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MQTT 插件

MQTT broker 需要支持 wss(websockets) 协议, 才能在Scratch里连接它

CodeLab合作伙伴英荔教育为CodeLab社区用户提供一个免费 MQTT broker:

  • url: mqtt.aimaker.space
  • 默认用户名/密码: guest/test
  • tcp port: 1883
  • tls port 8883
  • websockets port: 8084

Demo

scratch client

scratch demo

python client

基于 paho-mqtt

import paho.mqtt.client as mqtt

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    # print("Connected with result code "+str(rc))
    if rc == 0:
        print('已连接')
    else:
        print('连接出错！')
    # Subscribing in on_connect() means that if we lose the connection and
    # reconnect then subscriptions will be renewed.
    client.subscribe("test")

# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
    print(msg.topic+" "+str(msg.payload))

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.username_pw_set('guest', 'test')

client.connect("mqtt.aimaker.space", 1883, 60)

# Blocking call that processes network traffic, dispatches callbacks and
# handles reconnecting.
# Other loop*() functions are available that give a threaded interface and a
# manual interface.
client.loop_forever() # client.loop_start() 是非阻塞的

MicroBlocks demo

MicroBlocks demo

Snap! Demo

Snap! Demo

cli demo

先安装 mosquitto

pub: mosquitto_pub -h mqtt.aimaker.space -u guest -P test -t 'scratch' -m 'hi --from cli'

sub: mosquitto_sub -h mqtt.aimaker.space -u guest -P test -t "cli"

参考