HC165ExpanderAdapter Class Reference

Description

An implementation of the GpioExpanderAdapter using 74HC165 shift register(s)

Datasheet: https://www.ti.com/lit/ds/symlink/sn74hc165.pdf

Supports up to 4 cascaded 74HC165 shift registers, returning 32 pin states (read only)

pin 0 is pin H (pin 7 is pin A) on the first 74HC165, pin 8 is a pin H on the second 74HC165, etc

#include <HC165ExpanderAdapter.h>

Inheritance diagram for HC165ExpanderAdapter:

Public Member Functions
	HC165ExpanderAdapter (byte dataPin, byte clockPin, byte shldPin, byte cascadeLength=cascadeDefaultLength)
	Construct a new HC165ExpanderAdapter. More...
void	begin () override
	Initialize the pin expander. More...
void	update () override
	Read the state of pins on the 74HC165 cascade. More...
bool	read (byte pin) override
	Returns the state of a pin on the expander. More...
void	attachPin (byte pin, int mode=INPUT_PULLUP) override
	pinMode not supported by 74HC165 so do nothing More...
Public Member Functions inherited from GpioExpanderAdapter
virtual void	begin ()=0
	Initialize the expander. (Idempotent) More...
virtual void	update ()=0
	Read the state of all pins on the expander. More...
virtual bool	read (byte pin)=0
	Returns the state of a pin on the expander. More...
virtual void	attachPin (byte pin, int mode=INPUT_PULLUP)=0
	Use it to configure individual pin mode, if expander allows it. Not all of them do. More...
void	write (byte pin, bool state)
	Optionally implemented by concrete GpioExpanderAdapters if they support writing to pins. More...
bool	canWrite ()
	Returns true if the concrete GpioExpanderAdapter has implemented the write() method. More...

Constructor & Destructor Documentation

HC165ExpanderAdapter()

HC165ExpanderAdapter::HC165ExpanderAdapter ( byte  dataPin, byte  clockPin, byte  shldPin, byte  cascadeLength = cascadeDefaultLength  )

inline

Construct a new HC165ExpanderAdapter.

Parameters

dataPin	Serial data
clockPin	Used to shift to next bit
shldPin	Shift/Load input
cascadeLength	The number of 74HC165s chained together (1-4, default is 1)

Member Function Documentation

attachPin()

void HC165ExpanderAdapter::attachPin ( byte  pin, int  mode = INPUT_PULLUP  )

inlineoverridevirtual

pinMode not supported by 74HC165 so do nothing

Parameters

pin
mode

Implements GpioExpanderAdapter.

begin()

void HC165ExpanderAdapter::begin ( )

inlineoverridevirtual

Initialize the pin expander.

Implements GpioExpanderAdapter.

read()

bool HC165ExpanderAdapter::read ( byte  pin )

inlineoverridevirtual

Returns the state of a pin on the expander.

Returns

true/HIGH

false/LOW

Implements GpioExpanderAdapter.

update()

void HC165ExpanderAdapter::update ( )

inlineoverridevirtual

Read the state of pins on the 74HC165 cascade.

Implements GpioExpanderAdapter.

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

• src/GpioExpanderAdapter/HC165ExpanderAdapter.h