#define FOSC 16000000 // Clock Speed
#define BAUD 9600
#define MYUBRR FOSC/16/BAUD-1
#include <avr/io.h>

void USART_Init( unsigned int ubrr)
{
    /*Set baud rate */
    UBRR0H = (unsigned char)(ubrr>>8);
    UBRR0L = (unsigned char)ubrr;
    /* Enable receiver and transmitter */
    UCSR0B = (1<<RXEN0)|(1<<TXEN0);
    /* Set frame format: 8data, 2stop bit */
    UCSR0C = (3<<UCSZ00);
}

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

void main( void )
{
    USART_Init(MYUBRR);
    while (1)
    {
        USART_Transmit(USART_Receive());
    }
}