interrupt driven sending

src/uartdrv.c

@@ -21,9 +21,10 @@ void uartdrvInit() {
   UCSRB = (1 << TXEN);
   //        8 data bit, no parity, 1 stop bit
   UCSRC = (1 << UCSZ1) | (1 << UCSZ0);
-  //        115200 Baud @ 16MHz
+  //        2400 Baud @ 16MHz
   UBRRL = 0xa0;
   UBRRH = 0x01;;
+
   FILE *mystdout = fdevopen(uartdrvPutchar, NULL);
   stdout = mystdout;
 }