目标：开发esp32通过onenet平台远程控制LED、继电器等其它设备，并利用onenet可视化功能开发出一个简单的控制页面。

原以为能够快速完成，没想到接入mqtt协议、数据流上传、可视化按键都不同程度遇到了问题，还好经过一番查找和修改，终于初步完成了前两个功能，可视化按键是因为我需要远程控制继电器，刚开始时，一直无数据流可选择。没想到需要通过数据流来进行，所以需要在代码创建一个数据3laig流，虽然我在onenet平台也创建数据流，但在可视化界面一直不显示。明天在尝试一下新的方法。

发现有许多网友其实也不太清楚怎么连接onenet,我也是站在前人的基础上摸索了好久。

这几天一直在上班，没有太多来深入，一直利用下班时间来完成，续更中。。。。。。

 

 

1、参考链接：ESP32+MQTT+OneNet上报数据点+平台命令控制LED - Arduino专区 - OneNET设备云论坛 (10086.cn)

2、参考代码： 

#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
//#include <ArduinoJson.h>
#include "DHT.h"#define DHTPIN 5      // Digital pin connected to the DHT sensor
#define DHTTYPE DHT11 // DHT 11
#define BUILTIN_LED 21// Update these with values suitable for your network.const char *ssid = "Oppo-Xu";        //wifi名
const char *password = "123456ABC";      //wifi密码
const char *mqtt_server ="183.230.40.96"; //onenet 的 IP地址const char *clientid = "smartlight";//OneNet注册设备的“设备名称”
const char *userid = "ze3xOCB42t";//OneNet 注册的MQTT产品的“产品ID”
const char *mqtt_password ="version=2018-10-31&res=products%2Fze3xOCB42t%2Fdevices%2Fsmartlight&et=1923199463&method=md5&sign=uG4snxEt7s%2Bqi55uPtCtxA%3D%3D";//OneNet 注册的MQTT产品的“产品ID”char outTopic[] = "$sys/ze3xOCB42t/smartlight/dp/post/json";//数据上传的Topic,格式为“$sys/userid/clientid/dp/post/json”
char inTopic[] = "$sys/ze3xOCB42t/smartlight/dp/post/json/+";//数据返回的Topic，格式为“$sys/userid/clientid/dp/post/json/+”
char cmdTopic[] = "$sys/ze3xOCB42t/smartlight/cmd/#";//接收平台命令的TOPIC，格式为“$sys/userid/clientid/cmd/#”
int switch0 = 0;//开关状态DHT dht(DHTPIN, DHTTYPE);
WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
//数据上报格式模板，按网上例程的不成功，只能按下列格式，有Temperatrue、Humidity、switch0三个数据点
char dataTemplete[] = "{\"id\":1,\"dp\":{\"Temperatrue\":[{\"v\":%5.1f}],\"Humidity\":[{\"v\":%d}],\"switch0\":[{\"v\":%d}]}}";
char msgJson[100];//上传的数据
int h = 10;void setup_wifi()
{delay(10);// We start by connecting to a WiFi networkSerial.println();Serial.print("Connecting to ");Serial.println(ssid);WiFi.begin(ssid, password);while (WiFi.status() != WL_CONNECTED){delay(500);Serial.print(".");}randomSeed(micros());Serial.println("");Serial.println("WiFi connected");Serial.println("IP address: ");Serial.println(WiFi.localIP());//  digitalWrite(BUILTIN_LED, HIGH);
}//收到订阅Topic信息的回调处理
void callback(char *topic, byte *payload, unsigned int length)
{Serial.print("Message arrived [");Serial.print(topic);Serial.print("] ");for (int i = 0; i < length; i++){Serial.print((char)payload[i]);}Serial.println();// 平台发来命令“1”时开灯if ((char)payload[0] == '1'){switch0 = 1;//digitalWrite(BUILTIN_LED, HIGH);}else{switch0 = 0;//digitalWrite(BUILTIN_LED, LOW);}digitalWrite(BUILTIN_LED, switch0);
}void reconnect()
{//循环连接while (!client.connected()){Serial.print("Attempting MQTT connection...");if (client.connect(clientid, userid, mqtt_password)){ Serial.println("connected");//订阅inTop的消息,上报数据后平台自动发来的//client.unsubscribe (inTopic);        client.subscribe(cmdTopic); //订阅平台发来命令消息}else{Serial.print("failed, rc=");Serial.print(client.state());Serial.println(" try again in 5 seconds");// Wait 5 seconds before retryingdelay(5000);}}
}void setup()
{pinMode(BUILTIN_LED, OUTPUT); // Initialize the BUILTIN_LED pin as an output, where do it esp32 get gpio21 as ledSerial.begin(115200);setup_wifi();client.setServer(mqtt_server, 1883); //按OneNet开发文档设置端口为1883client.setCallback(callback);//dht.begin();
}void loop()
{if (!client.connected()){reconnect();}client.loop();long now = millis();if (now - lastMsg > 2000){float t = 15.5;lastMsg = now;sprintf(msgJson, dataTemplete, t, h, switch0);//按模板格式化上传数据到msgJsonSerial.print("Publish message: ");Serial.println(msgJson);client.publish(outTopic, msgJson);//上传}h=h+2;    
}