void USART_init(void)
{
  cli();
  UCSRB = (1<<RXEN)|(1<<RXCIE);
  UCSRC = 0b10000110;
  UBRRH = 0x00;
  UBRRL = (unsigned char)47;
  sei();
}

void USART_Init( unsigned int baudrate )
{
  unsigned char x;

  UBRRH = (unsigned char) (baudrate>>8);
  UBRRL = (unsigned char) baudrate;

  UCSRA = (1 << U2X);
  /* Enable UART receiver and transmitter */
  UCSRB = ( ( 1 << RXCIE ) | ( 1 << RXEN ) | ( 1 << TXEN ) | ( 1 << TXCIE ));

  /* Set frame format: 8 data 2stop */
  UCSRC = (1<<URSEL)|(1<<USBS)|(1<<UCSZ1)|(1<<UCSZ0);

  /* Flush receive buffer */
  x = 0;

  USART_RxTail = x;
  USART_RxHead = x;
  USART_TxTail = x;
  USART_TxHead = x;
}