#define F_CPU 16000000UL // Defining the CPU Frequency

#include <avr/io.h>      // Contains all the I/O Register Macros
#include <util/delay.h>  // Generates a Blocking Delay
#include <avr/interrupt.h> // Contains all interrupt vectors
#include <LiquidCrystal_I2C.h> 

LiquidCrystal_I2C lcd1(0x27, 16, 2); //  I2C lcd 


#define USART_BAUDRATE 9600 // Desired Baud Rate
#define BAUD_PRESCALER (((F_CPU / (USART_BAUDRATE * 16UL))) - 1)

#define ASYNCHRONOUS (0<<UMSEL00) // USART Mode Selection

#define DISABLED    (0<<UPM00)
#define EVEN_PARITY (2<<UPM00)
#define ODD_PARITY  (3<<UPM00)
#define PARITY_MODE  DISABLED // USART Parity Bit Selection

#define ONE_BIT (0<<USBS0)
#define TWO_BIT (1<<USBS0)
#define STOP_BIT ONE_BIT      // USART Stop Bit Selection

#define FIVE_BIT  (0<<UCSZ00)
#define SIX_BIT   (1<<UCSZ00)
#define SEVEN_BIT (2<<UCSZ00)
#define EIGHT_BIT (3<<UCSZ00)
#define DATA_BIT   EIGHT_BIT  // USART Data Bit Selection

#define RX_COMPLETE_INTERRUPT         (1<<RXCIE0)
#define DATA_REGISTER_EMPTY_INTERRUPT (1<<UDRIE0)

unsigned char GlobalTransmit;
unsigned char USART_ReceiveBuffer; // Global Buffer
unsigned char ReceiveBuffer[50];

static uint8_t p;
static uint8_t Received_Complete_Flag;



void USART_TransmitPolling(char * DataByte)
{
	uint8_t i;
  while(*DataByte!='\0')
	{

	while (( UCSR0A & (1<<UDRE0)) == 0) {}; // Do nothing until UDR is ready
	UDR0 = DataByte[i];
	
	  DataByte++;

	}
}

void UART_transmit_interrupt(char *data)
{

    while(*data!='\0')
    {
    GlobalTransmit=data[p];
		UCSR0B |= DATA_REGISTER_EMPTY_INTERRUPT; // Enables the Interrupt
    }
}

void print_on_lcd(char *bufferData)
{
   
   lcd1.setCursor(0, 1);
  while(*bufferData!='\0')
  {
    lcd1.print(*bufferData);
    bufferData++;
  }
}


void USART_Init()
{
	// Set Baud Rate
	UBRR0H = BAUD_PRESCALER >> 8;
	UBRR0L = BAUD_PRESCALER;
	
	// Set Frame Format
	UCSR0C = ASYNCHRONOUS | PARITY_MODE | STOP_BIT | DATA_BIT;
	
	// Enable Receiver and Transmitter
	UCSR0B = (1<<RXEN0) | (1<<TXEN0)| RX_COMPLETE_INTERRUPT;
	
	//Enable Global Interrupts
	sei();

  	USART_TransmitPolling("Treel");
    

}

void setup()
{
  lcd1.init();                       // initialize the I2C lcd
  lcd1.backlight(); 
  USART_Init();
	//UCSR0B |= RX_COMPLETE_INTERRUPT;
}

void loop()
{
   // USART_TransmitPolling(ReceiveBuffer);
 
   lcd1.setCursor(0, 0);
   lcd1.print("Data received:");
   print_on_lcd(ReceiveBuffer);
   //if( Received_Complete_Flag==0)
  // {
   UART_transmit_interrupt(ReceiveBuffer);
 //  }
}


ISR(USART_RX_vect)
{
	USART_ReceiveBuffer= UDR0;
  
  if(USART_ReceiveBuffer!=0)
  {
    if(USART_ReceiveBuffer!='\n')
    {
      ReceiveBuffer[p]=USART_ReceiveBuffer;
    }
     p++;

       
  }
  else
  {
      if(	USART_ReceiveBuffer='\0')
      {
     
      Received_Complete_Flag=1;
      ReceiveBuffer[p]=USART_ReceiveBuffer;
      p=0;
     //  memset(ReceiveBuffer,0,50*sizeof(ReceiveBuffer[0]));
      }
     // memset(ReceiveBuffer,0,50*sizeof(ReceiveBuffer[0]));
  }
 USART_ReceiveBuffer=0;
 // UDR0=USART_ReceiveBuffer[0];
// UART_transmit_interrupt( ReceiveBuffer[p]);

}

ISR(USART_UDRE_vect)
{
	
		UDR0 =GlobalTransmit;
    p++;
    if(GlobalTransmit=='\0')
    {
      p=0;
      memset(ReceiveBuffer,0,50*sizeof(ReceiveBuffer[0]));
      Received_Complete_Flag=0;

    }
	  UCSR0B &= ~DATA_REGISTER_EMPTY_INTERRUPT; // Disables the Interrupt, uncomment for one time transmission of data
    GlobalTransmit=0;
    //print_on_lcd(ReceiveBuffer);
}