NodeMCU学习（九）--连接OneNET物联网平台

布满荆棘的人生 2022-10-24 15:25 204阅读 0赞

# 1、OneNET平台介绍 #

OneNET是中国移动打造的高效、稳定、安全的物联网开放平台。OneNET支持适配各种网络环境和协议类型，可实现各种传感器和智能硬件的快速接入，提供丰富的API和应用模板以支撑各类行业应用和智能硬件的开发，有效降低物联网应用开发和部署成本，满足物联网领域设备连接、协议适配、数据存储、数据安全以及大数据分析等平台级服务需求。

关于平台详细的介绍，以及使用的方法，可以查看[《OneNET物联网平台介绍》][OneNET]进行了解。

# 2、MQTT协议 #

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。MQTT最大优点在于，可以以极少的代码和有限的带宽，为连接远程设备提供实时可靠的消息服务。做为一种低开销、低带宽占用的即时通讯协议，使其在物联网、小型设备、移动应用等方面有较广泛的应用。

MQTT协议就是通信双方的一个约定，即，表示第1位传输的什么、第2位传输的什么……。在`MQTT`协议中，一个`MQTT`数据包由：`固定头（Fixed header）`、 `可变头（Variable header）`、 `消息体（payload）`三部分构成。

**数据包结构**

*  `固定头（Fixed header）`，存在于所有`MQTT`数据包中，表示数据包类型及数据包的分组类标识
 *  `可变头（Variable header）`，存在于部分`MQTT`数据包中，数据包类型决定了可变头是否存在及其具体内容
 *  `消息体（Payload）`，存在于部分`MQTT`数据包中，表示客户端收到的具体内容

关于MQTT协议相关介绍可以参考一下博客：

[《MQTT协议--MQTT协议简介及原理》 ][MQTT_--MQTT]

[《MQTT协议--MQTT协议解析》][MQTT_--MQTT 1]

# 3、连接平台所需的API #

## 3.1、WiFi有关的API ##

### unction reference ###

The NodeMCU WiFi control is spread across several tables:

*  [`wifi`][wifi] for overall WiFi configuration
 *  [`wifi.sta`][wifi.sta] for station mode functions
 *  [`wifi.ap`][wifi.ap] for wireless access point (WAP or simply AP) functions
 *  [`wifi.ap.dhcp`][wifi.ap.dhcp] for DHCP server control
 *  [`wifi.eventmon`][wifi.eventmon] for wifi event monitor
 *  [`wifi.monitor`][wifi.monitor] for wifi monitor mode

