// Update is called once per frame
    void Update()
    {
        a_time += Time.deltaTime;
        if (Time.time - u_time > updateTime)
        {
            GameObject[] zombies = GameObject.FindGameObjectsWithTag("zombie");
            if (zombies.Length > 0)
            {
                u_time = Time.time;
                print("Update Zombie");
                serialPort.UpdateZombie();
            }
        }

        if (Time.time - time > spawnTime)
        {
            time = Time.time;
            GameObject       obj = Instantiate(zombies, new Vector3(3, 0, 27f), Quaternion.identity) as GameObject;
            ZombieController zc  = obj.GetComponent <ZombieController>();
            //zc.queue = queue;
            zc.SetID(zombieCount);
            zc.SetSerialPort(serialPort);
            obj.transform.localScale = new Vector3(35.0f, 35.0f, 35.0f);
            obj.tag = "zombie";
            //queue.Enqueue(obj);
            print("Spawn Zombie" + zombieCount);
            zombieCount++;
            serialPort.SpawnZombie(zombieCount);
        }
        if (Input.GetMouseButtonDown(0))
        {
            BuildBlock(0, 0);
        }
        if (Input.GetMouseButtonDown(1))
        {
            ShootArrow();
        }
    }