Concrete driver for the XL9555 16‑bit I2C GPIO expander. More...

#include <IoExpanderXL9555.hpp>

Inheritance diagram for IoExpanderXL9555:

Public Types
enum	Port { PORT0 = 0x00FF , PORT1 = 0xFF00 , PORT_ALL = 0xFFFF }

enum	IoExpanderGPIO { __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) , __attribute__ =((deprecated("Use integer pin numbers (0-15) directly instead."))) }

Public Member Functions
	IoExpanderXL9555 ()
	Construct a new IoExpanderXL9555 object.

	~IoExpanderXL9555 ()=default
	Destroy the IoExpanderXL9555 object.

void	digitalWritePort (uint16_t mask, uint16_t values) override
	Write to multiple pins simultaneously using a mask.

uint16_t	digitalReadPort () override
	Read the values of all 16 input pins as a single 16-bit word.

Public Member Functions inherited from IoExpanderBase
	IoExpanderBase (uint8_t pinCount)
	Construct a new IoExpanderBase object.

virtual	~IoExpanderBase ()=default
	Virtual destructor.

virtual void	deinit ()
	Deinitialize the expander.

void	configPins (uint16_t pinMask, uint8_t mode)
	Configure multiple pins as input or output simultaneously.

void	pinMode (uint8_t pin, uint8_t mode)
	Set the direction of a GPIO pin.

void	digitalWrite (uint8_t pin, bool value)
	Write a digital value to an output pin.

bool	digitalRead (uint8_t pin)
	Read the digital value from an input pin.

void	digitalToggle (uint8_t pin)
	Toggle the state of an output pin.

uint8_t	pinCount () const
	Get the total number of pins provided by this expander.

uint16_t	pinToMask (uint8_t pin) const
	Convert a pin number to its corresponding bitmask.

Public Member Functions inherited from I2CDeviceNoHal
bool	begin (SensorCommCustom::CustomCallback callback, uint8_t addr)
	Initialize the sensor using custom callback interface.

Public Member Functions inherited from DeviceBeginCommon
virtual	~DeviceBeginCommon ()

uint8_t	getAddress () const

uint8_t	getInterface () const

Public Member Functions inherited from SensorCommWrapper
	SensorCommWrapper ()=default

int	readReg (uint8_t reg) const

int	readRegBuff (uint8_t reg, uint8_t *buf, size_t len) const

int	readBuff (uint8_t *buf, size_t len) const

int	writeReg (uint8_t reg, uint8_t val)

int	writeRegBuff (uint8_t reg, uint8_t *buf, size_t len)

int	writeBuff (uint8_t *buf, size_t len)

int	writeThenRead (const uint8_t write_buffer, size_t write_len, uint8_t read_buffer, size_t read_len)

bool	setRegBit (uint8_t reg, uint8_t bit)

bool	clrRegBit (uint8_t reg, uint8_t bit)

bool	getRegBit (uint8_t reg, uint8_t bit)

int	updateBits (uint8_t reg, uint8_t mask, uint8_t value_shifted)

void	setAddress (uint8_t address)

void	setAck (bool enable)

Public Member Functions inherited from SensorCommInterface
virtual	~SensorCommInterface ()=default

Protected Member Functions
void	pinModeImpl (uint8_t pin, uint8_t mode) override
	Set the direction of a single pin.

void	configPinsImpl (uint16_t pinMask, uint8_t mode) override
	Hardware‑specific implementation for configuring multiple pins simultaneously.

void	digitalWriteImpl (uint8_t pin, bool value) override
	Write a digital value to an output pin.

bool	digitalReadImpl (uint8_t pin) override
	Read the digital value from an input pin.

bool	initImpl (uint8_t param) override
	Perform chip‑specific initialization.

Protected Member Functions inherited from DeviceBeginCommon
	DeviceBeginCommon ()=default

virtual bool	ensureValid () const override

virtual SensorCommBase *	getComm () const override

virtual void	beforeBegin ()

virtual void	afterCommReady ()

virtual void	afterInitSuccess (uint8_t param)

virtual void	onBeginFail ()

bool	fail ()

void	clearCommState ()

template<typename CreateComm >
bool	beginLifecycle (uint8_t addr, uint8_t iface, uint8_t initParam, CreateComm createComm)

Additional Inherited Members
Protected Attributes inherited from IoExpanderBase
uint8_t	_pinCount
	Number of GPIO pins.

std::unique_ptr< uint8_t[]>	_pinModes
	Cached pin modes (INPUT/OUTPUT)

std::unique_ptr< bool[]>	_outputStates
	Cached output states (true = HIGH)

Protected Attributes inherited from DeviceBeginCommon
std::unique_ptr< SensorCommBase >	comm

std::unique_ptr< SensorHal >	hal

std::unique_ptr< SensorCommStatic >	staticComm

uint8_t	_addr = 0

uint8_t	_iface = COMM_CUSTOM

Detailed Description

Concrete driver for the XL9555 16‑bit I2C GPIO expander.

The XL9555 provides 16 bidirectional I/O pins, organized as two 8‑bit ports. This class implements the hardware‑specific operations required by the IoExpanderBase interface using I2C communication.

Definition at line 97 of file expander/IoExpanderXL9555.hpp.

Member Enumeration Documentation

◆ IoExpanderGPIO

enum IoExpanderXL9555::IoExpanderGPIO

Enumerator
__attribute__
__attribute__
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__attribute__

Definition at line 106 of file expander/IoExpanderXL9555.hpp.

◆ Port

enum IoExpanderXL9555::Port

Enumerator
PORT0
PORT1
PORT_ALL

Definition at line 100 of file expander/IoExpanderXL9555.hpp.

