MQTT

案例程序

连接MQTT服务器, 实现订阅和主题消息发布。

from m5stack import *
from m5ui import *
from uiflow import *
from m5mqtt import M5mqtt
import time

setScreenColor(0x222222)

def fun__dev_sub_(topic_data):
  # global params
  print('topic: /dev/sub received:')
  print(topic_data)
  pass

m5mqtt = M5mqtt('id_123456', 'broker.emqx.io', 1883, 'user_123456', 'pwd_123456', 20)
m5mqtt.subscribe(str('/dev/sub'), fun__dev_sub_)
print('mqtt connecting....')
m5mqtt.set_last_will(str('/dev/last_will'),str('device disconnect'))
m5mqtt.start()
print('mqtt connected')
while True:
  m5mqtt.publish(str('/dev/pub'), str('Hello'), 0)
  wait(10)
  wait_ms(2)

功能说明

m5mqtt = M5mqtt('id_123456', 'broker.emqx.io', 1883, 'user_123456', 'pwd_123456', 20)

• 初始化MQTT客户端信息

m5mqtt = M5mqtt('id_123456', 'broker.emqx.io', 1883, 'user_123456', 'pwd_123456', 20, ssl = True, ssl_params = {'key': "/flash/res/certificate.pem.crt", 'cert': "/flash/res/private.pem.key"})

• 若希望初始化MQTTS连接，可启用SSL选项，并通过+号导入客户端证书到设备。

m5mqtt.set_last_will(str('/dev/last_will'),str('device disconnect'))

• 设置MQTT客户端遗嘱(last will)信息，当客户端异常断开时，服务器将会发布该信息。注: last will信息需要在mqtt start连接前进行配置。

m5mqtt.start()

• 开始连接MQTT服务器

m5mqtt.publish(str('/dev/pub'), str('Hello'), 0)

• 发布指定topic信息，以及配置信息QoS级别

def fun__dev_sub_(topic_data):
  print(topic_data)
  pass

m5mqtt.subscribe(str('/dev/sub'), fun__dev_sub_)

• 订阅主题信息，并配置对应的回调函数，当接收到该主题消息将自动执行。