diff --git a/src/uart.c b/src/uart.c
index e98fb64..0c77475 100644
--- a/src/uart.c
+++ b/src/uart.c
@@ -12,29 +12,61 @@
 
 /* http://www.cs.mun.ca/~rod/Winter2007/4723/notes/serial/serial.html */
 
-void uart_init(void) {
+void uart0_init(void)
+{
     UBRR0H = UBRRH_VALUE;
     UBRR0L = UBRRL_VALUE;
-    
 #if USE_2X
     UCSR0A |= _BV(U2X0);
 #else
     UCSR0A &= ~(_BV(U2X0));
 #endif
-
-    UCSR0C = _BV(UCSZ01) | _BV(UCSZ00); /* 8-bit data */ 
-    UCSR0B = _BV(RXEN0) | _BV(TXEN0);   /* Enable RX and TX */    
+    UCSR0C = _BV(UCSZ01) | _BV(UCSZ00); /* 8-bit data */
+    UCSR0B = _BV(RXEN0) | _BV(TXEN0);   /* Enable RX and TX */
 }
 
-void uart_putchar(char c, FILE *stream) {
+void uart3_init(void)
+{
+    UBRR3H = UBRRH_VALUE;
+    UBRR3L = UBRRL_VALUE;
+#if USE_2X
+    UCSR3A |= _BV(U2X3);
+#else
+    UCSR3A &= ~(_BV(U2X3));
+#endif
+    UCSR3C = _BV(UCSZ31) | _BV(UCSZ30); /* 8-bit data */
+    UCSR3B = _BV(TXEN3);   /* Enable RX and TX */
+}
+
+int uart0_putchar(char c, FILE *stream)
+{
+    (void) stream;
+
     if (c == '\n') {
-        uart_putchar('\r', stream);
+        uart0_putchar('\r', stream);
     }
+
     loop_until_bit_is_set(UCSR0A, UDRE0);
     UDR0 = c;
+    return 0;
 }
 
-char uart_getchar(FILE *stream) {
+int uart3_putchar(char c, FILE *stream)
+{
+    (void) stream;
+
+    if (c == '\n') {
+        uart3_putchar('\r', stream);
+    }
+
+    loop_until_bit_is_set(UCSR3A, UDRE3);
+    UDR3 = c;
+    return 0;
+}
+
+int uart0_getchar(FILE *stream)
+{
+    (void) stream;
     loop_until_bit_is_set(UCSR0A, RXC0);
     return UDR0;
 }
diff --git a/src/uart.h b/src/uart.h
index b2c6cde..6667ab1 100644
--- a/src/uart.h
+++ b/src/uart.h
@@ -1,9 +1,12 @@
-void uart_putchar(char c, FILE *stream);
-char uart_getchar(FILE *stream);
+int uart0_putchar(char c, FILE *stream);
+int uart0_getchar(FILE *stream);
 
-void uart_init(void);
+int uart3_putchar(char c, FILE *stream);
+
+void uart0_init(void);
+void uart3_init(void);
 
 /* http://www.ermicro.com/blog/?p=325 */
 
-FILE uart_output = FDEV_SETUP_STREAM(uart_putchar, NULL, _FDEV_SETUP_WRITE);
-FILE uart_input = FDEV_SETUP_STREAM(NULL, uart_getchar, _FDEV_SETUP_READ);
+FILE uart0_io = FDEV_SETUP_STREAM(uart0_putchar, uart0_getchar, _FDEV_SETUP_RW);
+FILE uart3_out = FDEV_SETUP_STREAM(uart3_putchar, NULL, _FDEV_SETUP_WRITE);