Constructor & Destructor Documentation

◆ IoExpanderXL9555()

IoExpanderXL9555::IoExpanderXL9555 ( )

inline

Construct a new IoExpanderXL9555 object.

Initializes the base class with the fixed pin count of 16.

Definition at line 130 of file expander/IoExpanderXL9555.hpp.

◆ ~IoExpanderXL9555()

IoExpanderXL9555::~IoExpanderXL9555 ( )

default

Destroy the IoExpanderXL9555 object.

Member Function Documentation

◆ configPinsImpl()

void IoExpanderXL9555::configPinsImpl	(	uint16_t	pinMask,
		uint8_t	mode
	)

inlineoverrideprotectedvirtual

Hardware‑specific implementation for configuring multiple pins simultaneously.

This function modifies the configuration registers (CFG0/CFG1) of the XL9555. It reads the current register values, updates only the bits specified in pinMask, and writes the new values back. This ensures that the direction of pins not listed in the mask remains unchanged.

After updating the hardware, the internal pin mode cache (_pinModes) is also updated for consistency, so that subsequent individual pin operations see the correct cached state.

Parameters

pinMask	Bitmask of pins to configure. Bits 0‑7 correspond to Port 0 (pins 0‑7), bits 8‑15 correspond to Port 1 (pins 8‑15).
mode	Desired mode: INPUT or OUTPUT.

Note: This function assumes that comm and _pinModes are valid (they are checked in the base class configPins() before calling here).

Implements IoExpanderBase.

Definition at line 232 of file expander/IoExpanderXL9555.hpp.

References IoExpanderBase::_pinModes, i, SensorCommWrapper::readReg(), and SensorCommWrapper::writeReg().

◆ digitalReadImpl()

bool IoExpanderXL9555::digitalReadImpl ( uint8_t pin )

inlineoverrideprotectedvirtual

Read the digital value from an input pin.

Reads the input register (INP0 for pins 0‑7, INP1 for pins 8‑15).

Parameters

pin	Pin number (0‑15).

Returns: true Pin is HIGH.; false Pin is LOW.

Implements IoExpanderBase.

Definition at line 310 of file expander/IoExpanderXL9555.hpp.

References DeviceBeginCommon::ensureValid(), SensorCommWrapper::readReg(), and SENSORLIB_LOG_E.

◆ digitalReadPort()

uint16_t IoExpanderXL9555::digitalReadPort ( )

inlineoverridevirtual

Read the values of all 16 input pins as a single 16-bit word.

Reads both input registers (INP0 and INP1) and combines them into a 16-bit value where the lower 8 bits correspond to Port 0 (pins 0‑7) and the upper 8 bits correspond to Port 1 (pins 8‑15).

Returns: uint16_t Bitmask of all input pin states. Bit 0 is pin 0, bit 15 is pin 15. Returns 0 and logs an error if the expander is not initialized.

Reimplemented from IoExpanderBase.

Definition at line 177 of file expander/IoExpanderXL9555.hpp.

References SensorCommWrapper::readReg().

Referenced by loop().

◆ digitalWriteImpl()

void IoExpanderXL9555::digitalWriteImpl	(	uint8_t	pin,
		bool	value
	)

inlineoverrideprotectedvirtual

Write a digital value to an output pin.

Updates the output register (OUTP0 for pins 0‑7, OUTP1 for pins 8‑15) accordingly.

Parameters

pin	Pin number (0‑15).
value	true for HIGH, false for LOW.

Implements IoExpanderBase.

Definition at line 286 of file expander/IoExpanderXL9555.hpp.

References SensorCommWrapper::clrRegBit(), SENSORLIB_LOG_E, and SensorCommWrapper::setRegBit().

◆ digitalWritePort()

void IoExpanderXL9555::digitalWritePort	(	uint16_t	mask,
		uint16_t	values
	)

inlineoverridevirtual

Write to multiple pins simultaneously using a mask.

This override writes whole output registers when the mask covers an entire port, and updates the internal output state cache.

Parameters

mask	Bitmask where a 1 indicates the pin should be updated.
values	Bitmask of the new values for the selected pins.

Reimplemented from IoExpanderBase.

Definition at line 146 of file expander/IoExpanderXL9555.hpp.

References IoExpanderBase::_outputStates, i, SENSORLIB_LOG_E, and SensorCommWrapper::writeReg().

Referenced by loop().

◆ initImpl()

bool IoExpanderXL9555::initImpl ( uint8_t param )

inlineoverrideprotectedvirtual

Perform chip‑specific initialization.

If the provided address is XL9555_UNKNOWN_ADDRESS, this function attempts to auto‑discover the device by scanning the standard XL9555 I2C addresses (0x20‑0x27). Otherwise, it verifies communication by reading the input port 0 register.

Parameters

param I2C device address, or XL9555_UNKNOWN_ADDRESS for auto‑discovery.

Returns: true Initialization successful.; false Initialization failed (device not found or communication error).

Implements IoExpanderBase.

Definition at line 337 of file expander/IoExpanderXL9555.hpp.

References SensorCommWrapper::readReg(), SENSORLIB_LOG_D, SENSORLIB_LOG_E, and SensorCommWrapper::setAddress().

◆ pinModeImpl()

void IoExpanderXL9555::pinModeImpl	(	uint8_t	pin,
		uint8_t	mode
	)

inlineoverrideprotectedvirtual

Set the direction of a single pin.

This function configures the corresponding bit in the configuration register (CFG0 for pins 0‑7, CFG1 for pins 8‑15). A 0 in the configuration register means output, a 1 means input.

Parameters