MCP23017IoAbstraction Class Reference

#include <IoAbstractionWire.h>

Inheritance diagram for MCP23017IoAbstraction:

Public Member Functions
	MCP23017IoAbstraction (uint8_t address, Mcp23xInterruptMode intMode, pinid_t intPinA, pinid_t intPinB, WireType wireImpl=nullptr)
	MCP23017IoAbstraction (uint8_t address, WireType wireImpl=nullptr)
	MCP23017IoAbstraction (uint8_t address, Mcp23xInterruptMode intMode, pinid_t intPinA, WireType wireImpl=nullptr)
void	pinDirection (pinid_t pin, uint8_t mode) override
void	attachInterrupt (pinid_t pin, RawIntHandler intHandler, uint8_t mode) override
bool	runLoop () override
void	setInvertInputPin (pinid_t pin, bool shouldInvert)
void	resetDevice (int resetPin)
Public Member Functions inherited from Standard16BitDevice
void	writeValue (pinid_t pin, uint8_t value) override
uint8_t	readValue (pinid_t pin) override
void	writePort (pinid_t pin, uint8_t port) override
uint8_t	readPort (pinid_t pin) override
void	clearChangeFlags ()
void	setReadPort (int port)
bool	isReadPortSet (int port) const
bool	isWritePortSet (int port) const
bool	isInitNeeded () const
void	markInitialised ()
Public Member Functions inherited from BasicIoAbstraction
uint8_t	digitalRead (pinid_t p)
void	digitalWrite (pinid_t p, uint8_t v)
uint8_t	digitalReadS (pinid_t p)
void	digitalWriteS (pinid_t p, uint8_t v)
void	writePortS (pinid_t p, uint8_t v)
uint8_t	readPortS (pinid_t p)
void	pinMode (pinid_t pin, uint8_t mode)
bool	sync ()

Additional Inherited Members
Protected Attributes inherited from Standard16BitDevice
uint16_t	lastRead
uint16_t	toWrite
uint8_t	flags

Detailed Description

This abstaction supports most of the available features on the 23x17 range of IOExpanders. It supports most of the GPIO functions and nearly all of the interrupt modes, and is therefore very close to Arduino pins in terms of functionality.

Constructor & Destructor Documentation

MCP23017IoAbstraction() [1/3]

MCP23017IoAbstraction::MCP23017IoAbstraction	(	uint8_t	address,
		Mcp23xInterruptMode	intMode,
		pinid_t	intPinA,
		pinid_t	intPinB,
		WireType	wireImpl = nullptr
	)

Most complete constructor, allows for either single or dual interrupt mode and all capabilities

See also

iofrom23017

iofrom23017IntPerPort

MCP23017IoAbstraction() [2/3]

MCP23017IoAbstraction::MCP23017IoAbstraction ( uint8_t  address, WireType  wireImpl = nullptr  )

explicit

Simplest constructor: create a MCP23017 device with no interrupt mode enabled, only the I2C address needed.

Parameters

address

the I2C address

MCP23017IoAbstraction() [3/3]

MCP23017IoAbstraction::MCP23017IoAbstraction	(	uint8_t	address,
		Mcp23xInterruptMode	intMode,
		pinid_t	intPinA,
		WireType	wireImpl = nullptr
	)

Create a MCP23017 device that will use a single interrupt mode and optionally provide the wire implementation

Parameters

address
intPinA

Member Function Documentation

pinDirection()

void MCP23017IoAbstraction::pinDirection ( pinid_t  pin, uint8_t  mode  )

overridevirtual

Sets the pin direction similar to pinMode, pin direction on this device supports INPUT_PULLUP, INPUT and OUTPUT.

Parameters

pin	the pin to set direction for on this device
mode	the mode such as INPUT, INPUT_PULLUP, OUTPUT

Reimplemented from BasicIoAbstraction.

attachInterrupt()

void MCP23017IoAbstraction::attachInterrupt ( pinid_t  pin, RawIntHandler  intHandler, uint8_t  mode  )

overridevirtual

Attaches an interrupt to the device and links it to the arduino pin. On the MCP23017 nearly all interrupt modes are supported, including CHANGE, RISING, FALLING and are selective both per port and by pin.

Reimplemented from BasicIoAbstraction.

runLoop()

bool MCP23017IoAbstraction::runLoop ( )

overridevirtual

updates settings on the board after changes

Reimplemented from BasicIoAbstraction.

setInvertInputPin()

void MCP23017IoAbstraction::setInvertInputPin	(	pinid_t	pin,
		bool	shouldInvert
	)

This MCP23017 only function inverts the meaning of a given input pin. The pins for this are 0..15 and true will invert the meaning, whereas false will leave as is. regardless if you are using any other IO expanders, using this function requires that you have an actual MCP23017IoAbstraction reference. If you want to use this feature, instead of the variable being of type IoAbstractionRef, it should be of type MCP23017IoAbstraction*

Parameters

pin	the input pin between 0..15
shouldInvert	true to invert the given pin, otherwise false.

resetDevice()

void MCP23017IoAbstraction::resetDevice

(

int

resetPin

)

If you've connected the reset pin to a GPIO, then provide the pin to this function and it will reset the device then leave the pin in the right state for the device to function. It will yield to task manager for 100 microseconds. It also ensures that the pin is set as output first.

Parameters

resetPin

the reset GPIO pin.

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

• src/IoAbstractionWire.h
• src/IoAbstractionWire.cpp