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   PORTC
	Port used for control signals.
#define	LCD_CRTL_DDR   DDRC
	Data-Direction-Register for the control signals.
#define	LCD_RS   PC4
	Register-Select Pin of the Display.
#define	LCD_RW   PC2
	Read-Write-select Pin.
#define	LCD_EN   PC0
	Strobe Pin.
#define	LCD_DATA   PORTD
	Port used for 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 ()
	Clears the display by setting the whole memory to 0.
void	lcd_write_text (char *txt)
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, const uint8_t *bitmap, uint8_t w, uint8_t h)
	This function will plot a bitmap with the upper left corner to the given coordinates.
void	lcd_strobe ()
	Generates the strobe signal for writing data.
void	lcd_write_command (uint8_t cmd, uint8_t data)
	Writes a command and a data byte to the lcd.
uint8_t	lcd_read_byte ()
	Reads a byte from the display memory.

---

Define Documentation

#define LC7981_H_   LC7981_H_

protects this file from beeing double included

#define LCD_CRTL_DDR   DDRC

Data-Direction-Register for the control signals.

#define LCD_CTRL   PORTC

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_EN   PC0

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   PC4

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   PC2

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

(

)

[inline]

Clears the display by setting the whole memory to 0.

void lcd_gotoxy	(	uint8_t	x,
		uint8_t	y
	)			[inline]

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_off,
		uint8_t	y_off,
		const uint8_t *	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.
And if you know a better way to do this, tell me.

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.
Even though I can't remember her actual name.

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

uint8_t lcd_read_byte

(

)

[inline]

Reads a byte from the display memory.

lcd_gotoxy can be used to set the location. Important : lcd_gotoxy doesn't work in graphics mode yet.

Returns:

the byte which has been read

See also:

lcd_gotoxy

void lcd_strobe

(

)

[inline]

Generates the strobe signal for writing data.

This function is meant for internal usage only.

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

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

)