--- a/src/hello.c	Thu Apr 03 19:44:53 2014 +0300
+++ b/src/hello.c	Thu Apr 03 20:25:12 2014 +0300
@@ -11,24 +11,29 @@
 
     // LED
     sbi(&DDRB, DDB5);
-    serial_enable();
 
     sei();
 
     // blink
     char c = 'X';
-    short timeout = 1000;
+    short timeout = 8000;
     short delta = 10;
 
     while (true) {
-        serial_write(c);
-
-        // bitflip
+        // toggle
         xbi(&PORTB, PORTB5);
         
-        //timer_sleep(timeout);
-        //timeout += delta;
+        // sleep
+        if (timer_sleep(timeout)) {
+            c = '.';
+
+        } else if ((c = serial_read())) {
+            // got serial data
+        } else {
+            c = '?';
+        }
         
-        c = serial_read();
+        // output...
+        serial_write(c);
     }
 }