   if (isSource) {
     if (!digitalRead(button2pin)) {
       if(SERIAL_DEBUG) Serial.println("alert");
-      char c = ALERT; 
+      char c = ALERT;
       for (int i=0; i<NUM_CONN; i++) bus[i]->write(c);
     }
   }
-  
+
   // check all lines for incoming data
   for (int i=0;i<NUM_CONN;i++) if(bus[i]->available()) {
     char c = bus[i]->read();

        break;
      case DROPPING_CONNECTOR: // some connector in the network is dropped
        // relax alert state and timer
        removeTimer(alertTimer);
        alertState = false;
        // propagate signal though network
        for (int j=0; j<NUM_CONN; j++) if (j!=i) bus[j]->write(c);
        break;
      default: // energy is received
        if (!isSource) {
          if (c<distanceToSource[i]+1) distanceToSource[i] = c+1;
          // if we are not connected and energy was received start timer to process energy 
          // (hopefully this does enhances asynchronous updating between the nodes)
          if (shortestDistanceToSource == 99) addTimer(10, processEnergy);
        }
    }
  }
  
  // update timed processes
  handleTimers();
}


#define SERIAL_DEBUG true

#define DROPPING_CONNECTOR 254
#define ALERT 255

