HD44780 LCD driver

Driver for the Hitachi HD44780 LCD driver. More...

Detailed Description

Driver for the Hitachi HD44780 LCD driver.

Note

The driver currently supports direct addressing, no I2C

Files
file	hd44780_internal.h
	Internal config and parameters for the HD44780 display.
file	hd44780_params.h
	Pinout config for the HD44780 display.
file	hd44780.h
	Interface definition for the HD44780 LCD driver.

Data Structures
struct	hd44780_params_t
	Parameters needed for device initialization. More...
struct	hd44780_t
	Device descriptor for HD44780 LCD. More...

Macros
#define	HD44780_MAX_COLS   (40U)
	Maximal number of columns supported by the driver.
#define	HD44780_MAX_ROWS   (4U)
	Maximal number of rows supported by the driver.
#define	HD44780_MAX_PINS   (8U)
	Number of data pins for communication 4 or 8.
#define	HD44780_CGRAM_SIZE   (8U)
	Size of RAM for custom chars. More...

Enumerations
enum	hd44780_state_t { HD44780_OFF, HD44780_ON }
	Simple state values. More...

Functions
int	hd44780_init (hd44780_t *dev, const hd44780_params_t *params)
	Initialize the given driver. More...
void	hd44780_clear (const hd44780_t *dev)
	Clear display, delete all chars. More...
void	hd44780_home (const hd44780_t *dev)
	Reset cursor to row 0 and column 0. More...
void	hd44780_set_cursor (const hd44780_t *dev, uint8_t col, uint8_t row)
	Set cursor to specific position in column and row. More...
void	hd44780_display (hd44780_t *dev, hd44780_state_t state)
	Turn display on or off. More...
void	hd44780_cursor (hd44780_t *dev, hd44780_state_t state)
	Show cursor, on or off. More...
void	hd44780_blink (hd44780_t *dev, hd44780_state_t state)
	Blink cursor, on or off. More...
void	hd44780_scroll_left (const hd44780_t *dev)
	Enable left scrolling. More...
void	hd44780_scroll_right (const hd44780_t *dev)
	Enable right scrolling. More...
void	hd44780_left2right (hd44780_t *dev)
	Set display direction left to right. More...
void	hd44780_right2left (hd44780_t *dev)
	Set display direction right to left. More...
void	hd44780_autoscroll (hd44780_t *dev, hd44780_state_t state)
	Display autoscroll on or off. More...
void	hd44780_create_char (const hd44780_t *dev, uint8_t location, uint8_t charmap[])
	Create and store a custom character on display memory. More...
void	hd44780_write (const hd44780_t *dev, uint8_t value)
	Write a single character on the LCD. More...
void	hd44780_print (const hd44780_t *dev, const char *data)
	Write a string on the LCD. More...

Macro Definition Documentation

HD44780_CGRAM_SIZE

#define HD44780_CGRAM_SIZE   (8U)

Size of RAM for custom chars.

Generally the driver could support 8 chars of size 5x8 or 4 of size 5x10. However, most displays only use the former, which is (hard wired) default.

Definition at line 55 of file hd44780.h.

Enumeration Type Documentation

hd44780_state_t

enum hd44780_state_t

Simple state values.

Enumerator
HD44780_OFF	disable feature
HD44780_ON	enable feature

Definition at line 83 of file hd44780.h.

Function Documentation

hd44780_autoscroll()

void hd44780_autoscroll	(	hd44780_t *	dev,
		hd44780_state_t	state
	)

Display autoscroll on or off.

Parameters

[in]	dev	device descriptor of LCD
[in]	state	scroll on or off

hd44780_blink()

void hd44780_blink	(	hd44780_t *	dev,
		hd44780_state_t	state
	)

Blink cursor, on or off.

Parameters

[in]	dev	device descriptor of LCD
[in]	state	blink on or off

hd44780_clear()

void hd44780_clear

(

const hd44780_t *

dev

)

Clear display, delete all chars.

Parameters

[in]

dev

device descriptor of LCD

hd44780_create_char()

void hd44780_create_char	(	const hd44780_t *	dev,
		uint8_t	location,
		uint8_t	charmap[]
	)

Create and store a custom character on display memory.

Parameters

[in]	dev	device descriptor of LCD
[in]	location	memory location
[in]	charmap	character bitmap

Precondition

charmap has to be of size HD44780_CGRAM_SIZE, which is 8 by default

hd44780_cursor()

void hd44780_cursor	(	hd44780_t *	dev,
		hd44780_state_t	state
	)

Show cursor, on or off.

Parameters

[in]	dev	device descriptor of LCD
[in]	state	cursor on or off

hd44780_display()

void hd44780_display	(	hd44780_t *	dev,
		hd44780_state_t	state
	)

Turn display on or off.

Parameters

[in]	dev	device descriptor of LCD
[in]	state	display on or off

hd44780_home()

void hd44780_home

(

const hd44780_t *

dev

)

Reset cursor to row 0 and column 0.

Parameters

[in]

dev

device descriptor of LCD

hd44780_init()

int hd44780_init	(	hd44780_t *	dev,
		const hd44780_params_t *	params
	)

Initialize the given driver.

Parameters

[out]	dev	device descriptor of display to initialize
[in]	params	configuration parameters

Returns

0 on success, otherwise error

hd44780_left2right()

void hd44780_left2right

(

hd44780_t *

dev

)

Set display direction left to right.

Parameters

[in]

dev

device descriptor of LCD

hd44780_print()

void hd44780_print	(	const hd44780_t *	dev,
		const char *	data
	)

Write a string on the LCD.

Parameters

[in]	dev	device descriptor of LCD
[in]	data	the string to print

hd44780_right2left()

void hd44780_right2left

(

hd44780_t *

dev

)

Set display direction right to left.

Parameters

[in]

dev

device descriptor of LCD

hd44780_scroll_left()

void hd44780_scroll_left

(

const hd44780_t *

dev

)

Enable left scrolling.

Parameters

[in]

dev

device descriptor of LCD

hd44780_scroll_right()

void hd44780_scroll_right

(

const hd44780_t *

dev

)

Enable right scrolling.

Parameters

[in]

dev

device descriptor of LCD

hd44780_set_cursor()

void hd44780_set_cursor	(	const hd44780_t *	dev,
		uint8_t	col,
		uint8_t	row
	)

Set cursor to specific position in column and row.

Parameters

[in]	dev	device descriptor of LCD
[in]	col	column position
[in]	row	row position

hd44780_write()

void hd44780_write	(	const hd44780_t *	dev,
		uint8_t	value
	)

Write a single character on the LCD.

Parameters

[in]	dev	device descriptor of LCD
[in]	value	the character to print, i.e., memory location