#include <stdlib.h>
#include <avr/io.h>

void sleep()
{
	for (int i = 0;i < 6300;i++)
		asm volatile("nop");
}

void LCD_command(unsigned char data)
{
	unsigned char dataBits ;
        dataBits = PORTD & 0xF0;
        PORTD = dataBits |((data>>4)&0x0F);
        lcd_renew();
        PORTD = dataBits | (data&0x0F);
        lcd_renew();
	PORTD = dataBits | 0x0F;
	sleep();
}

void LCD_enable()
{
	PORTD |= _BV(5);
	asm volatile("nop");
	asm volatile("nop");
	asm volatile("nop");
	asm volatile("nop");
	PORTD &= ~_BV(5);
}

void LCD_Text()
{
	PORTD |= _BV(4);
	unsigned char data = 'a';
	unsigned char dataBits ;
        dataBits = PORTD & 0xF0;
        PORTD = dataBits |((data>>4)&0x0F);
        lcd_renew();

        PORTD = dataBits | (data&0x0F);
        lcd_renew();

	PORTD = dataBits | 0x0F;
	PORTD &= ~_BV(4);
	sleep();
}

void LCD_init()
{
	for (int i= 0;i < 50;i++)
		sleep();

	int init = 0b00000111;
	PORTD = init;
	LCD_enable();
	sleep();
	LCD_enable();
	sleep();
	LCD_enable();
	sleep();

	init = 0b00000010;
	PORTD = init;
	LCD_enable();
	sleep();
	PORTD = 0x00;

	init = 0b00101000;
	LCD_command();

	init = 0b00001110;
	LCD_command();

	init = 0b00000101;
	LCD_command();

	init = 0b00000100;
	LCD_command();
}

void main(void)
{
	DDRD = 0xFF;	//Definieren Port D als output
	LCD_init();
	LCD_Text();	//gebe test-zeichen aus
}