<table> 
 <tbody> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetchannel" rel="nofollow">wifi.getchannel()</a></td> 
   <td>Gets the current WiFi channel.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetcountry" rel="nofollow">wifi.getcountry()</a></td> 
   <td>Get the current country info.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetdefaultmode" rel="nofollow">wifi.getdefaultmode()</a></td> 
   <td>Gets default WiFi operation mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetmode" rel="nofollow">wifi.getmode()</a></td> 
   <td>Gets WiFi operation mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetphymode" rel="nofollow">wifi.getphymode()</a></td> 
   <td>Gets WiFi physical mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifinullmodesleep" rel="nofollow">wifi.nullmodesleep()</a></td> 
   <td>Configures whether or not WiFi automatically goes to sleep in NULL_MODE.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiresume" rel="nofollow">wifi.resume()</a></td> 
   <td>Wake up WiFi from suspended state or cancel pending wifi suspension.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisetcountry" rel="nofollow">wifi.setcountry()</a></td> 
   <td>Set the current country info.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisetmode" rel="nofollow">wifi.setmode()</a></td> 
   <td>Configures the WiFi mode to use.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisetphymode" rel="nofollow">wifi.setphymode()</a></td> 
   <td>Sets WiFi physical mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisetmaxtxpower" rel="nofollow">wifi.setmaxtxpower()</a></td> 
   <td>Sets WiFi maximum TX power.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistartsmart" rel="nofollow">wifi.startsmart()</a></td> 
   <td>Starts to auto configuration, if success set up SSID and password automatically.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistopsmart" rel="nofollow">wifi.stopsmart()</a></td> 
   <td>Stops the smart configuring process.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisuspend" rel="nofollow">wifi.suspend()</a></td> 
   <td>Suspend Wifi to reduce current consumption.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistaautoconnect" rel="nofollow">wifi.sta.autoconnect()</a></td> 
   <td>Auto connects to AP in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistachangeap" rel="nofollow">wifi.sta.changeap()</a></td> 
   <td>Select Access Point from list returned by wifi.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistaclearconfig" rel="nofollow">wifi.sta.clearconfig()</a></td> 
   <td>Clears the currently saved WiFi station configuration, erasing it from the flash.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistaconfig" rel="nofollow">wifi.sta.config()</a></td> 
   <td>Sets the WiFi station configuration.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistaconnect" rel="nofollow">wifi.sta.connect()</a></td> 
   <td>Connects to the configured AP in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistadisconnect" rel="nofollow">wifi.sta.disconnect()</a></td> 
   <td>Disconnects from AP in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetap" rel="nofollow">wifi.sta.getap()</a></td> 
   <td>Scans AP list as a Lua table into callback function.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetapindex" rel="nofollow">wifi.sta.getapindex()</a></td> 
   <td>Get index of current Access Point stored in AP cache.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetapinfo" rel="nofollow">wifi.sta.getapinfo()</a></td> 
   <td>Get information of APs cached by ESP8266 station.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetbroadcast" rel="nofollow">wifi.sta.getbroadcast()</a></td> 
   <td>Gets the broadcast address in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetconfig" rel="nofollow">wifi.sta.getconfig()</a></td> 
   <td>Gets the WiFi station configuration.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetdefaultconfig" rel="nofollow">wifi.sta.getdefaultconfig()</a></td> 
   <td>Gets the default WiFi station configuration stored in flash.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagethostname" rel="nofollow">wifi.sta.gethostname()</a></td> 
   <td>Gets current station hostname.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetip" rel="nofollow">wifi.sta.getip()</a></td> 
   <td>Gets IP address, netmask, and gateway address in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetmac" rel="nofollow">wifi.sta.getmac()</a></td> 
   <td>Gets MAC address in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistagetrssi" rel="nofollow">wifi.sta.getrssi()</a></td> 
   <td>Get RSSI(Received Signal Strength Indicator) of the Access Point which ESP8266 station connected to.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistasetaplimit" rel="nofollow">wifi.sta.setaplimit()</a></td> 
   <td>Set Maximum number of Access Points to store in flash.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistasethostname" rel="nofollow">wifi.sta.sethostname()</a></td> 
   <td>Sets station hostname.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistasetip" rel="nofollow">wifi.sta.setip()</a></td> 
   <td>Sets IP address, netmask, gateway address in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistasetmac" rel="nofollow">wifi.sta.setmac()</a></td> 
   <td>Sets MAC address in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistasleeptype" rel="nofollow">wifi.sta.sleeptype()</a></td> 
   <td>Configures the WiFi modem sleep type to be used while station is connected to an Access Point.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifistastatus" rel="nofollow">wifi.sta.status()</a></td> 
   <td>Gets the current status in station mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapconfig" rel="nofollow">wifi.ap.config()</a></td> 
   <td>Sets SSID and password in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapdeauth" rel="nofollow">wifi.ap.deauth()</a></td> 
   <td>Deauths (forcibly removes) a client from the ESP access point by sending a corresponding IEEE802.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetbroadcast" rel="nofollow">wifi.ap.getbroadcast()</a></td> 
   <td>Gets broadcast address in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetclient" rel="nofollow">wifi.ap.getclient()</a></td> 
   <td>Gets table of clients connected to device in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetconfig" rel="nofollow">wifi.ap.getconfig()</a></td> 
   <td>Gets the current SoftAP configuration.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetdefaultconfig" rel="nofollow">wifi.ap.getdefaultconfig()</a></td> 
   <td>Gets the default SoftAP configuration stored in flash.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetip" rel="nofollow">wifi.ap.getip()</a></td> 
   <td>Gets IP address, netmask and gateway in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapgetmac" rel="nofollow">wifi.ap.getmac()</a></td> 
   <td>Gets MAC address in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapsetip" rel="nofollow">wifi.ap.setip()</a></td> 
   <td>Sets IP address, netmask and gateway address in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapsetmac" rel="nofollow">wifi.ap.setmac()</a></td> 
   <td>Sets MAC address in AP mode.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapdhcpconfig" rel="nofollow">wifi.ap.dhcp.config()</a></td> 
   <td>Configure the dhcp service.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapdhcpstart" rel="nofollow">wifi.ap.dhcp.start()</a></td> 
   <td>Starts the DHCP service.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapdhcpstop" rel="nofollow">wifi.ap.dhcp.stop()</a></td> 
   <td>Stops the DHCP service.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifieventmonregister" rel="nofollow">wifi.eventmon.register()</a></td> 
   <td>Register/unregister callbacks for WiFi event monitor.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifieventmonunregister" rel="nofollow">wifi.eventmon.unregister()</a></td> 
   <td>Unregister callbacks for WiFi event monitor.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifieventmonreason" rel="nofollow">wifi.eventmon.reason</a></td> 
   <td>Table containing disconnect reasons.</td> 
  </tr> 
 </tbody> 
</table>

