#include <avr/io.h>
#include <util/delay.h>
//macros
#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
//function prototype
void peekaboo(void);
void chechbusy(void);
void send_command(unsigned char command);
void send_data(unsigned char data);
//main function
int main(void)
{
  lcd_ctrl_dir |= 1 << RS | 1 << RW | 1 << EN;
  _delay_ms(20);
  send_command(0x01);
  _delay_ms(2);
  send_command(0x38);
  _delay_ms(50);
  send_command(0b00001110);
  _delay_ms(50);

  send_data(0x41);
  send_data(0x4E);
  send_data(0x49);
  send_data(0x53);
  send_data(0x48);
  while(1)
  {

  }
  return 0;
}

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

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

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

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