Printf example avr

#define F_CPU 16000000UL    // 1MHz
#include <avr/io.h>
#include <stdio.h>
#include <util/delay.h>


void init_uart(void);
static int uart_putc(char data, FILE *stream);

static FILE mystdout = FDEV_SETUP_STREAM(uart_putc, NULL, _FDEV_SETUP_WRITE);


int main(void)
{

    stdout=&mystdout;
    DDRB |= (1<<PB1);

    init_uart();

    while(1)
    {
        if (!(PINB & (1<<PB0)))
        {
            printf("AABBCC\r\n");
            PORTB |= (1<<PB1);
            _delay_ms(500);
            PORTB &= ~(1<<PB1);
            while (!(PINB & (1<<PB0))){}
        }

    }
}

void init_uart(void){
    UBRR1 = 103;
    UCSR1B = (1<<RXEN1)|(1<<TXEN1);
}

static int uart_putc(char data, FILE *stream){
    if (data == '\n') uart_putc('\r', stream);
while (!(UCSR1A & (1<<UDRE1))){};
UDR1 = data;
return 0;
}