_t) override
	Write an analog (or PWM) value to the software buffer given pin. More...

void	begin () override
	Initialize the extended IO element. More...

void	updateBufferedOutputs () override
	Write the internal state to the physical outputs. More...

void	updateBufferedInputs () override
	Read the physical state into the input buffers. More...

void	updateBufferedPinModes ()
	Send the new pin modes to the chip after calling `pinModeBuffered`. More...

pin_t	pinA (pin_t p)
	Get the identifier of the given pin in register A. More...

pin_t	pinB (pin_t p)
	Get the identifier of the given pin in register B. More...

Array< pin_t, N >	pins () const
	Get an array containing all pins of the element. More...

virtual void	pinMode (pin_t pin, PinMode_t mode)
	Set the mode of a given pin. More...

virtual void	digitalWrite (pin_t pin, PinStatus_t state)
	Set the output of the given pin to the given state. More...

virtual PinStatus_t	digitalRead (pin_t pin)
	Read the state of the given pin. More...

virtual void	analogWrite (pin_t pin, analog_t val)
	Write an analog (or PWM) value to the given pin. More...

virtual analog_t	analogRead (pin_t pin)
	Read the analog value of the given pin. More...

pin_t	pin (pin_t pin) const
	Get the extended IO pin number of a given physical pin of this extended IO element. More...

pin_t	operator[] (pin_t pin) const
	Get the extended IO pin number of a given physical pin of this extended IO element. More...

pin_t	getLength () const
	Get the number of pins this IO element has. More...

pin_t	getEnd () const
	Get the largest global extended IO pin number that belongs to this extended IO element. More...

pin_t	getStart () const
	Get the smallest global extended IO pin number that belongs to this extended IO element. More...

Static Public Member Functions
static constexpr uint16_t	length ()

static void	beginAll ()
	Initialize all extended IO elements. More...

static void	updateAllBufferedOutputs ()
	Write the internal states to the physical outputs for all extended IO elements. More...

static void	updateAllBufferedInputs ()
	Read the physical state into the input buffers for all extended IO elements. More...

static DoublyLinkedList< ExtendedIOElement > &	getAll ()
	Get the list of all Extended IO elements. More...

Protected Attributes
ExtendedIOElement *	next

ExtendedIOElement *	previous

Static Protected Attributes
static DoublyLinkedList< ExtendedIOElement >	updatables

Private Member Functions
bool	hasInputs () const
	Check if any of the pins are configured as inputs. More...

template<size_t N>
void	writeI2C (const uint8_t(&values)[N])
	Write any data to the MCP23017. More...

template<class... Args>
void	writeI2C (uint8_t addr, Args... values)
	Write any data to the MCP23017. More...

Private Attributes
WireType *	wire

uint8_t	address

pin_t	interruptPin

bool	pinModesDirty = true

BitArray< 16 >	bufferedPinModes

bool	pullupsDirty = true

BitArray< 16 >	bufferedPullups

bool	outputsDirty = true

BitArray< 16 >	bufferedOutputs

BitArray< 16 >	bufferedInputs

const pin_t	start

const pin_t	end

Static Private Attributes
static constexpr uint8_t	I2C_BASE_ADDRESS = 0x20

static pin_t	offset = NUM_DIGITAL_PINS + NUM_ANALOG_INPUTS

Constructor & Destructor Documentation

◆ MCP23017()

MCP23017	(	WireType &	wire,
		uint8_t	addressOffset = `0`,
		pin_t	interruptPin = `NO_PIN`
	)

Constructor.

Parameters

wire	The Wire/I²C interface to use.
addressOffset	A number between 0 and 7 reflecting the state of the I2C address pins of the MCP23017.
interruptPin	The pin connected to the MCP23017 interrupt pin. This doesn't have to be an interrupt pin of the Arduino. The interrupt pin of the MCP23017 is configured as open-drain active-low output, and the interrupt pins of GPIO banks A and B are mirrored/OR'ed together. This means that you only need to connect a single interrupt pin for each MCP23017, and you can connect the interrupt pins of multiple MCP23017s to a single Arduino pin.

Member Function Documentation

◆ pinModeBuffered()

void pinModeBuffered	(	pin_t	pin,
		PinMode_t	mode
	)

overridevirtual

Set the mode of a given pin in the software buffer.

The buffer is written to the ExtIO device when updateBufferedOutputs is called.

Note: This function might not be implemented by all subclasses.
Some extended IO types, such as shift registers, can only be used as outputs.
On others, it might be implemented, but it could impact all pins of the IO element. For example, enabling the internal pull-up resistor on an analog multiplexer affects all pins of the mux.

Parameters

pin	The (zero-based) pin of this IO element.
mode	The mode to set the pin to (e.g. `INPUT`, `OUTPUT` or `INPUT_PULLUP`).

