include/lc7981.h File Reference

#include <avr/io.h>
#include <util/delay.h>
#include <avr/pgmspace.h>

Go to the source code of this file.

Defines
#define	LC7981_H_   LC7981_H_
	protects this file from beeing double included
#define	LCD_CTRL   PORTA
	Port used for control signals.
#define	LCD_CRTL_DDR   DDRA
	Data-Direction-Register for the control signals.
#define	LCD_RS   PA4
	Register-Select Pin of the Display.
#define	LCD_RW   PA2
	Read-Write-select Pin.
#define	LCD_EN   PA0
	Strobe Pin.
#define	LCD_DATA   PORTD
	Port used for data.
#define	LCD_DATA_PIN   PIND
	Port used for reading the data.
#define	LCD_DATA_DDR   DDRD
	Data-Direction-Register for data.
#define	lcd_rs_high()   (LCD_CTRL |= (1 << LCD_RS))
	Set the Register-Select pin high.
#define	lcd_rs_low()   (LCD_CTRL &= ~(1 << LCD_RS))
	Set the Register-Select pin low.
#define	lcd_rw_high()   (LCD_CTRL |= (1 << LCD_RW))
	Set the Read-Write-Select pin high.
#define	lcd_rw_low()   (LCD_CTRL &= ~(1 << LCD_RW))
	Set the Register-Select pin low.
#define	lcd_en_high()   (LCD_CTRL |= (1 << LCD_EN))
	Set the strobe pin high.
#define	lcd_en_low()   (LCD_CTRL &= ~(1 << LCD_EN))
	Set the strobe pin low.
#define	LCD_TEXT   0
	Constant for text mode.
#define	LCD_TEXT_LINES   10
	Number of lines in text mode.
#define	LCD_TEXT_COLUMNS   26
	Number of columns in text mode.
#define	LCD_GRAPHIC   1
	Constant for graphic mode.
#define	LCD_GRAPHIC_WIDTH   160
	Horizontal display size in pixels.
#define	LCD_GRAPHIC_HEIGHT   80
	Vertical display size in pixels.
#define	PIXEL_ON   1
	see lcd_plot_pixel
#define	PIXEL_OFF   0
	see lcd_plot_pixel
Functions
void	lcd_init (uint8_t mode)
	lcd_init set the to default values.
void	lcd_clear (void)
	Clears the display by setting the whole memory to 0.
void	lcd_write_text (char *txt)
	Outputs text in at the current cursor position.
void	lcd_gotoxy (uint8_t x, uint8_t y)
	Set the display cursor to a specific location.
void	lcd_plot_pixel (uint8_t x, uint8_t y, uint8_t set)
	set or unset a pixel at the specified location
void	lcd_plot_bitmap (uint8_t x, uint8_t y, PGM_P bitmap, uint8_t w, uint8_t h)
	This function will plot a bitmap with the upper left corner to the given coordinates.
void	lcd_plot_char (uint8_t x, uint8_t y_off, uint8_t c, uint8_t fw, uint8_t fh, PGM_P font)
	Plots a single character in graphicmode.
void	lcd_plot_text (uint8_t x, uint8_t y_off, const char *text, uint8_t fw, uint8_t fh, PGM_P font)
	Plots a text using lcd_plot_char.
void	lcd_plot_pgmtext (uint8_t x, uint8_t y_off, PGM_P text, uint8_t fw, uint8_t fh, PGM_P font)
	Plots a text using lcd_plot_char.
static void	lcd_strobe (void)
	Generates the strobe signal for writing data.
static void	lcd_write_command (uint8_t cmd, uint8_t data)
	Writes a command and a data byte to the lcd.
static uint8_t	lcd_read_byte (uint16_t pos)
	Reads a byte from the display memory.
static void	lcd_write_byte (uint16_t pos, uint8_t byte)

---

Define Documentation

#define LC7981_H_   LC7981_H_

protects this file from beeing double included

#define LCD_CRTL_DDR   DDRA

Data-Direction-Register for the control signals.

#define LCD_CTRL   PORTA

Port used for control signals.

#define LCD_DATA   PORTD

Port used for data.

#define LCD_DATA_DDR   DDRD

Data-Direction-Register for data.

#define LCD_DATA_PIN   PIND

Port used for reading the data.

#define LCD_EN   PA0

Strobe Pin.

 

#define lcd_en_high

(

)

(LCD_CTRL |= (1 << LCD_EN))

Set the strobe pin high.

 

#define lcd_en_low

(

)

(LCD_CTRL &= ~(1 << LCD_EN))

Set the strobe pin low.

#define LCD_GRAPHIC   1

Constant for graphic mode.

#define LCD_GRAPHIC_HEIGHT   80

Vertical display size in pixels.

#define LCD_GRAPHIC_WIDTH   160

Horizontal display size in pixels.

#define LCD_RS   PA4

Register-Select Pin of the Display.

 

#define lcd_rs_high

(

)

(LCD_CTRL |= (1 << LCD_RS))

Set the Register-Select pin high.

 

#define lcd_rs_low

(

)

(LCD_CTRL &= ~(1 << LCD_RS))

Set the Register-Select pin low.

#define LCD_RW   PA2

Read-Write-select Pin.

 

#define lcd_rw_high

(

)

(LCD_CTRL |= (1 << LCD_RW))

Set the Read-Write-Select pin high.

