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初出茅庐的小李博客之使用立创开发板(ESP32)连接到EMQX Platform【MQTT TLS/SSL 端口连接】

news 来源：原创 2024/9/28 14:15:17

介绍

手上有一块立创开发板，本着不吃灰的原则把它用起来，今天就来用它来连接上自己部署的MQTT服务器进行数据通信。

硬件：立创开发板
开发环境：Arduino IDE Win11
MQTT 平台：EMQX Platform

在这里插入图片描述

立创开发板介绍：

初出茅庐的小李博客之立创开发板初体验【Arduino IDE开发环境】：
地址：https://blog.csdn.net/weixin_43176183/article/details/139101412?spm=1001.2014.3001.5501

MQTT.fx客户端接入EMQX Platform

初出茅庐的小李博客之MQTT.fx客户端接入EMQX Platform
地址：https://blog.csdn.net/weixin_43176183/article/details/139190727?spm=1001.2014.3001.5501

参考文档：
https://docs.emqx.com/zh/cloud/latest/connect_to_deployments/esp32.html

过程记录：

安装MQTT依赖库

在 Arduino IDE 中完成以下安装。
先安装 ESP32 开发板。
点击工具 -> 开发板 -> 开发板管理。搜索 ESP32，点击安装我已经安装过。
安装 PubSub client 库。
点击项目 -> 加载库 -> 管理库…。搜索 PubSubClient，安装 PubSubClient by Nick O’Leary。
通过 TCP 端口连接
在这里插入图片描述

写代码

引入对应的库


#include "WiFi.h"
#include <PubSubClient.h>
#include <WiFiClientSecure.h>

定义用户自定义参数


// WiFi Credentials
const char *ssid     = "AQST";             // Replace with your WiFi name
const char *password = "12345678";         // Replace with your WiFi password// MQTT Broker Settings
const char *mqtt_broker   = "xxxxxx.ala.cn-hangzhou.emqxsl.cn";//这里定义自己的连接地址
const char *mqtt_topic    = "emqx/esp32";
const char *mqtt_username = "AQ";
const char *mqtt_password = "123456";
const int   mqtt_port     = 8883;

编写连接代码【准确的来说叫改写】

/连接Wifi热点函数
void ConnectToWiFi(void) 
{WiFi.begin(ssid, password);Serial.print("Connecting to WiFi");while (WiFi.status() != WL_CONNECTED){delay(500);Serial.print(".");}Serial.println("\nConnected to WiFi");
}
//连接MQTT代理函数
void ConnectToMQTT(void) 
{while (!mqtt_client.connected()){String client_id = "esp32-client-" + String(WiFi.macAddress());Serial.printf("Connecting to MQTT Broker as %s...\n", client_id.c_str());if(mqtt_client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {Serial.println("Connected to MQTT broker");mqtt_client.subscribe(mqtt_topic);mqtt_client.publish(mqtt_topic, "Hi EMQX I'm ESP32 by Arduino IED ^^");  // Publish message upon connection}else {Serial.print("Failed to connect to MQTT broker, rc=");Serial.print(mqtt_client.state());Serial.println(" Retrying in 5 seconds.");delay(5000);}}
}
//MQTT 回调函数
void MqttCallback(char *topic, byte *payload, unsigned int length)
{Serial.print("Message received on topic: ");Serial.println(topic);Serial.print("Message: ");for (unsigned int i = 0; i < length; i++) {Serial.print((char) payload[i]);//打印有效载荷的信息}Serial.println("\n-----------------------");
}

函数调用


void setup(void)
{Serial.begin(115200);                         //设置串口参数ConnectToWiFi();                              //连接Wifi热点// Set Root CA certificateespClient.setCACert(ca_cert);                 //设置CA证书mqtt_client.setServer(mqtt_broker, mqtt_port);//指定代理 指定端口mqtt_client.setKeepAlive(60);                 //保活时间mqtt_client.setCallback(MqttCallback);        //回调函数ConnectToMQTT();                              //连接MQTT 代理}void loop(void) 
{if (!mqtt_client.connected()) {ConnectToMQTT();}mqtt_client.loop();
}

特别提示：这里的地址要写自己的地址 CA证书也要用自己的证书否则连不上

官方原话：
添加服务端证书。如果您在使用公共 MQTT Broker、Serverless 部署或基础版部署的 TLS/SSL 端口连接，在此下载 CA 证书。 如您使用专业版 / BYOC 部署的 TLS/SSL 端口连接，请使用自己的服务端证书。

