无需注册PORT=1883# MQTT默认端口号TOPICS=[("sensor/temperature",0),("sensor/humidity",0),("sensor/pressure",0)]# 发布者回调函数defon_connect(client,userdata,flags,rc):print("连接成功,结果代码: {}".format(rc))# 订阅多个主题client.subs
mqttc = mqtt.Client("test") mqttc.on_message = on_message mqttc.on_connect = on_connect mqttc.on_publish = on_publish mqttc.on_subscribe = on_subscribe mqttc.on_log = on_log # 设置账号密码 # mqttc.username_pw_set(username, password=password) mqttc.connect(strBroker, port, 60) ...
一. mqtt概念 MQTT(Message Queuing Telemetry Transport,消息队列遥测传输协议),是一种基于发布/订阅(publish/subscribe)模式的"轻量级"通讯协议,该协议构建于TCP/IP协议上,由IBM在1999年发布 由于物联网的环境是非常特别的,所以MQTT遵循以下设计原则: (1)精简,不添加可有可无的功能; (2)发布/订阅(Pub/Sub)模式...
message是一个描述所有消息参数的MQTTMessage。defon_message(client, userdata, msg):print(msg.topic +" "+str(msg.payload))# 当客户端有日志信息时调用defon_log(client, obj, level, string):print("Log:"+ string)# 实例化client = mqtt.Client()# client.username_pw_set("admin", "password")# ...
首先,我们需要安装并导入paho-mqtt库,这是一个流行的Python MQTT客户端库。你可以通过pip install paho-mqtt来安装它。 python import paho.mqtt.client as mqtt 创建MQTT客户端实例: 使用paho.mqtt.client.Client类来创建一个MQTT客户端实例。你可以传递一个客户端ID作为参数,如果不传递,系统会自动生成一个。 py...
(client_id,protocol=protocol)self.myClient.on_connect=self.on_connectself.myClient.on_message=self.on_messageself.myClient.on_publish=self.on_publish# self.myClient.connect_async(mqtt_host, mqtt_port, mqtt_keepalive) # 异步数据发送self.myClient.connect(mqtt_host,mqtt_port,mqtt_keepalive)# ...
mqttc.on_message = on_message mqttc.on_connect = on_connect mqttc.on_publish = on_publish mqttc.on_subscribe = on_subscribe mqttc.on_log = on_log # 设置账号密码(如果需要的话) #mqttc.username_pw_set(username, password=password) mqttc.connect(strBroker, port, 60) mqttc.subscribe(to...
def on_subscribe(client, userdata, mid, granted_qos): print("On Subscribed: qos = %d" % granted_qos) # 失去连接 def on_disconnect(client, userdata, rc): if rc != 0: print("Unexpected disconnection %s" % rc) client = mqtt.Client(client_id) ...
编写消息回调函数on_message,该函数将在客户端从 MQTT Broker 收到消息后被调用,在该函数中我们将打印出订阅的 topic 名称以及接收到的消息内容。 def subscribe(client: mqtt_client): def on_message(client, userdata, msg): print(f"Received `{msg.payload.decode()}` from `{msg.topic}` topic") ...
这意味着 MQTT 客户端接收发布到此主题过滤器的所有消息。 主题过滤器中所谓的通配符(“#”)包括所有以“encyclopedia/”开头的主题。 on_subscribe 回调作为订阅工作的保证。 然后代码发布一条消息,并在收到消息时将其打印到终端。 由于 on_message 回调,它会打印消息,当消息进入时会触发该消息。 # subscribe to...