在 ESP32 上发送 POST 请求

要在ESP32上发送POST请求，您需要使用ESP32的WiFi功能连接到互联网，并使用HTTP客户端库发送POST请求。下面是一个示例代码，可以在ESP32上使用Arduino IDE进行编写和上传：

#include <WiFi.h>
#include <HTTPClient.h>

// Replace with your network credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// Your Domain name with URL path or IP address with path
const char* serverName = "http://yourdomain.com/api/post_data";

void setup() {
  //Initialize serial and wait for port to open:
  Serial.begin(115200);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  // We start by connecting to a WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }

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

void loop() {
  // Use WiFiClient class to create TCP connections
  WiFiClient client;

  HTTPClient http;

  Serial.print("[HTTP] begin...\n");
  // configure server and url
  http.begin(client, serverName);

  Serial.print("[HTTP] POST...\n");
  // start connection and send HTTP header
  int httpResponseCode = http.POST("Hello World");

  // httpCode will be negative on error
  if (httpResponseCode > 0) {
    // HTTP header has been send and Server response header has been handled
    Serial.printf("[HTTP] POST... code: %d\n", httpResponseCode);

    // file found at server
    if (httpResponseCode == HTTP_CODE_OK) {
      String payload = http.getString();
      Serial.println(payload);
    }
  } else {
    Serial.printf("[HTTP] POST... failed, error: %s\n", http.errorToString(httpResponseCode).c_str());
  }

  http.end();
  delay(10000);
}

将上面的示例代码中的“your_SSID”和“your_PASSWORD”替换为您的WiFi网络凭据，并将“serverName”替换为您要发送POST请求的URL或IP地址。然后，您可以上传并运行代码，ESP32将连接到WiFi网络并发送POST请求。