   delay(15);
 }
 
-void led_heartbeat_missing() {
+void signal_heartbeat_missing() {
   led_red();
   delay(10);
   led_red();


    serial_flush();

    if (incomingByte == 0x42) {
      track_last_heartbeat = millis();
      track_missing_heartbeat = track_last_heartbeat;
      led_heartbeat();
      return last_heartbeat;
    } else {
      return -1;
    }
  } else {
    return 0;

    serial_flush();

    if (incomingByte == 0x108) {
      send_ok();
      signal_heartbeat_ack();
      return 1;
    } else {
      return 0;
