ESP8266是一種廣泛使用的Wi-Fi模塊，可以輕松連接到互聯網，實現物聯網的應用，其中包括傳輸JSON文件。下面基于ESP8266為主要的開發板來介紹如何發送JSON文件。

#include#includeconst char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
const char* server_hostname = "your_SERVER_NAME";
const int server_port = 80;
const char* url = "/your_URL";
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
Serial.print("\n\nConnecting to ");
Serial.print(ssid);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
}
void loop() {
WiFiClient client;
if (client.connect(server_hostname, server_port)) {
int jsonLength = 12;
char json[jsonLength];
strcpy(json, "{\"test\":1}");
String request = "POST ";
request += url;
request += " HTTP/1.1\r\n";
request += "Host: ";
request += server_hostname;
request += "\r\n";
request += "Content-Type: application/json\r\n";
request += "Content-Length: ";
request += String(jsonLength);
request += "\r\n\r\n";
request += json;
Serial.println("Sending JSON: ");
Serial.println(request);
client.print(request);
Serial.println("Response from server:");
while (client.available()) {
char c = client.read();
Serial.write(c);
}
client.stop();
}
delay(5000);
}

以上是發送JSON文件的ESP8266代碼，主要是首先將WiFi模塊連接到網絡，然后通過WiFiClient對象建立到服務器的連接。接下來構造HTTP POST請求，將json變量作為請求體發送，通過client.print()方法發送請求并跟蹤來自服務器的響應。

現在，ESP8266將JSON文件成功發送到服務器，開發者可以嘗試從服務器端獲取JSON并進行處理。