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#include <avr/io.h>

#include <stdio.h>
#include "uart.h"

static int USART0_Transmit( char data )
{
        /* Wait for empty transmit buffer */
//      while ( !(UCSR0A & (1<<UDRE0)) );
        loop_until_bit_is_set(UCSR0A, UDRE0);

        /* Start transmittion */
        UDR0 = data;

        return 0;
}

static int USART0_Receive( void )
{
        char c;
        /* Wait for incomming data */
//      while ( !(UCSR0A & (1<<RXC0)) );
        loop_until_bit_is_set(UCSR0A, RXC0);

        c = UDR0;
        /* Echo */
        loop_until_bit_is_set(UCSR0A, UDRE0);
        UDR0 = c;
        if(c == '\r') {
        loop_until_bit_is_set(UCSR0A, UDRE0);
        UDR0 = '\n';
        }
        /* Return the data */
        return c;
}

void initUART(void){
        /* set baud rate */
        UBRR0H = (unsigned char) (UART_BAUD_SELECT>>8);
        UBRR0L = (unsigned char) UART_BAUD_SELECT;

        /* Enable UART receiver and transmitter */
        UCSR0A = ( 1 << U2X0 );
        UCSR0B = ( ( 1 << RXEN0 ) | ( 1 << TXEN0 ) );

        fdevopen((void*)USART0_Transmit, (void*)USART0_Receive);
}