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

/* LCD with 4 bit mode for an ATMEGA32P processor

  _ LCD _       _ ATMEGA32P (arduino)_
  1   VSS   ->          GND
  2   VDD   ->          +5V
  3   V0    ->      Potentiometer
  4   RS    ->  PortB4 (Pin 12 arduino)
  5   RW    ->          GND
  6   E     ->  PortB3 (Pin 11 arduino)
  (7 - 10)  ->          ...
  11  D4    ->  PortD5 (Pin 5 arduino)
  12  D5    ->  PortD4 (Pin 4 arduino)
  13  D6    ->  PortD3 (Pin 3 arduino)
  14  D7    ->  PortD2 (Pin 2 arduino)
  15  A     ->    +5v with resistor
  16  K     ->          GND

*/

// LCD display size
#define LCD_START_LINE1   0x00
#define LCD_START_LINE2   0x40

// LCD ports/pins/ddr
#define LCD_RS_PORT PORTB
#define LCD_RS_PIN  4
#define LCD_RS_DDR  DDRB

#define LCD_E_PORT  PORTB
#define LCD_E_PIN   3
#define LCD_E_DDR   DDRB

#define LCD_D4_PORT PORTD
#define LCD_D4_PIN  5
#define LCD_D4_DDR  DDRD

#define LCD_D5_PORT PORTD
#define LCD_D5_PIN  4
#define LCD_D5_DDR  DDRD

#define LCD_D6_PORT PORTD
#define LCD_D6_PIN  3
#define LCD_D6_DDR  DDRD

#define LCD_D7_PORT PORTD
#define LCD_D7_PIN  2
#define LCD_D7_DDR  DDRD

//LCD instructions (see LCD-1602A datasheet)
#define LCD_CLEAR       0b00000001
#define LCD_HOME        0b00000010
#define LCD_ENTRY_MODE  0b00000110
#define LCD_DISPLAY_ON  0b00001100
#define LCD_DISPLAY_OFF 0b00001000
#define LCD_CURSOR_SET  0b10000000
#define LCD_FUNCTION_SET_8bit   0b00110000
#define LCD_FUNCTION_SET_4bit   0b00101000

// Functions
void dinit(void);
void lcd_init(void);
void lcd_write(uint8_t);
void lcd_cmd(uint8_t);
void lcd_char(uint8_t);
void lcd_string(uint8_t *);