#define E PB0
#define RS PB1

void lcd_init(void);
void lcd_data(char*);
void lcd_char(uint8_t);


int main()
{
  lcd_init();
  lcd_data("Hallo AVR!");
  while(1);
  return 0;
}


void lcd_init(void)
{
  DDRD = 0xFF; //8-bit Datenport auf Ausgang
  DDRB |= (1<<E) | (1<<RS); //E und RS auf Ausgang
  PORTB &= ~((1<<E) | (1<<RS)); //E=0, RS=0
  
  lcd_command(0x01); //Anzeige leeren
  lcd_command(0x38); //8-bit Modus, 2 zeilig, 5x8 Matrix (Function set)
  lcd_command(0x0E); //Anzeige an und Cursor an (Display control)
  lcd_command(0x06); //Adresse inkrementieren und Cursor nach rechts verschieben (Entry Mode set)
}

void lcd_command(uint8_t cmd) 
{
  PORTB &= ~(1<<RS); //RS=0
  PORTD = cmd;
  PORTB |= (1<<E); //E=1
  _delay_us(1);
  PORTB &= ~(1<<E); //E=0
}

void lcd_data(char *str)
{
  while((*str) != '\0')
  {
    lcd_char(*str);
    ++str;
  }
}

void lcd_char(uint8_t ch)
{
  _delay_ms(500);
  PORTB |= (1<<RS); //RS=1
  PORTD = ch;
  PORTB |= (1<<E); //E=1
  _delay_us(1);
  PORTB &= ~(1<<E); //E=0
}