 

#define lcd_rw_low

(

)

(LCD_CTRL &= ~(1 << LCD_RW))

Set the Register-Select pin low.

#define LCD_TEXT   0

Constant for text mode.

#define LCD_TEXT_COLUMNS   26

Number of columns in text mode.

#define LCD_TEXT_LINES   10

Number of lines in text mode.

#define PIXEL_OFF   0

see lcd_plot_pixel

#define PIXEL_ON   1

see lcd_plot_pixel

---

Function Documentation

void lcd_clear

(

void

)

Clears the display by setting the whole memory to 0.

void lcd_gotoxy	(	uint8_t	x,
		uint8_t	y
	)

Set the display cursor to a specific location.

Right now this does only work in text mode, since there's no need for it now in graphics mode.
If the x and y values are to big, the function does nothing.

Parameters:

	x	the horizontal cursorposition (starts at 0)
	y	the vertical cursorposition (starts at 0)

void lcd_init

(

uint8_t

mode

)

lcd_init set the to default values.

Parameters:

mode

LCD_TEXT for text mode and LCD_GRAPHIC for graphic mode

void lcd_plot_bitmap	(	uint8_t	x,
		uint8_t	y,
		PGM_P	bitmap,
		uint8_t	w,
		uint8_t	h
	)

This function will plot a bitmap with the upper left corner to the given coordinates.

If the bitmap doesn't fit on the display at this location, nothing is drawn at all.
Unset pixels are treated as transparent
This function is by far the most tricky piece of code in this project,
don't worry if you don't understand it at first sight.
Actually it just loops bitwise through the bitmap and uses some
nice bit shifting magic to get it anywhere you want.

Parameters:

	x	horizontal position of the bitmap
	y	vertical position of the bitmap
	bitmap	pointer to the bitmap in pgmspace
	w	width of the bitmap
	h	height of the bitmap

This function is dedicated to Greta, one of the most important persons in my life so far.

void lcd_plot_char	(	uint8_t	x_off,
		uint8_t	y_off,
		uint8_t	c,
		uint8_t	fw,
		uint8_t	fh,
		PGM_P	font
	)

Plots a single character in graphicmode.

Each character of the font is stored linewise.
This means for a 8x8 Pixel font the 8 bytes are needed.
The first byte is the first line and the last byte is the last line.
The next 8byte are the next character.

If the position is too close to the display edge so it can't be displayed completely,
It won't be displayed at all.

Parameters:

	x_off	horizontal position of the character
	y_off	vertical position of the character
	c	the character or it's ascii code
	fw	width of the font (we start counting from 0, so a 10px width font will have fw = 9)
	fh	height of the font (we start counting from 0, so a 10px height font will have fh = 9)
	font	pointer to the flash area where the font is stored

void lcd_plot_pgmtext	(	uint8_t	x_off,
		uint8_t	y_off,
		PGM_P	text,
		uint8_t	fw,
		uint8_t	fh,
		PGM_P	font
	)

Plots a text using lcd_plot_char.

Parameters:

	x_off	horizontal position of the character
	y_off	vertical position of the character
	text	flash area where the text is stored
	fw	width of the font (we start counting from 0, so a 10px width font will have fw = 9)
	fh	height of the font (we start counting from 0, so a 10px height font will have fh = 9)
	font	pointer to the flash area where the font is stored

See also:

lcd_plot_char

lcd_plot_text

void lcd_plot_pixel	(	uint8_t	x,
		uint8_t	y,
		uint8_t	set
	)

set or unset a pixel at the specified location

Parameters:

	x	horizontal position of the pixel (starts at 0)
	y	horizontal position of the pixel (starts at 0)
	set	can be PIXEL_ON or PIXEL_OFF

void lcd_plot_text	(	uint8_t	x_off,
		uint8_t	y_off,
		const char *	text,
		uint8_t	fw,
		uint8_t	fh,
		PGM_P	font
	)

Plots a text using lcd_plot_char.

Parameters:

	x_off	horizontal position of the character
	y_off	vertical position of the character
	text	the text that is plotted
	fw	width of the font (we start counting from 0, so a 10px width font will have fw = 9)
	fh	height of the font (we start counting from 0, so a 10px height font will have fh = 9)
	font	pointer to the flash area where the font is stored

See also:

lcd_plot_char

static uint8_t lcd_read_byte

(

uint16_t

pos

)

[inline, static]

Reads a byte from the display memory.

Parameters:

pos

16bit address for display memory

Returns:

the byte which has been read

See also:

lcd_gotoxy

static void lcd_strobe

(

void

)

[inline, static]

Generates the strobe signal for writing data.

This function is meant for internal usage only.

static void lcd_write_byte	(	uint16_t	pos,
		uint8_t	byte
	)			[inline, static]

static void lcd_write_command	(	uint8_t	cmd,
		uint8_t	data
	)			[inline, static]

Writes a command and a data byte to the lcd.

Parameters:

	cmd	the command byte
	data	the data that is going to be written after the command

void lcd_write_text

(

char *

txt

)

Outputs text in at the current cursor position.

If a \n occurs in the last line of the display, all the other line will be 'scrolled' up. This function is textmode only. The the second line becomes the first, the third the second and so on ...

Parameters:

txt

the text