diff -r dfe67409fbcd -r ec42f36d8614 src/timer.c
--- a/src/timer.c	Thu Apr 03 20:25:12 2014 +0300
+++ b/src/timer.c	Thu Apr 03 22:24:46 2014 +0300
@@ -69,8 +69,10 @@
  */
 char timer_sleep (int cycles)
 {
-    // set timer
-    timer1_start(cycles);
+    if (cycles) {
+        // set timer
+        timer1_start(cycles);
+    }
 
     // sleep
     // TODO: PRR
@@ -88,14 +90,14 @@
     // cleanup
     SMCR = 0;
     
-    if (tbi(&TIMER_FLAGS, TIMER1_BUSY)) {
+    if (cycles && !tbi(&TIMER_FLAGS, TIMER1_BUSY)) {
+        // timeout
+        return 1;
+    } else {
         timer1_stop();
 
         // interrupt
         return 0;
-    } else {
-        // timeout
-        return 1;
     }
 }