Base class for 3-wire serial LCD segment display drivers. More...

#include <SegDriver_3Wire.h>

Inheritance diagram for SegDriver_3Wire:

Public Member Functions
	SegDriver_3Wire (SegTransport3Wire &transport, uint8_t chipselect)
	Constructor for 3-wire serial LCD driver.

void	init () override
	Initialize GPIO pins for communication.

void	on () override
	Turn the display on.

void	off () override
	Turn the display off.

void	command (uint8_t command) override
	Send command to the controller.

void	flush (uint8_t startAddr, uint8_t length) override
	Flush specific range of buffered changes to the display.

virtual void	flush ()
	Flush all buffered changes to the display.

virtual void	flush (uint8_t startAddr, uint8_t length)
	Flush specific range of buffered changes to the display.

Public Member Functions inherited from SegLCDLib
	SegLCDLib ()=default
	Default constructor.

virtual	~SegLCDLib ()
	Virtual destructor to ensure proper cleanup in derived classes.

	SegLCDLib (const SegLCDLib &)=delete
	Disable copying to keep the RAM buffer uniquely owned.

SegLCDLib &	operator= (const SegLCDLib &)=delete

virtual void	clear ()
	Clear all visible segments on the display.

void	home ()
	Set cursor to 0, 0 without clear display.

virtual void	setCursor (uint8_t row, uint8_t col)
	Set cursor on exact digit.

virtual size_t	write (uint8_t)

size_t	write (const char *str)
	Write a null-terminated string to the display.

size_t	write (const char *buffer, size_t size)
	Write a buffer of characters to the display.

void	initBacklight (SegBacklight *backlight, BacklightMode backlightMode=BACKLIGHT_DIGITAL)
	Initialize backlight control.

virtual void	setBacklight (bool state)
	Set backlight state (on/off).

virtual void	setBacklight (int brightness)
	Set backlight brightness (0-255).

void	setAutoFlush (bool enable)
	Enable or disable autoflush mode.

bool	getAutoFlush () const
	Get current autoflush state.

const uint8_t *	getRamBuffer () const
	Get pointer to internal RAM buffer (read-only).

size_t	getRamBufferSize () const
	Get size of internal RAM buffer in bytes.

Protected Member Functions
virtual void	_writeRam (uint8_t *data, size_t length, uint8_t address)
	Write multiple bytes to RAM starting at specified address.

void	_writeRam (uint8_t data, uint8_t address=0)
	Low-level method to write a single byte to display RAM.

virtual void	_writeRam (uint8_t *data, size_t length, uint8_t address)=0
	Low-level method to write a data buffer to display RAM.

Protected Member Functions inherited from SegLCDLib
void	_setFlag (uint8_t mask)
	Set a specific flag bit.

void	_clearFlag (uint8_t mask)
	Clear a specific flag bit.

bool	_isFlagSet (uint8_t mask) const
	Check if a specific flag bit is set.

void	_clearAllFlags ()
	Clear all flags.

bool	_dotWrite (uint8_t ch, int8_t minCol, int8_t maxCol, int8_t ramOffset)
	Write decimal point.

void	_dotClearCur (int8_t minCol, int8_t maxCol)
	Clear current decimal (overwrite).

void	_colonClearIfNotFlagged (uint8_t ch, uint8_t colonCol, uint8_t colonFlag)
	Clear colon if its flag is not set.

virtual void	_setDecimal (uint8_t, uint8_t, bool)
	Virtual method for setting decimal point.

virtual void	_setColon (uint8_t, uint8_t, bool)
	Virtual method for setting colon.

void	_allocateBuffer (size_t size)
	Allocate RAM buffer for display data.

void	_writeRamMasked (uint8_t data, uint8_t address, uint8_t mask=0xFF)
	Write to display RAM with nibble-aware masking support.

void	_writeRam (uint8_t data, uint8_t address=0)
	Low-level method to write a single byte to display RAM.

uint8_t	_get_char_value (char ch)
	Helper method to convert a character to its segment representation.

uint16_t	_get_16char_value (char ch)
	Helper method to convert a character to its 16-segment representation.

Protected Attributes
SegTransport3Wire &	_transport

uint8_t	_cs
	Chip select pin for the display.

Protected Attributes inherited from SegLCDLib
bool	_autoFlush = true
	Autoflush mode enabled flag (default: true for LCD API 1.0 compatibility).

SegBacklight *	_backlight = nullptr
	Backlight implementation (nullptr if disabled)

BacklightMode	_backlightMode = BACKLIGHT_DIGITAL
	Backlight mode (DIGITAL or PWM)

uint8_t	_backlightBrightness = 0
	Cached backlight brightness.

uint8_t	_displayFlags = 0
	Generic flag storage for display-specific state tracking.

uint8_t *	_ramBuffer = nullptr
	Dynamic RAM buffer for display data (allocated by derived classes).

size_t	_ramBufferSize = 0
	Size of allocated RAM buffer in bytes.

uint8_t	_cursorRow = 0
	Current Row.

uint8_t	_cursorCol = 0
	Current Column.

