The main class for the LcdDriver, all interactions with the 1602 lcd controller will be through this class. More...

#include <lcd_driver.hpp>

Collaboration diagram for lcddriver::LcdDriver:

Public Member Functions
	LcdDriver (const LcdConfig &lcdConfig)
	Construct a new Lcd Driver object, doesn't initiate any hardware, just compute data to be ready for future operations. More...

void	init (void)
	Initialize the lcd driver, by turning on all gpio clocks and set the gpio mode to be ready to drive the lcd.

void	enable (void)
	Start communicating with the lcd and write settings to the lcd controller, this might take more than other operations since it will wait the recommended amount of time in the manual for the lcd to warm up.

void	displayWrite (const char *dataToWrite)
	Erase the display and add new text to it starting at position (0,0), this method will be the one used the most as it offers the most straightforward interface to writing to the LCD. More...

void	displayAppend (const char *dataToAppend)
	Append text to existing text onscreen, this method will also be used the most if there is no need to modify the deeper level API Note that during other operation, the cursor might have been moved, if that happens, it's best to use the cursorPositionChange to get back to the desired position and continue printing text. More...

void	newCustomCharAdd (const uint8_t charPattern[CUSTOM_CHAR_PATTERN_LEN], const uint32_t &customCharSlot)
	Add new custom character pattern The new pattern will be stored in the custom generator RAM of the lcd controller, the 1602 can store 8 5x8 or 4 5x10 pattern. More...

void	lcdSettingSwitch (const bool &displayOn, const bool &cursorOn, const bool &cursorBlinkOn)
	Change lcd settings like on/off display, cursor, or blinking mode This method writes to the lcd controller register to set the settings. More...

void	lcdReset (void)
	reset the LCD and erase all RAM, also reset cursor to (0,0)

void	cursorPositionChange (const uint8_t &cursorX, const uint8_t &cursorY)
	Change cursor position on an x-y scale This method also changes the data ram position with the cursor so future texts will be printed at the cursor. More...

void	backLedSwitch (const bool &isBackLedOn)
	Turn on or off the back light LED The TivaC itself probably doesn't have the current to turn on or off the backLight alone so probably use a relay or a transistor. More...

Private Member Functions
void	parallelDataRead (const bool &isDataReg, uint8_t *readDataBuf, const uint32_t &totalReadData)
	used for reading the data from the controller RAM/program memory The method will follow procedures outlined in the datasheet to intiate and read data from the controller, if using 4 pins it will take two transfers to deliver 8 bits instead of 1 if using 8 pins More...

void	parallelDataWrite (const uint8_t *dataList, const uint32_t &dataLen, const bool &isDataReg)
	used for sending data to the data pins(D0-D7) connected to the LCD The bits are shifted to each pin and then a proper setup and hold time is followed to make sure that the controller receives the data, the method will follow the correct procedure to intitiate connection with the controller More...

void	parallelDataWriteSingle (const uint8_t &data, const bool &isDataReg)
	used for writing a single byte to the lcd controller More...

void	parallelModeSwitch (const bool &isInput)
	switch all the data pins(like D0-D7) to input mode or output mode Used for quickly switching between receiving and sending data More...

void	pinModeSwitch (const uint32_t pinDesc[PIN_DESCRIPTION_LEN], const bool &isInput)
	switch a single pin to input/output More...

void	pinWrite (const uint32_t pinDesc[PIN_DESCRIPTION_LEN], const bool &output)
	switch on/off a pin This is the lowest level function, used for toggling control pin for bitbanging during communcication More...

bool	pinRead (const uint32_t pinDesc[PIN_DESCRIPTION_LEN])
	Read whehther a pin is high or low. More...

void	pinPadConfig (const uint32_t pinDesc[PIN_DESCRIPTION_LEN])
	configure the pins on things like drive strength(affect rise/fall time of signal), push/pull mode More...

void	pinDescCheck (uint32_t pinDesc[PIN_DESCRIPTION_LEN])
	check whether the array describing a pin is valid, will raise assert if not More...

void	comSetup (const bool &isDataReg, const bool &isReadMode)
	Utility function used to generate signal to start the communication with the lcd controller The method will put the RS, RW line in the correct mode(depending on other params passed to this function), pull high enable pin and then wait for the signal to become stable then exit. More...

void	comStop (void)
	stop the communcation by waiting for the current data to be finished transacting and then deassert the enable line

void	comMaintain (const bool &isReadMode)
	temporarily deassert the enable line, wait for the current data to be finished transacting and then asser the enable line again to continue communication More...

void	registerSelect (const bool &isDataReg)
	select data(like RAM) or program register be switching the RS line More...

