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

#define F_CPU 16000000UL
#define lcd_addr 0x27
#define lcd_en 0x04
#define lcd_rs 0x01
#define lcd_rw 0x02

int column[2] = {0,64};

void twi_init(void)
{
  TWSR |= (1 << TWPS1) | (1 << TWPS0);
  TWCR |= (1 << TWEN);
  TWBR = 0x48;
}

void twi_start(void)
{
  TWCR |= (1 << TWEN) | (1 << TWSTA) | (1 << TWINT);
  while(!(TWCR & (1 << TWINT)));
}

void twi_stop(void)
{
  TWCR |= (1 << TWEN) | (1 << TWSTO) | (1 << TWINT);
}

void twi_write(uint8_t data)
{
  TWDR = data;
  TWCR |= (1 << TWEN) | (1 << TWINT);
  while(!(TWCR & (1 << TWINT)));
}

void lcd_init(void)
{
  _delay_ms(20);
  lcd_command(0x33);
  lcd_command(0x32);
  lcd_command(0x28);
  lcd_command(0x0F);
  lcd_command(0x06);
  lcd_command(0x01);
  _delay_ms(2);
}

void lcd_command(uint8_t command)
{
  uint8_t upper = (command & 0xF0) | lcd_en;
  uint8_t lower = ((command << 4) & 0xF0) | lcd_en;
  twi_start();
  twi_write((lcd_addr << 1) | 0);
  twi_write(upper);
  _delay_ms(1);
  twi_write(upper & ~(lcd_en));
  _delay_ms(200);
  twi_write(lower);
  _delay_ms(1);
  twi_write(lower & ~(lcd_en));
  twi_stop();
}

void lcd_data(uint8_t data)
{
  uint8_t upper = (data & 0xF0) | lcd_en | lcd_rs;
  uint8_t lower = ((data << 4) & 0xF0) | lcd_en | lcd_rs;
  twi_start();
  twi_write((lcd_addr << 1) | 0);
  twi_write(upper);
  _delay_ms(1);
  twi_write(upper & ~(lcd_en));
  _delay_ms(200);
  twi_write(lower);
  _delay_ms(1);
  twi_write(lower & ~(lcd_en));
  twi_stop();
}

void send_string(char *string)
{
  while(*string)
  {
    lcd_data(*string++);
  }
}

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

int main(void)
{
  lcd_init();
  twi_init();
  set_cursor(0,0);
  lcd_data(0x44);
  send_string("anish");
  while(1)
  {

  }
  return 0;
}