Code:
#include <stdio.h>
#include <avr/io.h>


int PutChar(char c);

int main(void)
{
	float test=5.3;


	// USART initialization
	// Communication Parameters: 8 Data, 1 Stop, No Parity
	// USART Receiver: Off
	// USART Transmitter: On
	// USART Mode: Asynchronous
	// USART Baud rate: 9600

	UCSRA=0x00;
	UCSRB=0x08;
	UCSRC=0x86;
	UBRRH=0x00;
	UBRRL=0x17;
	

	fdevopen(PutChar,NULL,0);
	while(1)
	{
		printf("%f\n\r",test);
	}
	return 0;
}


int PutChar(char c)
{
	while ( !( UCSRA & (1<<UDRE)) );
	UDR=c;
	return 0;
}