ESP8266-aRest.ino

// Import required libraries
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <WiFiClient.h>
#include <Servo.h>
#include <ESP8266mDNS.h>

//Static IP address configuration
IPAddress staticIP(192, 168, 1, 176); //ESP static ip
IPAddress gateway(192, 168, 1, 1);   //IP Address of your WiFi Router (Gateway)
IPAddress subnet(255, 255, 255, 0);  //Subnet mask

//On board LED Connected to GPIO2
#define LED 2  

// WiFi parameters
const char* ssid = "MyWifiName";
const char* password = "MyWifiPassword";

////Declare a global object variable from the ESP8266WebServer class.
ESP8266WebServer server(80); //Server on port 80

Servo servo;

void handleLEDon() {
 Serial.println("LED on page");
 digitalWrite(LED,LOW); //LED is connected in reverse
 delay(20); // If the issue is caused by the watchdog timer, adding small delays fix the issue
 ESP.wdtFeed();
 servo.write(1);
 server.send(200, "text/html", "LED is ON"); //Send ADC value only to client ajax request
}

void handleLEDoff() {
 Serial.println("LED off page");
 digitalWrite(LED,HIGH); //LED off
 delay(20); // If the issue is caused by the watchdog timer, adding small delays fix the issue
 ESP.wdtFeed();
 servo.write(120);
 server.send(200, "text/html", "LED is OFF"); //Send ADC value only to client ajax request
}

void setup(void) {
  pinMode(LED, OUTPUT);     // Initialize the LED_BUILTIN pin as an output
  // Start Serial
  Serial.begin(115200);
  WiFi.disconnect();  //Prevent connecting to wifi based on previous configurati
  ESP.eraseConfig();
  WiFi.config(staticIP, subnet, gateway);
  WiFi.mode(WIFI_STA); //WiFi mode station (connect to wifi router only
  WiFi.setSleepMode(WIFI_NONE_SLEEP);
  WiFi.begin(ssid, password);

  // Connect to WiFi

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) { // blink to indicate the device is trying to connect to WIFI
    digitalWrite(LED,LOW);
    delay(100);
    digitalWrite(LED,HIGH);
    delay(400);
    Serial.print(".");
  }

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

  // Start the server
  server.on("/ledOn", handleLEDon); //as Per  <a href="ledOn">, Subroutine to be called
  server.on("/ledOff", handleLEDoff);
  server.begin();                  //Start server
  Serial.println("HTTP server started");
  
  // Print the IP address
  Serial.println(WiFi.localIP());
  digitalWrite(LED,LOW);
  servo.attach(14); //GPIO15 = D5
  servo.write(1);
}

void loop() {
  server.handleClient();          //Handle client requests
  MDNS.update();
}