开启MQTT服务器
编译烧录代码

在这里插入图片描述

用MQTT.fx连接到MQTT服务器跟ESP32开发板进行通信

发布消息：

在这里插入图片描述

ESP32收到订阅消息

在这里插入图片描述
这里可以看到开发板收到了消息但是客户端提示收到的消息不是标准json

改进一下发送的数据格式

{"mag": "This is Json Data"
}

在这里插入图片描述

总结：

利用Arduino IED 进行MQTT通信确实很方便，很容易就能实现两个设备的交互、但是使用库的缺点也很明显有很多api不太懂它的意思，还需要进一步研究。

完整代码


#include "WiFi.h"
#include <PubSubClient.h>
#include <WiFiClientSecure.h>// WiFi Credentials
const char *ssid     = "AQST";             // Replace with your WiFi name
const char *password = "12345678";         // Replace with your WiFi password// MQTT Broker Settings
const char *mqtt_broker   = "xxxxxxx.ala.cn-hangzhou.emqxsl.cn";//这里要改成自己的地址！！！！
const char *mqtt_topic    = "emqx/esp32";
const char *mqtt_username = "AQ";
const char *mqtt_password = "123456";
const int   mqtt_port     = 8883;WiFiClientSecure espClient;
PubSubClient mqtt_client(espClient);void ConnectToWiFi(void);//函数声明
void ConnectToMQTT(void);//函数声明
void MqttCallback(char *mqtt_topic, byte *payload, unsigned int length);//函数声明const char *ca_cert = R"EOF(
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
)EOF";void setup(void)
{Serial.begin(115200);                         //设置串口参数ConnectToWiFi();                              //连接Wifi热点// Set Root CA certificateespClient.setCACert(ca_cert);                 //设置CA证书mqtt_client.setServer(mqtt_broker, mqtt_port);//指定代理 指定端口mqtt_client.setKeepAlive(60);                 //保活时间mqtt_client.setCallback(MqttCallback);        //回调函数ConnectToMQTT();                              //连接MQTT 代理}//连接Wifi热点函数
void ConnectToWiFi(void) 
{WiFi.begin(ssid, password);Serial.print("Connecting to WiFi");while (WiFi.status() != WL_CONNECTED){delay(500);Serial.print(".");}Serial.println("\nConnected to WiFi");
}
//连接MQTT代理函数
void ConnectToMQTT(void) 
{while (!mqtt_client.connected()){String client_id = "esp32-client-" + String(WiFi.macAddress());Serial.printf("Connecting to MQTT Broker as %s...\n", client_id.c_str());if(mqtt_client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {Serial.println("Connected to MQTT broker");mqtt_client.subscribe(mqtt_topic);mqtt_client.publish(mqtt_topic, "Hi EMQX I'm ESP32 by Arduino IED ^^");  // Publish message upon connection}else {Serial.print("Failed to connect to MQTT broker, rc=");Serial.print(mqtt_client.state());Serial.println(" Retrying in 5 seconds.");delay(5000);}}
}
//MQTT 回调函数
void MqttCallback(char *topic, byte *payload, unsigned int length)
{Serial.print("Message received on topic: ");Serial.println(topic);Serial.print("Message: ");for (unsigned int i = 0; i < length; i++) {Serial.print((char) payload[i]);//打印有效载荷的信息}Serial.println("\n-----------------------");
}void loop(void) 
{if (!mqtt_client.connected()) {ConnectToMQTT();}mqtt_client.loop();
}// WiFiClient espClient;
// PubSubClient mqtt_client(espClient);// void setup(void) 
// {
//   Serial.begin(115200);
//   ConnectToWiFi(); //连接指定热点
//   //mqtt_client.setServer(mqtt_broker, mqtt_port);
//   espClient.setCACert(ca_cert);
//   mqtt_client.setKeepAlive(60);
//   mqtt_client.setCallback(MqttCallback); // Corrected callback function name
//   ConnectToMQTT();
// }// void loop(void) 
// {
//   if (!mqtt_client.connected()) 
//   {
//     ConnectToMQTT();
//   }
//   mqtt_client.loop();
// }//用户自定义函数
// void ConnectToWiFi(void) 
// {
//     WiFi.begin(ssid, password);
//     Serial.print("Connecting to WiFi");
//     while (WiFi.status() != WL_CONNECTED) 
//     {
//         delay(500);
//         Serial.print(".");
//     }
//     Serial.println("\nConnected to WiFi");
// }
// //用户自定义函数
// void ConnectToMQTT(void) 
// {
//   while (!mqtt_client.connected()) 
//   {
//     String client_id = "esp32-client-" + String(WiFi.macAddress());//     Serial.printf("Connecting to MQTT Broker as %s.....\n", client_id.c_str());//     if (mqtt_client.connect(client_id.c_str(), mqtt_username, mqtt_password))
//     {
//       Serial.println("Connected to MQTT broker");
//       mqtt_client.subscribe(mqtt_topic);
//       mqtt_client.publish(mqtt_topic, "Hi EMQX I'm ESP32 ^^"); // Publish message upon successful connection
//     }
//     else 
//     {
//       Serial.print("Failed, rc=");
//       Serial.print(mqtt_client.state());
//       Serial.println(" try again in 5 seconds");
//       delay(5000);
//     }
//   }
// }//用户自定义回调函数
// void MqttCallback(char *mqtt_topic, byte *payload, unsigned int length)
// {
//   Serial.print("Message received on mqtt_topic: ");
//   Serial.println(mqtt_topic);
//   Serial.print("Message: ");
//   for (unsigned int i = 0; i < length; i++) 
//   {
//     Serial.print((char) payload[i]);
//   }
//   Serial.println("\n-----------------------");
// }