unsigned char varTransmis;
unsigned char varPrimit;
void setup() {

 UBRR0 = 104;
 UCSR0A = 0;
 UCSR0B |= (1<<TXEN0) | (1<<RXEN0);
 UCSR0C |= (1<<UCSZ01) | (1<<UCSZ00);
}

void USART_send_one_character(unsigned char data)
{
  while(!(UCSR0A&(1<<UDRE0)));
  UDR0=data;
}
unsigned char USART_receive()
{
  while(!(UCSR0A & (1<<RXC0)));
  return UDR0;
}
void loop()
{
 varPrimit = USART_receive();
 USART_send_one_character(varPrimit);
 delay(500);
}