nodemcu.ino

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>

const char* ssid = "myWifiSSID";
const char* password = "myWifiPassWord";

ESP8266WebServer server(80);



void handleRoot() {

  server.send(200, "text/plain", "hello from esp8266!");
 
}

void handleNotFound(){

  String message = "File Not Found\n\n";
  message += "URI: ";
  message += server.uri();
  message += "\nMethod: ";
  message += (server.method() == HTTP_GET)?"GET":"POST";
  message += "\nArguments: ";
  message += server.args();
  message += "\n";
  for (uint8_t i=0; i<server.args(); i++){
    message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
  }
  server.send(404, "text/plain", message);

}

void setup(void){

  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.println("");

  // Wait for connection
  startWIFI();

  if (MDNS.begin("esp8266")) {
    Serial.println("MDNS responder started");
  }

  server.on("/", handleRoot);

  server.on("/inline", [](){
    server.send(200, "text/plain", "this works as well");
  });

  server.onNotFound(handleNotFound);

  server.begin();
  Serial.println("HTTP server started");
}

void loop(void){

  //connect wifi if not connected
  if (WiFi.status() != WL_CONNECTED) {
    delay(1);
    startWIFI();
    return;
  }


  server.handleClient();
}



void startWIFI(void) {

  // Connect to WiFi network
  Serial.println();
  delay(10);
  Serial.println();
  delay(10);
  Serial.print("Connecting to ");
  delay(10);
  Serial.println(ssid);
  delay(10);
  WiFi.begin(ssid, password);

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

  // Start the server
  server.begin();
  Serial.println("Server started");

  // Print the IP address
  Serial.print("ESP8266 IP: ");
  Serial.println(WiFi.localIP());

  // Print the server port
  delay(300);
}