Implements ExtendedIOElement.

◆ digitalWriteBuffered()

void digitalWriteBuffered	(	pin_t	pin,
		PinStatus_t	state
	)

overridevirtual

Set the output of a given pin in the software buffer.

The buffer is written to the ExtIO device when updateBufferedOutputs is called.

Parameters

pin	The (zero-based) pin of this IO element.
state	The new state to set the pin to.

Implements ExtendedIOElement.

◆ digitalReadBuffered()

PinStatus_t digitalReadBuffered ( pin_t pin )

overridevirtual

Read the state of the given pin from the software buffer.

To update the buffer, you have to call updateBufferedInputs first.

Parameters

pin	The (zero-based) pin of this IO element.

Returns: The state of the given pin.

Implements ExtendedIOElement.

◆ analogReadBuffered()

analog_t analogReadBuffered ( pin_t pin )

overridevirtual

Read the analog value of the given pin from the software buffer.

To update the buffer, you have to call updateBufferedInputs first.

Parameters

pin	The (zero-based) pin of this IO element.

Returns: The new analog value of pin.

Implements ExtendedIOElement.

◆ analogWriteBuffered()

void analogWriteBuffered	(	pin_t	pin,
		analog_t	val
	)

overridevirtual

Write an analog (or PWM) value to the software buffer given pin.

The buffer is written to the ExtIO device when updateBufferedOutputs is called.

Parameters

pin	The (zero-based) pin of this IO element.
val	The new analog value to set the pin to.

Implements ExtendedIOElement.

◆ begin()

void begin ( )

overridevirtual

Initialize the extended IO element.

Implements ExtendedIOElement.

Definition at line 80 of file MCP23017.ipp.

◆ updateBufferedOutputs()

void updateBufferedOutputs ( )

overridevirtual

Write the internal state to the physical outputs.

Implements ExtendedIOElement.

Definition at line 97 of file MCP23017.ipp.

◆ updateBufferedInputs()

void updateBufferedInputs ( )

overridevirtual

Read the physical state into the input buffers.

Implements ExtendedIOElement.

Definition at line 108 of file MCP23017.ipp.

◆ updateBufferedPinModes()

void updateBufferedPinModes

Send the new pin modes to the chip after calling pinModeBuffered.

Definition at line 122 of file MCP23017.ipp.

◆ pinA()

pin_t pinA ( pin_t p )

inline

Get the identifier of the given pin in register A.

Parameters

p	Pin number in [0, 7]

Examples: MCP23017.ino.

Definition at line 58 of file MCP23017.hpp.

◆ pinB()

pin_t pinB ( pin_t p )

inline

Get the identifier of the given pin in register B.

Parameters

p	Pin number in [0, 7]

Definition at line 62 of file MCP23017.hpp.

◆ hasInputs()

bool hasInputs

private

Check if any of the pins are configured as inputs.

Definition at line 141 of file MCP23017.ipp.

◆ writeI2C() [1/2]

void writeI2C ( const uint8_t(&) values[N] )

private

Write any data to the MCP23017.

Definition at line 147 of file MCP23017.ipp.

◆ writeI2C() [2/2]

void writeI2C	(	uint8_t	addr,
		Args...	values
	)

private

Write any data to the MCP23017.

Parameters

addr	The address of the register to write to.
values	The values to write.

Definition at line 155 of file MCP23017.ipp.

◆ pins()

Array< pin_t, N > pins ( ) const

inlineinherited

Get an array containing all pins of the element.

Definition at line 27 of file StaticSizeExtendedIOElement.hpp.

◆ length()

static constexpr uint16_t length ( )

inlinestaticconstexprinherited

Definition at line 31 of file StaticSizeExtendedIOElement.hpp.

◆ pinMode()

virtual void pinMode	(	pin_t	pin,
		PinMode_t	mode
	)

inlinevirtualinherited

Set the mode of a given pin.

Note: This function might not be implemented by all subclasses.
Some extended IO types, such as shift registers, can only be used as outputs.
On others, it might be implemented, but it could impact all pins of the IO element. For example, enabling the internal pull-up resistor on an analog multiplexer affects all pins of the mux.

Parameters

pin	The (zero-based) pin of this IO element.
mode	The mode to set the pin to (e.g. `INPUT`, `OUTPUT` or `INPUT_PULLUP`).

Reimplemented in MAX7219< NumChips, SPIDriver >, and ShiftRegisterOutBase< N >.

Definition at line 100 of file ExtendedIOElement.hpp.

◆ digitalWrite()

virtual void digitalWrite	(	pin_t	pin,
		PinStatus_t	state
	)

inlinevirtualinherited

Set the output of the given pin to the given state.

Parameters

pin	The (zero-based) pin of this IO element.
state	The new state to set the pin to.

