是时候从 mqtt 负载打开 on/off 屏幕了

Question

我是 python 的新手，仍在学习中，所以请对我温柔点。我有我的 python 脚本，它订阅了一个 MQTT 主题并接收了一个代码。

如果有效载荷等于该代码，那么它将设置打开显示器的计时器。时间过去后，显示将关闭，直到有效负载再次等于之前描述的相同代码。

这是我的代码：

    import paho.mqtt.client as mqttClient
    import time
    from subprocess import call
    from time import sleep


    def on_connect(client, userdata, flags, rc):
    #    print("Connected with result code "+str(rc))
        client.subscribe("home/OpenMQTTGateway/433toMQTT")
    #def on_message(client, userdata, msg):
    #    if msg.topic == 'home/OpenMQTTGateway/433toMQTT':
    #        print(str(msg.payload))


def on_message(client, userdata, msg):
    global myGlobalMessagePayload
    if msg.topic == 'home/OpenMQTTGateway/433toMQTT':
        myGlobalMessagePayload = msg.payload

    timeUntilDisplayOff = 240

    timer = timeUntilDisplayOff

    while True:

        if msg.payload == '1381683':
                timer = timeUntilDisplayOff
                print ("Motion detected! Setting timer to " + str(timer) + " seconds.")


            if timer > 0:
                    if timer % 10 == 0:
                            print ("Timer: " + str(timer) + " seconds")
                    timer -= 1

            elif timer == 0:
                    call(['vcgencmd', 'display_power', '0'])

                    print ("Timer is 0. Display turned off. Waiting for motion...")
                    # display is now off. we wait for motion and turn it on
                    myGlobalMessagePayload == '1381683'
                    call(['vcgencmd', 'display_power', '1'])
                    timer = timeUntilDisplayOff

            sleep(1)

问题：

当我运行我的代码时，我收到一条错误消息：

Traceback (most recent call last):
  File "test2.py", line 26, in <module>
    if msg.payload == '1381683':
NameError: name 'msg' is not defined

我还使用通用代码重复了该过程，即在 # display is now off. we wait for motion and turn it on 之后接近尾声时，它看起来正确吗？或者可以做得更好吗？

谢谢

更新：

感谢@blt，我整理了我的代码。但是，当 msg.payload 匹配“1381683”时，我的代码会继续循环。我得到以下信息：

Motion detected! Setting timer to 240 seconds.
Timer: 240 seconds
Motion detected! Setting timer to 240 seconds.
Timer: 240 seconds
Motion detected! Setting timer to 240 seconds.
Timer: 240 seconds

上面一直在循环...

Answer 1

缩进在 python 中很重要。

您需要将以下块缩进一级：

timeUntilDisplayOff = 1800

timer = timeUntilDisplayOff

while True:

否则本节后面的代码将不会在范围内包含 msg 变量（因此会出现错误）。

所以on_message函数的前半部分是：

def on_message(client, userdata, msg):
    global myGlobalMessagePayload
    if msg.topic == 'home/OpenMQTTGateway/433toMQTT':
        myGlobalMessagePayload = msg.payload

    timeUntilDisplayOff = 1800

    timer = timeUntilDisplayOff

    while True:

        if msg.payload == '1381683':
                timer = timeUntilDisplayOff
                print ("Motion detected! Setting timer to " + str(timer) + " seconds.")

是时候从 mqtt 负载打开 on/off 屏幕了

time to turn on/off screen from mqtt payload

python

counter

timer

python-multithreading

mqtt