void	configWrite (void)
	used for writing configs to controller, uses other functions like functionSetCommandCreate to get the command then push it to the lcd controller

void	comSwitch (const bool &iscomEnabled)
	turn on or off communication by switching the EN pin More...

void	comModeSwitch (const bool &isReadMode)
	switch to read/write mode by switching RW pin More...

uint8_t	entryModeCommandCreate (const bool &cursorRightDir, const bool &displayShiftEnabled)
	Create a command of entry mode category. More...

uint8_t	displayCommandCreate (const bool &displayOn, const bool &cursorOn, const bool &isCursorBlink)
	Create a command of display category. More...

uint8_t	functionSetCommandCreate (const bool &is8BitDataLen, const bool &is2Lines, const bool &is5x10Font)
	Create a command of function set category. More...

uint8_t	cursorDisplayShiftCommandCreate (const bool &isShiftDisplay, const bool &isRight)
	create a command to shift the cursor and maybe the display with it More...

bool	lcdIsBusy (void)
	Read lcd controller memory and see if the lcd is busy with an operation. More...

uint8_t	addrCounterGet (void)
	Read lcd controller memory to retrieve the 7 bits address counter This command can be helpful during debug to probe what memories are being read. More...

void	addrCounterChange (const uint8_t &addr, const bool &isDataRam)
	Change the address counter on the lcd controller This command is used a lot since it changes the address counter to be ready for the read/write operation. More...

void	dataWrite4Bit (const uint32_t &dataToWrite, const bool &stopAfterWrite)
	Used to write only 4 bits using D4-D7 This command is used mainly during the beginning of the communication where all data is sent using 4 pins only once instead of 4 pins twice like the rest of the communication. More...

uint8_t	instructionDataRead (void)
	Read the lcd controller data to get the busy status and current address counter. More...

void	ramDataWrite (const uint8_t *data, const uint32_t dataLen, const bool &isTextMode)
	Write to the RAM of the lcd controller, can be data ram or character generator RAM. More...

void	ramDataRead (uint8_t *returnData, const uint32_t &totalDataRead, const uint8_t &startingRamAddr, const bool &isDataRam)
	Used for reading the RAM of the lcd controller, it can either be the data ram storing data to be displayed or the character generator ram, storing custom pattern The reading operation may result in the cursor moving. More...

Private Attributes
uint32_t	_totalBitPerPin
	How many bits that each pin has to send, if using 8 then each only has to send 1, but if 4 then each has to do 2.

LcdConfig	_lcdConfig
	The LcdDriver copy of the user config received at constructor.

GeneralTimer	_generalTimer
	Instance of general timer used for all timing purposes.

Detailed Description

The main class for the LcdDriver, all interactions with the 1602 lcd controller will be through this class.

Constructor & Destructor Documentation

lcddriver::LcdDriver::LcdDriver ( const LcdConfig & lcdConfig )

Construct a new Lcd Driver object, doesn't initiate any hardware, just compute data to be ready for future operations.

Parameters

lcdConfig struct storing settings for lcd driver such as pin allocations

Member Function Documentation

void lcddriver::LcdDriver::addrCounterChange	(	const uint8_t &	addr,
		const bool &	isDataRam
	)

private

Change the address counter on the lcd controller This command is used a lot since it changes the address counter to be ready for the read/write operation.

Parameters

addr	address to change to
isDataRam	if true then the address to change to is part of the dataRAM, otherwise part of CGRAM

uint8_t lcddriver::LcdDriver::addrCounterGet ( void )

private

Read lcd controller memory to retrieve the 7 bits address counter This command can be helpful during debug to probe what memories are being read.

Returns: uint8_t the 7 bits address counter

void lcddriver::LcdDriver::backLedSwitch ( const bool & isBackLedOn )

Turn on or off the back light LED The TivaC itself probably doesn't have the current to turn on or off the backLight alone so probably use a relay or a transistor.

Parameters

isBackLedOn turn on LED if true, off otherwise

void lcddriver::LcdDriver::comMaintain ( const bool & isReadMode )

private

temporarily deassert the enable line, wait for the current data to be finished transacting and then asser the enable line again to continue communication

Parameters

isReadMode is this transaction a read one

void lcddriver::LcdDriver::comModeSwitch ( const bool & isReadMode )

private

switch to read/write mode by switching RW pin

Parameters

isReadMode if true then RW is pulled high to indicate the next transaction to be a read one

void lcddriver::LcdDriver::comSetup	(	const bool &	isDataReg,
		const bool &	isReadMode
	)

private

Utility function used to generate signal to start the communication with the lcd controller The method will put the RS, RW line in the correct mode(depending on other params passed to this function), pull high enable pin and then wait for the signal to become stable then exit.

