esp8266连接onenet代码

以下是 ESP8266 连接 OneNET 的基本代码示例：

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

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

// OneNET平台信息
const char* server = "your_server_name";
const char* apiKey = "your_apiKey";
const char* topic = "your_topic";

WiFiClient wifiClient;
PubSubClient client(wifiClient);

void setup() {
  Serial.begin(115200);
  delay(10);
  
  // 连接WiFi
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("WiFi connected, IP address: ");
  Serial.println(WiFi.localIP());

  // 连接OneNET
  client.setServer(server, 1883);
  client.setCallback(callback);
  while (!client.connected()) {
    Serial.println("Connecting to OneNET MQTT...");
    if (client.connect("ESP8266Client", apiKey, "")) {
      Serial.println("Connected to OneNET MQTT");
      client.subscribe(topic);
    } else {
      Serial.print("Failed with state ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

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

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

void reconnect() {
  while (!client.connected()) {
    Serial.println("Reconnecting to OneNET MQTT...");
    if (client.connect("ESP8266Client", apiKey, "")) {
      Serial.println("Connected to OneNET MQTT");
      client.subscribe(topic);
    } else {
      Serial.print("Failed with state ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

需要替换的信息包括：

- `your_SSID` 和 `your_PASSWORD`：WiFi的SSID和密码；
- `your_server_name`：OneNET平台的MQTT服务器地址；
- `your_apiKey`：OneNET平台的API KEY；
- `your_topic`：订阅的Topic名称。

代码中的 `callback` 函数是收到消息时的回调函数，可以自行修改。

注意，需要在代码中导入两个库：`ESP8266WiFi.h` 和 `PubSubClient.h`。如果你使用的是 Arduino IDE，可以在菜单栏中选择“工具” -> “管理库”，搜索并安装这两个库。

另外，需要在 OneNET 平台上创建应用和设备，并获取 API KEY 和 Topic 名称。可以参考 OneNET 的官方文档进行操作。