#ifndef __LCD_H_
#define __LCD_H_

#include <stdint.h>
#include <avr/pgmspace.h>

// This driver provides access to an LCD display with HD44780 controller.
// Only the 4bit communication mode is implemented.

//Example for the Required settings in hardware.h:
// The HD44780 Display is connected to Port D
// PD2 = RS
// GND = R/W
// PD3 = E
// PD4..PD7 = DB4..DB7
#define LCD_PORT_INIT  { DDRD |= 0b11111100; }
#define LCD_RS_HIGH    { PORTD |=  (1<<PD2); }
#define LCD_RS_LOW     { PORTD &= ~(1<<PD2); }
#define LCD_E_HIGH     { PORTD |=  (1<<PD3); }
#define LCD_E_LOW      { PORTD &= ~(1<<PD3); }
#define LCD_DATA_LOW_NIBBLE(b)  { PORTD = (PORTD & 0x0F) | (b << 4); }
#define LCD_DATA_HIGH_NIBBLE(b) { PORTD = (PORTD & 0x0F) | (b & 0xF0); }

// The DDRAM stores the display data (the characters).
// The first line begins at address 0x00, the second line begins at address 0x40.

// The CGRAM can be used to define custom characters.
// In 5x8 pixels mode, each custom character occupies 8 bytes (8 rows from top
// to bottom, each uses only the lower 5 bits). Maximum 8 custom characters.
// In 5x10 pixels mode, each custom character occupies 10 bytes (10 rows from top
// to bottom, each uses only the lower 5 bits). Maximum 6 custom characters.
// The custom characters appear when you write character codes 0..7 to the DDRAM.

// Example to generate and display a rectangle in the second row:
//    LCD_init(LCD_2_LINES+LCD_5x8_FONT);    
//    LCD_command(LCD_SET_CGRAM_ADDRESS+0x00);
//    LCD_data(0b11111);
//    LCD_data(0b10001);
//    LCD_data(0b10001);
//    LCD_data(0b10001);
//    LCD_data(0b10001);
//    LCD_data(0b10001);
//    LCD_data(0b10001);
//    LCD_data(0b11111);
//    LCD_command(LCD_SET_DDRAM_ADDRESS+0x40);
//    LCD_data(0); 


// Initialize the display controller.
void LCD_init(uint8_t options);

// Send a command.
void LCD_command(uint8_t cmd);

// Commands and options (add options to the command):

#define LCD_FUNCTION_SET        0b00100000
#define    LCD_1_LINE           0b0000
#define    LCD_2_LINES          0b1000
#define    LCD_5x8_FONT         0b0000
#define    LCD_5x10_FONT        0b0100

// Clear display and set cursor to home position.
#define LCD_CLEAR_DISPLAY       0b00000001

// Set cursor to the home position and reset the shift position.
// The DDRAM content remains unchanged.
// Note that this command takes much more time than the clear display command.
#define LCD_RETURN_HOME         0b00000010

// Set entry mode = what happens after writing a character to the DDRAM.
#define LCD_ENTRY_MODE_SET      0b00000100
#define    LCD_DECREMENT        0b00
#define    LCD_INCREMENT        0b10
#define    LCD_SHIFT            0b01

// Control which features are on:
#define LCD_ON_OFF_CONTROL      0b00001000
#define    LCD_OFF              0b000
#define    LCD_DISPLAY          0b100
#define    LCD_CURSOR           0b010
#define    LCD_BLINKING         0b001

// Shift the cursor
#define LCD_SHIFT_CURSOR_LEFT   0b00010000
#define LCD_SHIFT_CURSOR_RIGHT  0b00010100

// Shift the display
#define LCD_SHIFT_DISPLAY_LEFT  0b00011000
#define LCD_SHIFT_DISPLAY_RIGHT 0b00011100

// Set address of character generator RAM, the following data are written to the CGRAM.
// Add the 6bit address value to the command.
#define LCD_SET_CGRAM_ADDRESS   0b01000000

// Set the address of display data RAM, the following data are written to the DDRAM.
// Add the 7bit address value to the command.
// Note that the second line ususally begins at address 0x40.
#define LCD_SET_DDRAM_ADDRESS   0b10000000

// Write one byte to the data register (CGRAM or DDRAM).
void LCD_data(uint8_t data);

// Write a string to the data register (CGRAM or DDRAM).
void LCD_write(char* text);

// Write a string from program memory to the data register (CGRAM or DDRAM).
void LCD_write_P(PGM_P text);

#endif //__LCD_H_