ESP8266连接阿里云详细代码

以下是ESP8266连接阿里云详细代码：

#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// WiFi信息
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// 阿里云信息
const char* mqttServer = "MQTT_SERVER";
const int mqttPort = 1883;
const char* mqttUser = "MQTT_USER";
const char* mqttPassword = "MQTT_PASSWORD";
const char* mqttClientId = "MQTT_CLIENT_ID";

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);

  while (!client.connected()) {
    Serial.println("Connecting to MQTT server...");
    if (client.connect(mqttClientId, mqttUser, mqttPassword)) {
      Serial.println("Connected to MQTT server");
    } else {
      Serial.print("Failed to connect to MQTT server with state ");
      Serial.println(client.state());
      delay(2000);
    }
  }
  client.subscribe("testTopic");
}

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}

void reconnect() {
  while (!client.connected()) {
    Serial.println("Connecting to MQTT server...");
    if (client.connect(mqttClientId, mqttUser, mqttPassword)) {
      Serial.println("Connected to MQTT server");
      client.subscribe("testTopic");
    } else {
      Serial.print("Failed to connect to MQTT server with state ");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Received [");
  Serial.print(topic);
  Serial.print("]: ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

请将代码中的 `your_SSID`, `your_PASSWORD`, `MQTT_SERVER`, `MQTT_USER`, `MQTT_PASSWORD`, `MQTT_CLIENT_ID` 替换为您自己的信息。此代码使用 `testTopic` 作为订阅主题，您需要自己创建主题并替换此处的主题。