通讯mqtt

mqtt通讯----python使用
安装：

pip install paho-mqtt

接受消息，先启动

import paho.mqtt.client as mqtt


# 接收消息

def on_connect(client, userdata, flags, rc):
    print("Connected with result code: " + str(rc))


def on_message(client, userdata, msg):
    print(msg.topic + " " + str(msg.payload))


# 创建客户端
client = mqtt.Client()
# 连接调用
client.on_connect = on_connect
# 推送调用
client.on_message = on_message
# ip地址 端口号 最大等待时长
client.connect('broker.emqx.io', 1883, 600)  # 600为keepalive的时间间隔
# 设置订阅主题 fifa
client.subscribe('fifa', qos=0)
client.loop_forever()  # 保持连接

发送消息

import paho.mqtt.client as mqtt


# 发送消息

def on_connect(client, userdata, flags, rc):
    print("Connected with result code: " + str(rc))


def on_message(client, userdata, msg):
    print(msg.topic + " " + str(msg.payload))


# 创建客户端
client = mqtt.Client()
# 连接调用
client.on_connect = on_connect
# 推送调用
client.on_message = on_message
# ip地址 端口号 最大等待时长
client.connect('broker.emqx.io', 1883, 600)  # 600为keepalive的时间间隔
# 发布消息 payload=消息内容
client.publish('fifa', payload='amazing', qos=0)

测试结果：