Parameters

isDataReg	true if the target of the communication is the data section of the lcd controller(like DDRAM)
isReadMode	if true then the transaction is a read one

void lcddriver::LcdDriver::comSwitch ( const bool & iscomEnabled )

private

turn on or off communication by switching the EN pin

Parameters

iscomEnabled true then EN pin pulled high, pulled low otherwise

uint8_t lcddriver::LcdDriver::cursorDisplayShiftCommandCreate	(	const bool &	isShiftDisplay,
		const bool &	isRight
	)

private

create a command to shift the cursor and maybe the display with it

Parameters

isShiftDisplay	if true allow display to shift if required
isRight	if true, set the movement direction to right

Returns: uint8_t a command that can be sent to the lcd controller to control cursor movement

void lcddriver::LcdDriver::cursorPositionChange	(	const uint8_t &	cursorX,
		const uint8_t &	cursorY
	)

Change cursor position on an x-y scale This method also changes the data ram position with the cursor so future texts will be printed at the cursor.

Parameters

cursorX	x coordinate to set, max at 15 for 16x2 lcd
cursorY	y coordinate to set, max at 1 for 16x2 lcd

void lcddriver::LcdDriver::dataWrite4Bit	(	const uint32_t &	dataToWrite,
		const bool &	stopAfterWrite
	)

private

Used to write only 4 bits using D4-D7 This command is used mainly during the beginning of the communication where all data is sent using 4 pins only once instead of 4 pins twice like the rest of the communication.

Parameters

dataToWrite	data to be written, most likely a command to setup communication
stopAfterWrite	if true terminate connection after write, otherwise maintain the connection with the lcd controller

void lcddriver::LcdDriver::displayAppend ( const char * dataToAppend )

Append text to existing text onscreen, this method will also be used the most if there is no need to modify the deeper level API Note that during other operation, the cursor might have been moved, if that happens, it's best to use the cursorPositionChange to get back to the desired position and continue printing text.

Parameters

dataToAppend character array reprenting string to print, limited at 32

uint8_t lcddriver::LcdDriver::displayCommandCreate	(	const bool &	displayOn,
		const bool &	cursorOn,
		const bool &	isCursorBlink
	)

private

Create a command of display category.

Parameters

displayOn	if true, turn on display, otherwise off
cursorOn	if true, turn on cursor, otherwise off
isCursorBlink	if true, blink cursor, otherwise no blink

Returns: uint8_t a display command that can be sent to the lcd controller

void lcddriver::LcdDriver::displayWrite ( const char * dataToWrite )

Erase the display and add new text to it starting at position (0,0), this method will be the one used the most as it offers the most straightforward interface to writing to the LCD.

Parameters

dataToWrite character array reprenting string to print, limited at 32

uint8_t lcddriver::LcdDriver::entryModeCommandCreate	(	const bool &	cursorRightDir,
		const bool &	displayShiftEnabled
	)

private

Create a command of entry mode category.

Parameters

cursorRightDir	if true, set the direction of movement to the right
displayShiftEnabled	if true, allow the display to be shifted when necessary(check the manual for this)

Returns: uint8_t an entry command that can be sent to the lcd controller

uint8_t lcddriver::LcdDriver::functionSetCommandCreate	(	const bool &	is8BitDataLen,
		const bool &	is2Lines,
		const bool &	is5x10Font
	)

private

Create a command of function set category.

Parameters

is8BitDataLen	if true, then send data over 8 pins, otherwise, send data using 4 pins(D4-D7)
is2Lines	if true, display 2 lines on lcd, display 1 otherwise
is5x10Font	if true, use 5x10 font, use 5x8 font otherwise

Returns: uint8_t a function set command that can be sent to the lcd controller

uint8_t lcddriver::LcdDriver::instructionDataRead ( void )

private

Read the lcd controller data to get the busy status and current address counter.

Returns: uint8_t the busy bit(bit 7) and the address counter(bit 0-6)

bool lcddriver::LcdDriver::lcdIsBusy ( void )

private

Read lcd controller memory and see if the lcd is busy with an operation.

Returns: true lcd is doing an operation; false lcd is idle

void lcddriver::LcdDriver::lcdSettingSwitch	(	const bool &	displayOn,
		const bool &	cursorOn,
		const bool &	cursorBlinkOn
	)

Change lcd settings like on/off display, cursor, or blinking mode This method writes to the lcd controller register to set the settings.

Parameters

displayOn	display on if true, off otherwise
cursorOn	cursor on if true, off otherwise
cursorBlinkOn	cursor blinking on if true, off otherwise

void lcddriver::LcdDriver::newCustomCharAdd	(	const uint8_t	charPattern[CUSTOM_CHAR_PATTERN_LEN],
		const uint32_t &	customCharSlot
	)

Add new custom character pattern The new pattern will be stored in the custom generator RAM of the lcd controller, the 1602 can store 8 5x8 or 4 5x10 pattern.

