Base class for PCx85 LCD segment display drivers. More...

#include <SegDriver_PCx85.h>

Inheritance diagram for SegDriver_PCx85:

Public Types
enum	ModeStatus { MODE_STATUS_BLANK = 0 , MODE_STATUS_ENABLED = 1 }
	Enable/disable display. More...

enum	BlinkFrequency { BLINK_FREQUENCY_OFF = 0 , BLINK_FREQUENCY_1 = 1 , BLINK_FREQUENCY_2 = 2 , BLINK_FREQUENCY_3 = 3 }
	Set blink frequency. More...

enum	BlinkMode { BLINK_MODE_NORMAL = 0 , BLINK_MODE_ALTRAM = 1 }
	Set blink mode. More...

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

Public Member Functions
	SegDriver_PCx85 (TwoWire &i2c, uint8_t address, uint8_t subaddress)
	Constructor for PCx85 segment driver.

virtual void	init () override
	Logical display sections that can be targeted by higher-level rendering logic.

void	bankSelect (uint8_t input, uint8_t output)
	Select bank for input and output.

void	blink (BlinkFrequency blink=BLINK_FREQUENCY_OFF, BlinkMode mode=BLINK_MODE_NORMAL)
	Set blink frequency and mode.

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

void	on () override
	Turn the display on.

void	off () override
	Turn the display off.

void	command (uint8_t command) override
	Send RAW command to 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
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	_setMode (ModeStatus status, ModeDrive drive=MODE_DRIVE_14, ModeBias bias=MODE_BIAS_13)
	Set the mode of the display.

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

void	_writeRam (uint8_t *data, size_t length, uint8_t address=0) override
	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 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.

Static Protected Attributes
static constexpr uint8_t	DEFAULT_PCF85176_I2C_ADDRESS = 0x38

static constexpr uint8_t	DEFAULT_SUBADDRESS = 0x00

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

Private Member Functions
void	_deviceSelect ()
	Select the device for communication.

Private Attributes
TwoWire &	_i2c

uint8_t	_address

uint8_t	_subaddress

ModeDrive	_drive

ModeBias	_bias

Additional Inherited Members
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.

Detailed Description

Base class for PCx85 LCD segment display drivers.

Implementation of the PCF85176 and similar I2C controllers.

Member Enumeration Documentation

◆ BlinkFrequency

enum SegDriver_PCx85::BlinkFrequency

Set blink frequency.

Enumerator
BLINK_FREQUENCY_OFF	No blinking.
BLINK_FREQUENCY_1	Blink at ~2Hz.
BLINK_FREQUENCY_2	Blink at ~1Hz.
BLINK_FREQUENCY_3	Blink at ~0.5Hz.

◆ BlinkMode

enum SegDriver_PCx85::BlinkMode

Set blink mode.

Note: that alternate RAM blink mode is not supported if 1/3 or 1/4 drive mode is used.

Enumerator
BLINK_MODE_NORMAL	Normal blink mode.
BLINK_MODE_ALTRAM	Alternate RAM blink mode.

◆ ModeStatus

enum SegDriver_PCx85::ModeStatus

Enable/disable display.

Enumerator
MODE_STATUS_BLANK	Display is blanked.
MODE_STATUS_ENABLED	Display is enabled.

Constructor & Destructor Documentation

◆ SegDriver_PCx85()

SegDriver_PCx85::SegDriver_PCx85	(	TwoWire &	i2c,
		uint8_t	address,
		uint8_t	subaddress
	)

Constructor for PCx85 segment driver.

Address is selected by SA0 pins on the device. Subaddress is selected by A0 to A2 pins on the device

Parameters

i2c	Reference to the TwoWire object for I2C communication
address	I2C address of the PCx85 device
subaddress	Subaddress for the device

Member Function Documentation

◆ _deviceSelect()

void SegDriver_PCx85::_deviceSelect ( )

private

Select the device for communication.

This method is used to set the device by subaddress. If address during writing overflow one device's address next device is selected. So this is used to select back to this device.

◆ _setMode()

void SegDriver_PCx85::_setMode	(	ModeStatus	status,
		ModeDrive	drive = `MODE_DRIVE_14`,
		ModeBias	bias = `MODE_BIAS_13`
	)

protected

Set the mode of the display.

This method sets the drive and bias modes for the display. It also enables or disables the display based on the status.

