   switch(event)
   {
     case ACI_EVT_DEVICE_STARTED:
-      Serial.println(F("Advertising started"));
+      sprintln(F("Advertising started"));
       break;
     case ACI_EVT_CONNECTED:
-      Serial.println(F("Connected!"));
+      sprintln(F("Connected!"));
       break;
     case ACI_EVT_DISCONNECTED:
-      Serial.println(F("Disconnected or advertising timed out"));
+      sprintln(F("Disconnected or advertising timed out"));
       break;
     default:
       break;

/**************************************************************************/
void rxCallback(uint8_t *buffer, uint8_t len)
{
  Serial.print(F("Received "));
  Serial.print(len);
  Serial.print(F(" bytes: "));
  
  if(commandInterpreter.interpretCommand(buffer, len)) // check if command can be interpreted
      return;  // do not echo if command was a success

  
  // print buffer in HEX to the console:
  /*
  print(F(" ["));
  for(int i=0; i<len; i++)
  {
      print(" 0x"); print((char)buffer[i], HEX); 
  }
  println(F(" ]"));
  */
}

