[英]Trying to send one message via MQTT and sleep for 5 seconds
我目前正在尝试通过有效的 MQTT 协议发送消息。 我使用树莓派和振动传感器作为触发消息发送的手段。 一开始我会触摸传感器,它会立即发送大量消息,这是我不希望发生的。 所以我试着让它在检测到振动后休眠 5 秒钟。 但现在它检测到一种振动,然后不会检测到另一种振动,但不会停止文件的运行。 我能让它再次检测到振动的唯一方法是再次运行文件。 这是我尝试的两种方法:
import time
from grove.gpio import GPIO
import paho.mqtt.client as mqttClient
class GrovePiezoVibrationSensor(GPIO):
def __init__(self, pin):
super(GrovePiezoVibrationSensor, self).__init__(pin, GPIO.IN)
self._on_detect = None
@property
def on_detect(self):
return self._on_detect
@on_detect.setter
def on_detect(self, callback):
if not callable(callback):
return
if self.on_event is None:
self.on_event = self._handle_event
self._on_detect = callback
def _handle_event(self, pin, value):
if value:
if callable(self._on_detect):
self._on_detect()
time.sleep(5000)
Grove = GrovePiezoVibrationSensor
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
global Connected #Use global variable
Connected = True #Signal connection
else:
print("Connection failed")
Connected = False #global variable for the state of the connection
broker_address= "hairdresser.cloudmqtt.com"
port = 15767
user = "kprpjfue"
password = "1fIq2_CIwHZj"
client = mqttClient.Client("Python") #create new instance
client.username_pw_set(user, password=password) #set username and password
client.on_connect= on_connect
client.loop_start()
client.connect(broker_address, port=port)
def main():
from grove.helper import SlotHelper
sh = SlotHelper(SlotHelper.GPIO)
pin = sh.argv2pin()
pir = GrovePiezoVibrationSensor(pin)
def callback():
print('Detected.')
value = 'detected'
client.publish("sensor/Temp", value)
pir.on_detect = callback
while True:
time.sleep(5000)
if __name__ == '__main__':
main()
while Connected != True: #Wait for connection
time.sleep(0.1)
import time
from grove.gpio import GPIO
import paho.mqtt.client as mqttClient
class GrovePiezoVibrationSensor(GPIO):
def __init__(self, pin):
super(GrovePiezoVibrationSensor, self).__init__(pin, GPIO.IN)
self._on_detect = None
@property
def on_detect(self):
return self._on_detect
@on_detect.setter
def on_detect(self, callback):
if not callable(callback):
return
if self.on_event is None:
self.on_event = self._handle_event
self._on_detect = callback
def _handle_event(self, pin, value):
if value:
if callable(self._on_detect):
self._on_detect()
time.sleep(5000)
Grove = GrovePiezoVibrationSensor
def on_connect(client, userdata, flags, rc):
if rc == 0:
print("Connected to broker")
global Connected #Use global variable
Connected = True #Signal connection
else:
print("Connection failed")
Connected = False #global variable for the state of the connection
broker_address= "hairdresser.cloudmqtt.com"
port = 15767
user = "kprpjfue"
password = "1fIq2_CIwHZj"
client = mqttClient.Client("Python") #create new instance
client.username_pw_set(user, password=password) #set username and password
client.on_connect= on_connect
client.connect(broker_address, port=port)
def main():
from grove.helper import SlotHelper
sh = SlotHelper(SlotHelper.GPIO)
pin = sh.argv2pin()
pir = GrovePiezoVibrationSensor(pin)
def callback():
print('Detected.')
value = 'detected'
client.publish("sensor/Temp", value)
pir.on_detect = callback
while True:
time.sleep(5000)
client.loop()
if __name__ == '__main__':
main()
while Connected != True: #Wait for connection
time.sleep(0.1)
正如您在句柄事件方法中的 if callable 下看到的那样,我告诉我说的是 time.sleep(5000)。 我把这个放在错误的地方了吗?
您尚未启动 MQTT 客户端网络循环,因此它将无法接收消息或发送大于 MTU 的消息。
在保持活动期后,您也将断开连接。
在调用client.connect()
client.loop_start()
)
或在 main 循环中的time.sleep(5000)
之后插入client.loop()
,最好将其设置为 1000 以使客户端循环至少每秒运行一次。
在回调中添加睡眠通常是一个坏主意,因为它不会阻止事件被触发,只会延迟它们,因为它们只会排队直到睡眠超时。
您应该在发送 MQTT 消息之后在第一个事件上设置一个标志,然后您可以使用 main 中的 While True 循环使该消息过期。 如果在标志仍然设置的情况下出现新事件,那么您只需不发送另一条 MQTT 消息。
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