SegDriver_HT1622 Class Reference

HT1622 LCD segment display driver. More...

#include <SegDriver_HT1622.h>

Inheritance diagram for SegDriver_HT1622:

Public Member Functions
	SegDriver_HT1622 (uint8_t chipselect, uint8_t data, uint8_t write, uint8_t read=-1)
	Constructor for HT1622 segment driver.
void	clear () override
	Clear all visible segments on the display.
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 SegDriver_3Wire
	SegDriver_3Wire (uint8_t chipselect, uint8_t data, uint8_t write, uint8_t read=-1)
	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.
Public Member Functions inherited from SegLCDLib
virtual	~SegLCDLib ()
	Virtual destructor to ensure proper cleanup in derived classes.
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 ch)
void	initBacklight (int8_t backlightPin, BacklightMode backlightMode=BACKLIGHT_DIGITAL, bool backlightActiveHigh=true)
	Initialize GPIO 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
void	_writeRam (uint8_t data, uint8_t address=0)
	Override _writeRam to implement HT1622-specific timing requirements.
void	_writeRam (uint8_t *data, size_t length, uint8_t address=0) override
	Write multiple bytes to RAM starting at specified address.
void	_sendBits (uint16_t data, uint8_t bitCount=8) override
	Override _sendBits to implement HT1622-specific timing requirements.
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 row, uint8_t col, bool state)
	Virtual method for setting decimal point.
virtual void	_setColon (uint8_t row, uint8_t col, bool state)
	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.
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.

Additional Inherited Members
Public Types inherited from SegLCDLib
enum	BacklightMode { BACKLIGHT_DIGITAL , BACKLIGHT_PWM }
	Backlight mode for GPIO control. More...
Protected Attributes inherited from SegDriver_3Wire
uint8_t	_wr
	Write clock pin for the display.
uint8_t	_rd
	Read clock pin for the display.
uint8_t	_data
	Data pin for the display.
uint8_t	_cs
	Chip select pin for the display.
uint8_t	_maxAddress
	Maximum address for this controller.
Protected Attributes inherited from SegLCDLib
bool	_autoFlush = true
	Autoflush mode enabled flag (default: true for LCD API 1.0 compatibility).
int8_t	_backlightPin = -1
	Backlight GPIO pin (-1 if disabled)
BacklightMode	_backlightMode = BACKLIGHT_DIGITAL
	Backlight mode (DIGITAL or PWM)
bool	_backlightActiveHigh = true
	Backlight active high flag.
uint8_t	_backlightBrightness = 0
	Cached backlight brightness.
uint8_t	_displayFlags = 0
	LEDC channel for old ESP32 Arduino Core (2.0.x)
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.
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

HT1622 LCD segment display driver.

This driver extends the 3-wire base driver with HT1622-specific features and stricter timing requirements.

Constructor & Destructor Documentation

SegDriver_HT1622()

SegDriver_HT1622::SegDriver_HT1622	(	uint8_t	chipselect,
		uint8_t	data,
		uint8_t	write,
		uint8_t	read = -1
	)

Constructor for HT1622 segment driver.

Parameters

chipselect	Chip select pin for the display
data	Data pin for the display
write	Write clock pin for the display
read	Read clock pin for the display (optional, default is -1)

Member Function Documentation

_sendBits()

void SegDriver_HT1622::_sendBits ( uint16_t  data, uint8_t  bitCount = 8  )

overrideprotectedvirtual

Override _sendBits to implement HT1622-specific timing requirements.

Reimplemented from SegDriver_3Wire.

_writeRam() [1/2]

void SegDriver_HT1622::_writeRam ( uint8_t *  data, size_t  length, uint8_t  address = 0  )

overrideprotectedvirtual

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)

Reimplemented from SegDriver_3Wire.

_writeRam() [2/2]

void SegDriver_HT1622::_writeRam ( uint8_t  data, uint8_t  address = 0  )

protectedvirtual

Override _writeRam to implement HT1622-specific timing requirements.

Reimplemented from SegDriver_3Wire.

clear()

void SegDriver_HT1622::clear ( )

overridevirtual

Clear all visible segments on the display.

Reimplemented from 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_HT1622::flush ( uint8_t  startAddr, uint8_t  length  )

overridevirtual

Flush specific range of buffered changes to the display.

Optimized implementation for HT1622 that loops through each address since the 3-wire protocol doesn't support bulk write.

Parameters

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

Reimplemented from SegLCDLib.

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

• src/SegDriver_HT1622.h
• src/SegDriver_HT1622.cpp