Toggle LED from NodeMCU using WIFI.

NodeMCU_LED_ON_OFF.ino

/*
open browser and hit 
192.168.1.167/?1 to ON
192.168.1.167/?0 to OFF

*/


#include <ESP8266WiFi.h>

const char* ssid = "Your_WiFi_SSID";
const char* password = "Your_WiFi_Password";
const int ledPin = 2;
WiFiServer server(1337);

void printWiFiStatus();

void setup(void) {
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  IPAddress ip(192, 168, 1, 167);
  IPAddress gateway(192, 168, 1, 1);
  IPAddress subnet(255, 255, 255, 0);
  WiFi.config(ip, gateway, subnet);

  // Configure GPIO2 as OUTPUT.
  pinMode(ledPin, OUTPUT);

  // Start TCP server.
  server.begin();
}

void loop(void) {
  // Check if module is still connected to WiFi.
  if (WiFi.status() != WL_CONNECTED)
  {
    while (WiFi.status() != WL_CONNECTED)
    {
      delay(500);
    }
    // Print the new IP to Serial.
    printWiFiStatus();
  }

  WiFiClient client = server.available();
  if (client)
  {
    Serial.println("Client connected.");
    while (client.connected())
    {
      if (client.available())
      {
        char command = client.read();
        if (command == '0')
        {
          digitalWrite(ledPin, HIGH); Serial.println("LED is now on."); client.stop();
        }
        else if (command == '1')
        {
          digitalWrite(ledPin, LOW); Serial.println("LED is now off."); client.stop();
        } 
      }
    }
    Serial.println("Client disconnected.");
    //client.stop();
  }
}

void printWiFiStatus() {
  Serial.println("");
  Serial.print("Connected to ");  Serial.println(ssid);
  Serial.print("IP address: ");  Serial.println(WiFi.localIP());
}