     trace << dev << endl;
   } while (last != OWI::Driver::LAST);
   trace << endl;
+  ledPin.toggle();
   
   // Sleep awhile before checking again
   SLEEP(2);

void loop()
{
  // Search for alarms
  OWI::Driver dev(&owi);
  int8_t last = OWI::Driver::FIRST;
  do {

// Use the builtin led for a heartbeat
OutputPin ledPin(Board::LED);

// One-wire pin
#if defined(__ARDUINO_TINY__)
OWI owi(Board::D1);
#else
