  */
 void backlight_timeout(uint64_t timeout)
 {
+  if(backlight_on_time == -1)
+    return;
+
   uint64_t delta_t = millis() - backlight_on_time;
   if(delta_t > timeout)
   {

  return true;
}

uint64_t backlight_on_time;

/**
 * Sets the state of the backlight.

 */
void process_backlight_message(char *data)
{
  char msg_type;
  int backlight_mode;
  sscanf(data, "%c|%d", &msg_type, &backlight_mode);

  if(msg_type != 'B')
    return;

#ifdef SERIAL_DEBUG
  SERIAL.println("Got backlight message:");
  SERIAL.print("- Mode: ");
  SERIAL.println(backlight_mode);
#endif

  set_backlight((backlightmode_t) backlight_mode);
}