###  3.1.1 所要用到的WiFi相关API ###

（1）wifi.setmode()

（2）wifi.sta.config()

（3）wifi.sta.connect()

关于API的使用方法，可以参考博客[《NodeMCU学习（六）--WiFi》][NodeMCU_--WiFi]，也可以参考[官网][Link 1]对API的说明。

## 3.2、MQTT有关的API ##

The client adheres to version 3.1.1 of the [MQTT][] protocol. Make sure that your broker supports and is correctly configured for version 3.1.1. The client is backwards incompatible with brokers running MQTT 3.1.

<table> 
 <tbody> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclient" rel="nofollow">mqtt.Client()</a></td> 
   <td>Creates a MQTT client.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientclose" rel="nofollow">mqtt.client:close()</a></td> 
   <td>Closes connection to the broker.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientconnect" rel="nofollow">mqtt.client:connect()</a></td> 
   <td>Connects to the broker specified by the given host, port, and secure options.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientlwt" rel="nofollow">mqtt.client:lwt()</a></td> 
   <td>Setup Last Will and Testament.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclienton" rel="nofollow">mqtt.client:on()</a></td> 
   <td>Registers a callback function for an event.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientpublish" rel="nofollow">mqtt.client:publish()</a></td> 
   <td>Publishes a message.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientsubscribe" rel="nofollow">mqtt.client:subscribe()</a></td> 
   <td>Subscribes to one or several topics.</td> 
  </tr> 
  <tr> 
   <td><a href="https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientunsubscribe" rel="nofollow">mqtt.client:unsubscribe()</a></td> 
   <td>Unsubscribes from one or several topics.</td> 
  </tr> 
 </tbody> 
</table>

### 3.2.1 所要用到的MQTT相关API ###

（1）[mqtt.Client()][mqtt.Client]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70][]

-- init mqtt client without logins, keepalive timer 120s
    m = mqtt.Client("clientid", 120)
    
    -- init mqtt client with logins, keepalive timer 120sec
    m = mqtt.Client("clientid", 120, "user", "password")
    
    -- setup Last Will and Testament (optional)
    -- Broker will publish a message with qos = 0, retain = 0, data = "offline"
    -- to topic "/lwt" if client don't send keepalive packet
    m:lwt("/lwt", "offline", 0, 0)
    
    m:on("connect", function(client) print ("connected") end)
    m:on("connfail", function(client, reason) print ("connection failed", reason) end)
    m:on("offline", function(client) print ("offline") end)
    
    -- on publish message receive event
    m:on("message", function(client, topic, data)
      print(topic .. ":" )
      if data ~= nil then
        print(data)
      end
    end)
    
    -- on publish overflow receive event
    m:on("overflow", function(client, topic, data)
      print(topic .. " partial overflowed message: " .. data )
    end)
    
    -- for TLS: m:connect("192.168.11.118", secure-port, 1)
    m:connect("192.168.11.118", 1883, false, function(client)
      print("connected")
      -- Calling subscribe/publish only makes sense once the connection
      -- was successfully established. You can do that either here in the
      -- 'connect' callback or you need to otherwise make sure the
      -- connection was established (e.g. tracking connection status or in
      -- m:on("connect", function)).
    
