ESP8266 LED Control Using WiFi

Introduction

ESP8266 NodeMCU is a powerful WiFi-enabled microcontroller. It allows you to control devices over the internet.

In this tutorial, we will control an LED using a web browser over WiFi.

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Components Required

• ESP8266 NodeMCU
• LED
• 220Ω resistor
• Breadboard
• Jumper wires

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Circuit

• LED positive → D1 pin
• LED negative → 220Ω resistor
• Resistor → GND

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ESP8266 Code

#include <ESP8266WiFi.h>const char* ssid = "YOUR_WIFI";
const char* password = "YOUR_PASSWORD";WiFiServer server(80);int ledPin = D1;void setup() {
  pinMode(ledPin, OUTPUT);
  WiFi.begin(ssid, password);  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }  server.begin();
}void loop() {
  WiFiClient client = server.available();  if (client) {
    String request = client.readStringUntil('\r');    if (request.indexOf("/LED=ON") != -1)
      digitalWrite(ledPin, HIGH);    if (request.indexOf("/LED=OFF") != -1)
      digitalWrite(ledPin, LOW);    client.println("HTTP/1.1 200 OK");
    client.println("Content-Type: text/html");
    client.println("");
    client.println("<a href=\"/LED=ON\">LED ON</a><br>");
    client.println("<a href=\"/LED=OFF\">LED OFF</a>");
  }
}

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How It Works

• ESP8266 connects to WiFi
• A small web server runs on the module
• When you open the IP address in a browser, buttons appear
• Clicking buttons sends commands to control the LED

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Conclusion

This project introduces IoT basics using ESP8266.

You can extend this project to control:

• Relays
• Lights
• Home appliances