#include <avr\io.h>
#include <util\delay.h>
#include <stdlib.h>
//#include <avr\interrupt.h>    

void USART_Transmit( unsigned char data )
{
// Wait for empty transmit buffer
while ( !( UCSR0A & (1<<UDRE0)) )
;
// Put data into buffer, sends the data
UDR0 = data;
}

unsigned char USART_Receive( void )
{
/* Wait for data to be received */
while ( !(UCSR0A & (1<<RXC0)) )
;
/* Get and return received data from buffer */
return UDR0;
}

void USART_Init( unsigned int baud )
{
// Set baud rate
UBRR0H = (unsigned char)(baud>>8);
UBRR0L = (unsigned char)baud;
// Enable receiver and transmitter
UCSR0B = (1<<RXEN0)|(1<<TXEN0);
// Set frame format: 8data, 1stop bit
UCSR0C = (0<<USBS0)|(3<<UCSZ00);
}

int main (void)
{

DDRB=0x00;

USART_Init(9600);

while(1)
    {
    //USART_Transmit(USART_Receive());
    USART_Transmit('T');
    PORTB=0x00;
    _delay_ms(500);
    PORTB=0xFF;
    _delay_ms(500);
    }
}