      -- subscribe topic with qos = 0
      client:subscribe("/topic", 0, function(client) print("subscribe success") end)
      -- publish a message with data = hello, QoS = 0, retain = 0
      client:publish("/topic", "hello", 0, 0, function(client) print("sent") end)
    end,
    function(client, reason)
      print("failed reason: " .. reason)
    end)
    
    m:close();
    -- you can call m:connect again

（2）[mqtt.client:connect()][mqtt.client_connect]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 1][]

关于API的使用方法，也可以参考[官网][Link 1]对API的说明。

# 4、连接OneNET #

（1）在OneNET平台创建MQTT的产品；

（2）在MQTT的设备下创建设备；

（3）获取产品的ID，设备ID，设备的鉴权信息；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 2][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 4][]

# 5、编写Lua脚本 #

## 5.1、源代码 ##

cfg = {}
    cfg.ssid = "zwb"--wifi名称
    cfg.pwd = "1234567890"--WiFi密码
    
    wifi.setmode(wifi.STATIONAP)
    wifi.sta.config(cfg)
    wifi.sta.connect()
    
    
    DeviceId = "123456789"--设备ID
    ProductId ="123456789"--产品ID
    AuthoTnfo = "123456"--设备的鉴权信息
    KeepAlive = 20 --心跳间隔，长于此间隔时间则自动与平台断开连接
    host = "183.230.40.39"--OneNET平台MQTT协议的服务器IP
    port = 6002 --服务器对应开放的端口号
    
    
    myClient = mqtt.Client(DeviceId, KeepAlive, ProductId, AuthoTnfo)
    
    timer1 = tmr.create()
    
    function ReConnect()
        if wifi.sta.getip() == nil then
            print("Connect AP,waitting...")
        else
            print("Connected AP,Success!")
            print("IP is:"..wifi.sta.getip())
            print("MAC address:"..wifi.sta.getmac())
            timer1:stop()
    
            myClient:connect(host, port, function(client)
                print("Connected OneNET success!")
            end)
        end
    end
    
    timer1:alarm(1000,tmr.ALARM_AUTO,ReConnect)

## 5.2、代码解析 ##

DeviceId = "123456789"--设备ID  
ProductId ="123456789"--产品ID  
AuthoTnfo = "123456"--设备的鉴权信息  
KeepAlive = 20 --心跳间隔，长于此间隔时间则自动与平台断开连接  
host = "183.230.40.39"--OneNET平台MQTT协议的服务器IP  
port = 6002 --服务器对应开放的端口号

myClient = mqtt.Client(设备ID, 自动断开平台的时间, 产品ID, 设备的鉴权信息)

myClient:connect(平台的IP, 平台开放的端口, 连接成功后的回调函数）

## 5.3、调试 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 5][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p3Yl81NzgyMDkxNjA_size_16_color_FFFFFF_t_70 6][]

[OneNET]: https://blog.csdn.net/zwb_578209160/article/details/113413667
[MQTT_--MQTT]: https://blog.csdn.net/zwb_578209160/article/details/113365191
[MQTT_--MQTT 1]: https://blog.csdn.net/zwb_578209160/article/details/113365620
[wifi]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifigetchannel
[wifi.sta]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifista-module
[wifi.ap]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiap-module
[wifi.ap.dhcp]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifiapdhcp-module
[wifi.eventmon]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifieventmon-module
[wifi.monitor]: https://nodemcu.readthedocs.io/en/release/modules/wifi_monitor/#wifimonitor-module
[NodeMCU_--WiFi]: https://blog.csdn.net/zwb_578209160/article/details/113315330
[Link 1]: https://nodemcu.readthedocs.io/en/release/modules/wifi/#wifisetmode
[MQTT]: https://en.wikipedia.org/wiki/MQTT
[mqtt.Client]: https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclient
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[mqtt.client_connect]: https://nodemcu.readthedocs.io/en/release/modules/mqtt/#mqttclientconnect
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