//--------------------------------------------------------
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
//--------------------------------------------------------
#ifndef F_CPU
#define F_CPU 16000000UL
#endif
#define BAUD 9600
#define MYUBRR(F_CPU,BAUD)((F_CPU/16/BAUD)-1)
//--------------------------------------------------------
#define E  (1<<PD3)
#define RS (1<<PD2)
//--------------------------------------------------------
ISR(USART_RX_vect)
{
  while(!(UCSR0A & (1<<RXC0))){};
  unsigned char received = USART_Receive();
  unsigned char _destination[32] = "";
  strcpy1(_destination ,received);
  lcd_setcursor(1,2);  
  lcd_print("                ");
  _delay_ms(200);  
  lcd_setcursor(1,2);    
  lcd_print(_destination);
  //lcd_char(_destination);
  _delay_ms(200);
}
//--------------------------------------------------------
void USART_Init(uint32_t ubrr)
{
  /*Set BaudRate*/
  UBRR0L = MYUBRR(F_CPU,ubrr);
  UBRR0H = (MYUBRR(F_CPU,ubrr) >> 8);
  /*Enable Receiver and Transmitter*/
  UCSR0B = (1<<RXEN0) | (1<<TXEN0);
  /*Set Frame format: 8data, 2stop bit*/
  UCSR0C = (1<<USBS0) | (3<<UCSZ00);
}
uint32_t USART_Receive(void)
{
  while(!(UCSR0A & (1<<RXC0)));
  return UDR0;
}
void USART_Transmit(unsigned char _data)
{
  //Wait for empty transmit buffer
  while(!(UCSR0A & (1<<UDRE0)));
  //Put data into buffer, sends the data
  UDR0 = _data;
}
//--------------------------------------------------------
//latch E pin command
void latch(void)
{
  PORTD |= E;     //send high
  _delay_us(500);  //wait
  PORTD &= ~E;    //send low
  _delay_us(500); //wait
}
//to send commands in the right order
void lcd_cmd(uint8_t cmd)
{
  PORTD = (PORTD & 0x0F) | (cmd & 0xF0); //send high nibble
  PORTD &= ~RS;                          //send 0 to select command register
  latch();                               //latch the data
  PORTD = (PORTD & 0x0F) | (cmd << 4);   //send low nibble
  latch();                               //latch the data
}
//init sequence
void lcd_init()
{
  //Init ports for LCD
  DDRD |= (1<<PD2) | (1<<PD3) | (1<<PD4) | (1<<PD5) | (1<<PD6) | (1<<PD7);
  //send pulse to latch the data
  latch();
  _delay_ms(2); //delay for stable power
  //command to set up the LCD
  lcd_cmd(0x33);
  _delay_us(100);
  lcd_cmd(0x32);
  _delay_us(100);
  lcd_cmd(0x28); //2 lines 5x7 matrix dot
  _delay_us(100);
  //lcd_cmd(0x0E); // display ON, cursor ON
  lcd_cmd(0x0C);   //display ON, cursor ON
  _delay_us(100);
  lcd_cmd(0x01);   //clear LCD
  _delay_ms(20);   //wait
  lcd_cmd(0x06);   //shift cursor to right
  _delay_ms(1);
}

void lcd_setcursor(uint8_t x, uint8_t y)
{
  uint8_t firstcharadr[] = {0x80,0xC0,0x94,0xD4};
  lcd_cmd(firstcharadr[y-1]+ x-1);
  _delay_us(1000);
}
void lcd_char(uint8_t data)
{
  PORTD = (PORTD & 0x0F) | (data & 0xF0); //send high nibble
  PORTD |= RS;                            //send one to select command register
  latch();
  PORTD = (PORTD & 0x0F) | (data<<4);     //send high nibble
  latch();
  
}

void lcd_print(char *str)
{
  uint8_t k = 0;
  while(str[k] != 0)
  {
    lcd_char(str[k]);
    k++;
  }
}

char *strcpy1(char dst[], char src[]) {
    int i = 0;
    while(src[i] != '\0')
    {
        dst[i]=src[i];
        i++;
    }
    dst[i]='\0';
    return dst;
}

int main()
{
  USART_Init(BAUD);
  lcd_init();
  lcd_setcursor(1,1);
  USART_Transmit('R');
  lcd_print("USART Test :");
  
  UCSR0B |= (1<<RXCIE0);
  sei();
  while(1)
  {
    lcd_setcursor(1,2);
    for(int i=0;i<16;i++){
      lcd_print("-");
      _delay_ms(200);
    }
    lcd_setcursor(1,2);
    lcd_print("                ");
    _delay_ms(200);
    
  }
  return 0;
}