Parameters

charPattern	array storing the byte patterns, generate them using the link in the README
customCharSlot	what slot to store the new pattern at, there should be 8 slot if 5x8 font is used

void lcddriver::LcdDriver::parallelDataRead	(	const bool &	isDataReg,
		uint8_t *	readDataBuf,
		const uint32_t &	totalReadData
	)

private

used for reading the data from the controller RAM/program memory The method will follow procedures outlined in the datasheet to intiate and read data from the controller, if using 4 pins it will take two transfers to deliver 8 bits instead of 1 if using 8 pins

Parameters

isDataReg	true if reading from the data memory(like RAM), false if reading from lcd controller register(where it has things like the busy status)
readDataBuf	buffer for storing the data, array of byte
totalReadData	how many bytes to read

void lcddriver::LcdDriver::parallelDataWrite	(	const uint8_t *	dataList,
		const uint32_t &	dataLen,
		const bool &	isDataReg
	)

private

used for sending data to the data pins(D0-D7) connected to the LCD The bits are shifted to each pin and then a proper setup and hold time is followed to make sure that the controller receives the data, the method will follow the correct procedure to intitiate connection with the controller

Parameters

dataList	array of data to be sent
dataLen	how many byte to send
isDataReg	is the destination data memory(like RAM) or lcd controller memory

void lcddriver::LcdDriver::parallelDataWriteSingle	(	const uint8_t &	data,
		const bool &	isDataReg
	)

private

used for writing a single byte to the lcd controller

Parameters

data	the byte to be written
isDataReg	is the destination data memory(like RAM) or lcd controller memory

void lcddriver::LcdDriver::parallelModeSwitch ( const bool & isInput )

private

switch all the data pins(like D0-D7) to input mode or output mode Used for quickly switching between receiving and sending data

Parameters

isInput if true then all data pin becomes input else become output

void lcddriver::LcdDriver::pinDescCheck ( uint32_t pinDesc[PIN_DESCRIPTION_LEN] )

private

check whether the array describing a pin is valid, will raise assert if not

Parameters

pinDesc array describing the pin

void lcddriver::LcdDriver::pinModeSwitch	(	const uint32_t	pinDesc[PIN_DESCRIPTION_LEN],
		const bool &	isInput
	)

private

switch a single pin to input/output

Parameters

pinDesc	array describing the pin
isInput	if true, set pin to input, otherwise, set pin to false

void lcddriver::LcdDriver::pinPadConfig ( const uint32_t pinDesc[PIN_DESCRIPTION_LEN] )

private

configure the pins on things like drive strength(affect rise/fall time of signal), push/pull mode

Parameters

pinDesc array describing the pin

bool lcddriver::LcdDriver::pinRead ( const uint32_t pinDesc[PIN_DESCRIPTION_LEN] )

private

Read whehther a pin is high or low.

Parameters

pinDesc array describing the pin

Returns: true pin is high; false pin is low

void lcddriver::LcdDriver::pinWrite	(	const uint32_t	pinDesc[PIN_DESCRIPTION_LEN],
		const bool &	output
	)

private

switch on/off a pin This is the lowest level function, used for toggling control pin for bitbanging during communcication

Parameters

pinDesc	array describing the pin
output	if true, set pin to high, otherwise, set to low

void lcddriver::LcdDriver::ramDataRead	(	uint8_t *	returnData,
		const uint32_t &	totalDataRead,
		const uint8_t &	startingRamAddr,
		const bool &	isDataRam
	)

private

Used for reading the RAM of the lcd controller, it can either be the data ram storing data to be displayed or the character generator ram, storing custom pattern The reading operation may result in the cursor moving.

Parameters

returnData	the buffer to store received data
totalDataRead	how many bytes to read from the RAM
startingRamAddr	starting address of the RAM, depending on the type of memory selected the method will append the correct bits to indicate the correct memory region, for example, for DDRAM, bit 7 is set
isDataRam	true if reading from data RAM(DDRAM), false if from character generator RAM(CGRAM)

void lcddriver::LcdDriver::ramDataWrite	(	const uint8_t *	data,
		const uint32_t	dataLen,
		const bool &	isTextMode
	)

private

Write to the RAM of the lcd controller, can be data ram or character generator RAM.

Parameters

data	arrays of data to be written
dataLen	len of the array of data
isTextMode	true if in text mode, text mode is helpful for writing to data RAM to be displayed, text mode will interpret special character like or $

void lcddriver::LcdDriver::registerSelect ( const bool & isDataReg )

private

select data(like RAM) or program register be switching the RS line

Parameters

isDataReg if true then the RS line is pulled high to indicate that transaction will target RAM region, otherwise target the lcd controller program memory

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

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation