[嵌入式]通过python实现MQTT发布和订阅

一、安装paho-mqtt

1、通过命令安装

pip install paho-mqtt

二、实现MQTT发布和订阅

1、发布消息

from paho.mqtt import client as mqtt


mqttClient = mqtt.Client()


# 连接MQTT服务
def mqtt_connect():
    MQTTHOST = "192.168.1.150"  # MQTT服务器地址
    MQTTPORT = 1883  # MQTT端口
    mqttClient.connect(MQTTHOST, MQTTPORT, 60)  # 超时时间为60秒
    mqttClient.loop_start()


# 发布消息
def mqtt_publish():
    '''发布一个主题为'mqtt/demo',内容为'Demo text'的信息,服务质量为 2的消息'''
    mqtt_connect()
    text = "Demo text"
    mqttClient.publish('mqtt/demo', text, 2)


if __name__ == '__main__':
    mqtt_publish()

2、订阅消息

from paho.mqtt import client as mqtt

mqttClient = mqtt.Client()


# 连接MQTT服务
def mqtt_connect():
    MQTTHOST = "192.168.1.150"  # MQTT服务器地址
    MQTTPORT = 1883  # MQTT端口
    mqttClient.connect(MQTTHOST, MQTTPORT, 60)  # 超时时间为60秒
    mqttClient.loop_start()


# 消息处理函数
def on_message_come(lient, userdata, msg):
    # print(msg.topic + ":" + str(msg.payload))
    print("主题:"+msg.topic+" 消息:"+str(msg.payload.decode('utf-8')))


# subscribe 消息
def on_subscribe():
    mqttClient.subscribe("mqtt/demo", 2)
    mqttClient.on_message = on_message_come  # 消息到来处理函数


def run():
    mqtt_connect()
    on_subscribe()
    while True:
        pass


if __name__ == '__main__':
    run()