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

#define lcd_data PORTD
#define lcd_data_dir DDRD
#define lcd_ctrl PORTB
#define lcd_ctrl_dir DDRB
#define RS PB1
#define RW PB2
#define EN PB3

char column_y[2] = {0,64};

void lcd_init(void);
void send_command(unsigned char command);
void send_data(unsigned char data);
void set_cursor(uint8_t x,uint8_t y);
void send_integer_cursor(uint8_t x,uint8_t y,char lenght,int integer);
void send_string_cursor(uint8_t x,uint8_t y,char *string);
void check_busy(void);
void peekaboo(void);
void send_string(char *string);

int main(void)
{
  char temp[3];
  lcd_init();

  // send_string_cursor(0,0,"anish");
  // send_integer_cursor(6,0,3,69);
  // send_string_cursor(9,0,"anantha");
  while(1)
  {
    for(int y=0;y<2;y++)
    {
      for(int x=0;x<16;x++)
      {
        itoa(x,temp,10);
        set_cursor(7,0);
        send_string("X = ");
        send_string(temp);
        itoa(y,temp,10);
        set_cursor(7,1);
        send_string("Y = ");
        send_string(temp);
        set_cursor(x,y);
        send_string("x");
        _delay_ms(400);
        set_cursor(x,y);
        send_string(" ");
        itoa(x,temp,10);
        set_cursor(7,0);
        send_string("      ");
        itoa(y,temp,10);
        set_cursor(7,1);
        send_string("      ");
      }
    }
  }
  return 0;
}

void lcd_init(void)
{
  lcd_ctrl_dir |= (1 << RS) | (1 << EN) | (1 << RW);
  _delay_ms(15);
  send_command(0x01);
  _delay_ms(2);
  send_command(0x38);
  _delay_ms(50);
  send_command(0x0E);
  _delay_ms(50);
}

void check_busy(void)
{
  lcd_data_dir = 0;
  lcd_ctrl |= (1 << RW);
  lcd_ctrl &= ~(1 << RS);
  while(lcd_data >= 0x80)
  {
    peekaboo();
  }
  lcd_data_dir = 0xFF;
}

void peekaboo(void)
{
  lcd_ctrl |= (1 << EN);
  asm volatile("nop");
  asm volatile("nop");
  lcd_ctrl &= ~(1 << EN);
}

void send_command(unsigned char command)
{
  check_busy();
  lcd_data = command;
  lcd_ctrl &= ~((1 << RS) | (1 << RW));
  peekaboo();
  lcd_data = 0;
}

void send_data(unsigned char data)
{
  check_busy();
  lcd_data = data;
  lcd_ctrl &= ~(1 << RW);
  lcd_ctrl |= (1 << RS);
  peekaboo();
  lcd_data = 0;
}

void set_cursor(uint8_t x,uint8_t y)
{
  send_command(0x80 + x + column_y[y]);
}

void send_string(char *string)
{
  while(*string != 0)
  {
    send_data(*string++);
  }
}

void send_integer_cursor(uint8_t x,uint8_t y,char lenght,int integervalue)
{
  char buffer[lenght];
  itoa(integervalue,buffer,10);
  for(int i=0;i<lenght;i++)
  {
    send_string(" ");
  }
  send_string_cursor(x,y,buffer);
}

void send_string_cursor(uint8_t x,uint8_t y,char *string)
{
  set_cursor(x,y);
  send_string(string);
}