Reimplemented in MAX7219< NumChips, SPIDriver >, and ShiftRegisterOutBase< N >.

Definition at line 121 of file ExtendedIOElement.hpp.

◆ digitalRead()

virtual PinStatus_t digitalRead ( pin_t pin )

inlinevirtualinherited

Read the state of the given pin.

Parameters

pin	The (zero-based) pin of this IO element.

Returns: The state of the given pin.

Reimplemented in MAX7219< NumChips, SPIDriver >, and ShiftRegisterOutBase< N >.

Definition at line 141 of file ExtendedIOElement.hpp.

◆ analogWrite()

virtual void analogWrite	(	pin_t	pin,
		analog_t	val
	)

inlinevirtualinherited

Write an analog (or PWM) value to the given pin.

Parameters

pin	The (zero-based) pin of this IO element.
val	The new analog value to set the pin to.

Reimplemented in MAX7219< NumChips, SPIDriver >, and ShiftRegisterOutBase< N >.

Definition at line 161 of file ExtendedIOElement.hpp.

◆ analogRead()

virtual analog_t analogRead ( pin_t pin )

inlinevirtualinherited

Read the analog value of the given pin.

Parameters

pin	The (zero-based) pin of this IO element.

Returns: The new analog value of pin.

Reimplemented in MAX7219< NumChips, SPIDriver >, and ShiftRegisterOutBase< N >.

Definition at line 181 of file ExtendedIOElement.hpp.

◆ beginAll()

void beginAll ( )

staticinherited

Initialize all extended IO elements.

Definition at line 20 of file ExtendedIOElement.cpp.

◆ updateAllBufferedOutputs()

void updateAllBufferedOutputs ( )

staticinherited

Write the internal states to the physical outputs for all extended IO elements.

Definition at line 24 of file ExtendedIOElement.cpp.

◆ updateAllBufferedInputs()

void updateAllBufferedInputs ( )

staticinherited

Read the physical state into the input buffers for all extended IO elements.

Definition at line 28 of file ExtendedIOElement.cpp.

◆ pin()

pin_t pin ( pin_t pin ) const

inherited

Get the extended IO pin number of a given physical pin of this extended IO element.

Parameters

pin	The zero-based physical pin number of this IO element.

Returns: The global, unique extended IO pin number for the given pin.

Examples: 1.MAX7219-Blink.ino, 1.SPI-Blink.ino, and 2.BitBang-Blink.ino.

Definition at line 32 of file ExtendedIOElement.cpp.

◆ operator[]()

pin_t operator[] ( pin_t pin ) const

inherited

Get the extended IO pin number of a given physical pin of this extended IO element.

It is alias for ExtendedIOElement::pin.

Parameters

pin	The zero-based physical pin number of this IO element.

Returns: The global, unique extended IO pin number for the given pin.

Definition at line 48 of file ExtendedIOElement.cpp.

◆ getLength()

pin_t getLength ( ) const

inherited

Get the number of pins this IO element has.

Returns: The number of pins this IO element has.

Definition at line 50 of file ExtendedIOElement.cpp.

◆ getEnd()

pin_t getEnd ( ) const

inherited

Get the largest global extended IO pin number that belongs to this extended IO element.

Definition at line 52 of file ExtendedIOElement.cpp.

◆ getStart()

pin_t getStart ( ) const

inherited

Get the smallest global extended IO pin number that belongs to this extended IO element.

Definition at line 54 of file ExtendedIOElement.cpp.

◆ getAll()

DoublyLinkedList< ExtendedIOElement > & getAll ( )

staticinherited

Get the list of all Extended IO elements.

Definition at line 56 of file ExtendedIOElement.cpp.

◆ enable() [1/4]

void enable ( )

inlineinherited

Enable this updatable: insert it into the linked list of instances, so it gets updated automatically.

Definition at line 100 of file Updatable.hpp.

◆ enable() [2/4]

static void enable ( UpdatableCRTP< ExtendedIOElement > * element )

inlinestaticinherited

Enable this updatable: insert it into the linked list of instances, so it gets updated automatically.

Definition at line 129 of file Updatable.hpp.

◆ enable() [3/4]

static void enable ( UpdatableCRTP< ExtendedIOElement > & element )

inlinestaticinherited

Enable this updatable: insert it into the linked list of instances, so it gets updated automatically.

Definition at line 131 of file Updatable.hpp.

◆ enable() [4/4]

static void enable ( U(&) array[N] )

inlinestaticinherited

Enable this updatable: insert it into the linked list of instances, so it gets updated automatically.

Definition at line 134 of file Updatable.hpp.

◆ disable() [1/4]

void disable ( )

inlineinherited

Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically.

Definition at line 110 of file Updatable.hpp.

