It works

lib/usart.cpp

@@ -0,0 +1,50 @@
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include "usart.h"
+
+namespace usart
+{
+    namespace {
+        static FILE mystdout;
+    }
+    
+    void init( unsigned long baud) {
+        fdev_setup_stream(&mystdout, put_printf, NULL, _FDEV_SETUP_WRITE);
+        stdout = &mystdout;
+        const unsigned int ubrr =  F_CPU/16/baud-1;
+
+        /*Set baud rate */
+        UBRRH = (unsigned char)(ubrr>>8);
+        UBRRL = (unsigned char)ubrr;
+        //Enable receiver and transmitter 
+        UCSRB = (1<<RXEN)|(1<<TXEN);
+        //UCSRB |= (1<< RXCIE)|(1<<TXCIE);
+        /* Set frame format: 8data, 2stop bit */
+        UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
+        sei();
+
+    }
+
+    void put(char data) {
+        /* Wait for empty transmit buffer */
+        while ( !( UCSRA & (1<<UDRE)) )
+        ;
+        /* Put data into buffer, sends the data */
+        UDR = data;
+    }
+
+    char get( void ) {
+        /* Wait for data to be received */
+        while ( !(UCSRA & (1<<RXC)) )
+        ;
+        /* Get and return received data from buffer */
+        return UDR;
+    }       
+   
+    int put_printf(char var, FILE *stream) {
+        put(var);
+        return 0;
+    }
+} // namespace usart
+
+