browser control - Wokwi ESP32, STM32, Arduino Simulator

#include <WiFi.h>

// WiFi credentials (Wokwi default)
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Create server on port 80
WiFiServer server(80);

// LED pin (GPIO 2)
#define LED_PIN 2

void setup() {
  Serial.begin(115200);
  Serial.println("Starting...");

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  // Connect to WiFi
  WiFi.begin(ssid, password);
  Serial.print("Connecting");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nConnected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());

  // Start server
  server.begin();
}

void loop() {
  WiFiClient client = server.available();

  if (!client) return;

  Serial.println("New Client Connected");

  // Wait for client request
  while (!client.available()) {
    delay(1);
  }

  // Read request
  String request = client.readStringUntil('\r');
  Serial.println(request);
  client.flush();

  // LED Control
  if (request.indexOf("/ON") != -1) {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("LED ON");
  }
  if (request.indexOf("/OFF") != -1) {
    digitalWrite(LED_PIN, LOW);
    Serial.println("LED OFF");
  }

  // Send FULL HTTP response (VERY IMPORTANT)
  client.println("HTTP/1.1 200 OK");
  client.println("Content-Type: text/html");
  client.println("Connection: close");
  client.println();

  client.println("<!DOCTYPE HTML>");
  client.println("<html>");
  client.println("<head><title>ESP32 Web Server</title></head>");
  client.println("<body style='text-align:center;'>");
  client.println("<h1>ESP32 Web Server</h1>");
  client.println("<p><a href=\"/ON\"><button style='padding:10px;'>LED ON</button></a></p>");
  client.println("<p><a href=\"/OFF\"><button style='padding:10px;'>LED OFF</button></a></p>");
  client.println("</body>");
  client.println("</html>");

  delay(1);
  client.stop(); // VERY IMPORTANT
}