Re: Where is the error (stdout)

>
> void uart_putchar(char c, FILE *stream)
> {
>  if (c == '\n')
> uart_putchar('\r', stream);
>  loop_until_bit_is_set(UCSRA, UDRE);
>  UDR = c;
>  return ;
> }
>
I suspect it's because your returning a void instead of an int,

Here is some code that I used to test stdio on avrlibc ( atmega128 )

which compiles fine with gcc 5.4.0


static int uart_putchar(char c, FILE *stream)
{
     if (c == '\n')
         uart_putchar('\r', stream);
     loop_until_bit_is_set(UCSR0A, UDRE);
     UDR0 = c;
     return 0;
}




Cheers

Colin