Additional Inherited Members
Public Types inherited from SegLCDLib
enum	BacklightMode { BACKLIGHT_DIGITAL , BACKLIGHT_PWM }
	Backlight mode for GPIO control. More...

Static Protected Attributes inherited from SegLCDLib
static constexpr uint8_t	FLAG_PENDING_DOT = 0x80
	Common flag for decimal handling when RAM offset is 0.

Detailed Description

Base class for 3-wire serial LCD segment display drivers.

This class implements the common 3-wire serial communication protocol used by controllers like HT1621, VK0192, and HT1622.

Constructor & Destructor Documentation

◆ SegDriver_3Wire()

SegDriver_3Wire::SegDriver_3Wire	(	SegTransport3Wire &	transport,
		uint8_t	chipselect
	)

Constructor for 3-wire serial LCD driver.

Parameters

transport	3-wire transport implementation
chipselect	Chip select pin

Member Function Documentation

◆ _writeRam() [1/3]

void SegDriver_3Wire::_writeRam	(	uint8_t *	data,
		size_t	length,
		uint8_t	address
	)

protectedvirtual

Write multiple bytes to RAM starting at specified address.

Parameters

data	Pointer to data array
length	Number of bytes to write
address	Starting RAM address (0-based)

Implements SegLCDLib.

◆ _writeRam() [2/3]

virtual void SegLCDLib::_writeRam	(	uint8_t *	data,
		size_t	length,
		uint8_t	address
	)

protectedvirtual

Low-level method to write a data buffer to display RAM.

Parameters

data	Pointer to data buffer
length	Length of data buffer
address	Start RAM address

Implements SegLCDLib.

◆ _writeRam() [3/3]

void SegLCDLib::_writeRam	(	uint8_t	data,
		uint8_t	address = `0`
	)

protected

Low-level method to write a single byte to display RAM.

Parameters

data	Data byte
address	RAM address

◆ command()

void SegDriver_3Wire::command ( uint8_t command )

overridevirtual

Send command to the controller.

Parameters

command Command byte to send

Implements SegLCDLib.

◆ flush() [1/3]

void SegLCDLib::flush ( )

virtual

Flush all buffered changes to the display.

Writes the entire display buffer to the hardware. This is useful when autoflush is disabled to batch multiple write() calls into a single hardware update cycle.

Safe to call even when autoflush is enabled (no effect).

See also: setAutoFlush()

Reimplemented from SegLCDLib.

◆ flush() [2/3]

void SegLCDLib::flush	(	uint8_t	startAddr,
		uint8_t	length
	)

virtual

Flush specific range of buffered changes to the display.

Writes a specific address range from the display buffer to hardware. This is an advanced API for optimizing updates when only part of the display needs to be refreshed.

For example, to update only the first row of a multi-row display:

lcd.flush(0, 6); // Update first 6 bytes (row 0)

Safe to call even when autoflush is enabled (no effect).

Parameters

startAddr	Starting buffer address in bytes (RAM buffer index)
length	Number of bytes to flush

See also: setAutoFlush()

Reimplemented from SegLCDLib.

◆ flush() [3/3]

void SegDriver_3Wire::flush	(	uint8_t	startAddr,
		uint8_t	length
	)

overridevirtual

Flush specific range of buffered changes to the display.

The 3-wire protocol has no bulk write support, so this writes each address in the range individually.

Parameters

startAddr	Starting buffer address in bytes (RAM buffer index)
length	Number of bytes to flush

Reimplemented from SegLCDLib.

◆ init()

void SegDriver_3Wire::init ( )

overridevirtual

Initialize GPIO pins for communication.

Reimplemented from SegLCDLib.

Reimplemented in SegLCD_HT1621_4SegDegree, SegLCD_HT1621_6SegBat, SegLCD_HT1621_LCM0844, SegLCD_HT1621_LCM59011, SegLCD_HT1621_LCM88128, SegLCD_HT1622_10Dig16Seg, and SegLCD_VK0192_5DigSigBattProgress.

◆ off()

void SegDriver_3Wire::off ( )

overridevirtual

Turn the display off.

Implements SegLCDLib.

◆ on()

void SegDriver_3Wire::on ( )

overridevirtual

Turn the display on.

Implements SegLCDLib.

Field Documentation

◆ _cs

uint8_t SegDriver_3Wire::_cs

protected

Chip select pin for the display.

◆ _transport

SegTransport3Wire& SegDriver_3Wire::_transport

protected

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

src/SegDriver_3Wire.h
src/SegDriver_3Wire.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SegDriver_3Wire()

Member Function Documentation

◆ _writeRam() [1/3]

◆ _writeRam() [2/3]

◆ _writeRam() [3/3]

◆ command()

◆ flush() [1/3]

◆ flush() [2/3]

◆ flush() [3/3]

◆ init()

◆ off()

◆ on()

Field Documentation

◆ _cs

◆ _transport