写一个用arudino开发的温湿度传感器传送数据到MOTT服务器的代码

以下是一个基于Arduino开发的温湿度传感器上传数据到MQTT服务器的示例代码：

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <WiFi.h>
#include <PubSubClient.h>

// Wi-Fi参数
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// MQTT参数
const char* mqtt_server = "your_MQTT_server_address";
const char* mqtt_username = "your_MQTT_username";
const char* mqtt_password = "your_MQTT_password";
const char* mqtt_client_id = "your_MQTT_client_id";
const char* mqtt_topic = "your_MQTT_topic";

// DHT传感器参数
#define DHTPIN 4          // DHT传感器连接的引脚
#define DHTTYPE DHT11     // DHT11型号
DHT dht(DHTPIN, DHTTYPE);

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);
  delay(10);
  
  // 连接Wi-Fi
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // 连接MQTT服务器
  client.setServer(mqtt_server, 1883);
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect(mqtt_client_id, mqtt_username, mqtt_password)) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying in 5 seconds");
      delay(5000);
    }
  }

  // 初始化DHT传感器
  dht.begin();
}

void loop() {
  delay(2000);

  // 读取温湿度数据
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  // 检查是否读取成功
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // 将温湿度数据转换为JSON格式
  String payload = "{\"temperature\":";
  payload += t;
  payload += ",\"humidity\":";
  payload += h;
  payload += "}";

  // 将数据发布到MQTT服务器
  Serial.print("Publishing to ");
  Serial.print(mqtt_topic);
  Serial.print(" -> ");
  Serial.println(payload);
  client.publish(mqtt_topic, payload.c_str());
}

在上面的代码中，我们使用了DHT库来读取温湿度传感器的数据，并使用WiFi和PubSubClient库连接到MQTT服务器并将数据发布到指定的主题上。需要将代码中的Wi-Fi和MQTT参数替换为自己的参数才能正常工作。