◆ disable() [2/4]

static void disable ( UpdatableCRTP< ExtendedIOElement > * element )

inlinestaticinherited

Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically.

Definition at line 140 of file Updatable.hpp.

◆ disable() [3/4]

static void disable ( UpdatableCRTP< ExtendedIOElement > & element )

inlinestaticinherited

Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically.

Definition at line 142 of file Updatable.hpp.

◆ disable() [4/4]

static void disable ( U(&) array[N] )

inlinestaticinherited

Disable this updatable: remove it from the linked list of instances, so it no longer gets updated automatically.

Definition at line 145 of file Updatable.hpp.

◆ isEnabled()

bool isEnabled ( ) const

inlineinherited

Check if this updatable is enabled.

Note: Assumes that the updatable is not added to a different linked list by the user.

Definition at line 124 of file Updatable.hpp.

◆ moveDown()

void moveDown ( )

inlineinherited

Move down this element in the list.

Definition at line 151 of file Updatable.hpp.

Member Data Documentation

◆ I2C_BASE_ADDRESS

constexpr uint8_t I2C_BASE_ADDRESS = 0x20

staticconstexprprivate

Definition at line 65 of file MCP23017.hpp.

◆ wire

WireType* wire

private

Definition at line 67 of file MCP23017.hpp.

◆ address

uint8_t address

private

Definition at line 68 of file MCP23017.hpp.

◆ interruptPin

pin_t interruptPin

private

Definition at line 69 of file MCP23017.hpp.

◆ pinModesDirty

bool pinModesDirty = true

private

Definition at line 72 of file MCP23017.hpp.

◆ bufferedPinModes

BitArray<16> bufferedPinModes

private

Definition at line 73 of file MCP23017.hpp.

◆ pullupsDirty

bool pullupsDirty = true

private

Definition at line 74 of file MCP23017.hpp.

◆ bufferedPullups

BitArray<16> bufferedPullups

private

Definition at line 75 of file MCP23017.hpp.

◆ outputsDirty

bool outputsDirty = true

private

Definition at line 76 of file MCP23017.hpp.

◆ bufferedOutputs

BitArray<16> bufferedOutputs

private

Definition at line 77 of file MCP23017.hpp.

◆ bufferedInputs

BitArray<16> bufferedInputs

private

Definition at line 78 of file MCP23017.hpp.

◆ start

const pin_t start

privateinherited

Definition at line 270 of file ExtendedIOElement.hpp.

◆ end

const pin_t end

privateinherited

Definition at line 271 of file ExtendedIOElement.hpp.

◆ offset

pin_t offset = NUM_DIGITAL_PINS + NUM_ANALOG_INPUTS

staticprivateinherited

Definition at line 272 of file ExtendedIOElement.hpp.

◆ updatables

DoublyLinkedList< ExtendedIOElement > updatables

staticprotectedinherited

Definition at line 156 of file Updatable.hpp.

◆ next

ExtendedIOElement * next

protectedinherited

Definition at line 324 of file LinkedList.hpp.

◆ previous

ExtendedIOElement * previous

protectedinherited

Definition at line 325 of file LinkedList.hpp.

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

Detailed Description

Enabling and disabling updatables

Public Member Functions

Static Public Member Functions

Protected Attributes

Static Protected Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Constructor & Destructor Documentation

◆ MCP23017()

Member Function Documentation

◆ pinModeBuffered()

◆ digitalWriteBuffered()

◆ digitalReadBuffered()

◆ analogReadBuffered()

◆ analogWriteBuffered()

◆ begin()

◆ updateBufferedOutputs()

◆ updateBufferedInputs()

◆ updateBufferedPinModes()

◆ pinA()

◆ pinB()

◆ hasInputs()

◆ writeI2C() [1/2]

◆ writeI2C() [2/2]

◆ pins()

◆ length()

◆ pinMode()

◆ digitalWrite()

◆ digitalRead()

◆ analogWrite()

◆ analogRead()

◆ beginAll()

◆ updateAllBufferedOutputs()

◆ updateAllBufferedInputs()

◆ pin()

◆ operator[]()

◆ getLength()

◆ getEnd()

◆ getStart()

◆ getAll()

◆ enable() [1/4]

◆ enable() [2/4]

◆ enable() [3/4]

◆ enable() [4/4]

◆ disable() [1/4]

◆ disable() [2/4]

◆ disable() [3/4]

◆ disable() [4/4]

◆ isEnabled()

◆ moveDown()

Member Data Documentation

◆ I2C_BASE_ADDRESS

◆ wire

◆ address

◆ interruptPin

◆ pinModesDirty

◆ bufferedPinModes

◆ pullupsDirty

◆ bufferedPullups

◆ outputsDirty

◆ bufferedOutputs

◆ bufferedInputs

◆ start

◆ end

◆ offset

◆ updatables

◆ next

◆ previous