Parameters

status	Display status (enabled or blanked)
drive	Drive mode (default is MODE_DRIVE_14)
bias	Bias mode (default is MODE_BIAS_13)

◆ _writeRam() [1/2]

void SegDriver_PCx85::_writeRam	(	uint8_t *	data,
		size_t	length,
		uint8_t	address = `0`
	)

overrideprotectedvirtual

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() [2/2]

void SegDriver_PCx85::_writeRam	(	uint8_t	data,
		uint8_t	address = `0`
	)

overrideprotectedvirtual

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

Parameters

data	Data byte
address	RAM address

Implements SegLCDLib.

◆ bankSelect()

void SegDriver_PCx85::bankSelect	(	uint8_t	input,
		uint8_t	output
	)

Select bank for input and output.

The bank-select command controls where data is written to RAM and where it is displayed from. Valid values for input and output are 0 or 1.

Parameters

input	input bank selection; storage of arriving display data
output	output bank selection; retrieval of LCD display data

◆ blink()

void SegDriver_PCx85::blink	(	BlinkFrequency	blink = `BLINK_FREQUENCY_OFF`,
		BlinkMode	mode = `BLINK_MODE_NORMAL`
	)

Set blink frequency and mode.

Parameters

blink	Blink frequency to set (default is BLINK_FREQUENCY_OFF)
mode	Blink mode to set (default is BLINK_MODE_NORMAL)

◆ clear()

void SegDriver_PCx85::clear ( )

overridevirtual

Clear all visible segments on the display.

Reimplemented from SegLCDLib.

Reimplemented in SegLCD_PCF85176_TempHumidity, and SegLCD_PCF8576_4Seg6SegMaintSegBatUnits.

◆ command()

void SegDriver_PCx85::command ( uint8_t command )

inlineoverridevirtual

Send RAW command to controller.

Parameters

command Raw command byte

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_PCx85::flush	(	uint8_t	startAddr,
		uint8_t	length
	)

overridevirtual

Flush specific range of buffered changes to the display.

Optimized implementation for PCx85 that uses efficient I2C bulk write.

Parameters

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

Reimplemented from SegLCDLib.

◆ init()

void SegDriver_PCx85::init ( )

overridevirtual

Logical display sections that can be targeted by higher-level rendering logic.

Initialize the display driver, clear display and set position to 0,0.

Implements SegLCDLib.

Reimplemented in SegLCD_PCF85176_2Row4DigSigBatPwr, SegLCD_PCF85176_4DR821B, SegLCD_PCF85176_6DigitSignalBatteryProgress, SegLCD_PCF85176_OneDigit, SegLCD_PCF85176_T1T2Lcd, SegLCD_PCF85176_TempHumidity, and SegLCD_PCF8576_4Seg6SegMaintSegBatUnits.

◆ off()

void SegDriver_PCx85::off ( )

overridevirtual

Turn the display off.

Implements SegLCDLib.

◆ on()

void SegDriver_PCx85::on ( )

overridevirtual

Turn the display on.

Implements SegLCDLib.

Field Documentation

◆ _address

uint8_t SegDriver_PCx85::_address

private

◆ _bias

ModeBias SegDriver_PCx85::_bias

private

◆ _drive

ModeDrive SegDriver_PCx85::_drive

private

◆ _i2c

TwoWire& SegDriver_PCx85::_i2c

private

◆ _subaddress

uint8_t SegDriver_PCx85::_subaddress

private

◆ DEFAULT_PCF85176_I2C_ADDRESS

constexpr uint8_t SegDriver_PCx85::DEFAULT_PCF85176_I2C_ADDRESS = 0x38

staticconstexprprotected

◆ DEFAULT_SUBADDRESS

constexpr uint8_t SegDriver_PCx85::DEFAULT_SUBADDRESS = 0x00

staticconstexprprotected

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

src/SegDriver_PCx85.h
src/SegDriver_PCx85.cpp

Public Types

Public Member Functions

Protected Member Functions

Static Protected Attributes

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ BlinkFrequency

◆ BlinkMode

◆ ModeStatus

Constructor & Destructor Documentation

◆ SegDriver_PCx85()

Member Function Documentation

◆ _deviceSelect()

◆ _setMode()

◆ _writeRam() [1/2]

◆ _writeRam() [2/2]

◆ bankSelect()

◆ blink()

◆ clear()

◆ command()

◆ flush() [1/3]

◆ flush() [2/3]

◆ flush() [3/3]

◆ init()

◆ off()

◆ on()

Field Documentation

◆ _address

◆ _bias

◆ _drive

◆ _i2c

◆ _subaddress

◆ DEFAULT_PCF85176_I2C_ADDRESS

◆ DEFAULT_SUBADDRESS