写一个ESP8266获取天气的函数

以下是一个基于ESP8266的获取天气的函数示例：

#include <ESP8266WiFi.h>
#include <WiFiClientSecure.h>
#include <ArduinoJson.h>

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

const char* host = "api.openweathermap.org";
const int httpsPort = 443;
const char* fingerprint = "your_SSL_FINGERPRINT";

void setup() {
  Serial.begin(115200);
  delay(10);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    WiFiClientSecure client;
    client.setFingerprint(fingerprint);
    if (!client.connect(host, httpsPort)) {
      Serial.println("connection failed");
      return;
    }
    String url = "/data/2.5/weather?q=London,uk&appid=your_APPID";
    client.print(String("GET ") + url + " HTTP/1.1\r\n" +
                 "Host: " + host + "\r\n" +
                 "Connection: close\r\n\r\n");
    while (client.connected()) {
      String line = client.readStringUntil('\n');
      if (line == "\r") {
        break;
      }
    }
    String response = "";
    while (client.available()) {
      response += client.readString();
    }
    const size_t bufferSize = JSON_OBJECT_SIZE(3) + JSON_OBJECT_SIZE(4) + JSON_OBJECT_SIZE(5) + JSON_OBJECT_SIZE(6) + JSON_OBJECT_SIZE(8) + JSON_OBJECT_SIZE(11) + JSON_OBJECT_SIZE(12) + JSON_OBJECT_SIZE(13) + JSON_OBJECT_SIZE(14) + JSON_OBJECT_SIZE(15) + 400;
    DynamicJsonBuffer jsonBuffer(bufferSize);
    JsonObject& root = jsonBuffer.parseObject(response);
    if (!root.success()) {
      Serial.println("parseObject() failed");
      return;
    }
    const char* cityName = root["name"];
    float temperature = root["main"]["temp"];
    const char* description = root["weather"][0]["description"];
    Serial.print("City: ");
    Serial.println(cityName);
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");
    Serial.print("Description: ");
    Serial.println(description);
  }
  delay(60000); // 1 minute
}

这个函数使用ESP8266连接到OpenWeatherMap API，并获取伦敦的天气信息。你需要将 `your_SSID`，`your_PASSWORD`，`your_SSL_FINGERPRINT` 和 `your_APPID` 替换为你自己的 WiFi 和 OpenWeatherMap API 的访问信息。

该函数使用 `WiFiClientSecure` 连接到 API，以确保安全连接。然后，它构建一个 URL，并发送一个 GET 请求。一旦收到响应，它使用 ArduinoJson 库解析 JSON 数据，并提取城市名称、温度和天气描述。最后，它打印这些信息到串口监视器。

该函数每分钟执行一次，以获取最新的天气信息。你可以根据自己的需要更改这个频率。