有没有人为此找到一个优雅的解决方案？
用户有一个 BLE Puck.js 按钮，当按钮被按下时，它会将 MQTT 消息发送到 Node-Red。
Node-Red 场景将收到来自冰球的按钮按下事件，并将启动 30 秒计时器。 [First Pass Works] 定时器超时后向指定用户发送短信。
这适用于标准触发器。收到消息后，我启动 LED 闪烁并等待 30 秒，然后发送停止闪烁的 LED 并发送 SMS。
但是... 30 秒延迟的整个想法是，我们让用户有机会通过在延迟有效时再次按下来取消他们的请求。在这种情况下，我们需要关闭闪烁的 LED，然后继续等待。
这部分我遇到了一些麻烦。它基本上是一个状态机，接收到消息时执行的操作取决于机器的当前状态。
我正在尝试使用上下文变量来解决这个问题，但结果并不干净。
我已经让它与编码到 Puck.js 按钮中的状态机一起工作，但我正在尝试另一种设计，而是将它编码到 Node-Red 流中。
有什么想法吗？ 谢谢
【问题讨论】：
最简单的方法是使用几个更改节点来翻转上下文变量中的状态，并使用一个切换节点对其进行操作。我使用注入节点代替节点中的 MQTT 只是为了使示例自包含。
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【讨论】：