iotlight

The best thing about ESP8266 is the web server feature. The chip enable wifi connectivity and can be turned into a small functioning web server. It can connect to the local wifi router and with some dydns configuration and port forwarding basically you can control your ESP8266 from the Internet.

This project will turn LED on and off through web server.

Project item

Nodemcu v1
LED
10k resistor
jumper cable

Connection on breadboard

D6 pin (nodemcu) –> resistor
resistor to Anode (+) Led leg
Cathode Led leg to ground(grn) pin (nodemcu).

Arduino IDE Code

#include <ESP8266WiFi.h>

const char* ssid = "your-wifi-router-id";
const char* password = "your-wifi-password";

int ledPin = 12; // GPIO12 D6
WiFiServer server(80);

void setup() {
  Serial.begin(115200);
  delay(10);

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

  // Connect to WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

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

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

  // Print the IP address
  Serial.print("Use this URL to connect: ");
  Serial.print("http://");
  Serial.print(WiFi.localIP());
  Serial.println("/");

}

void loop() {
  // Check if a client has connected
  WiFiClient client = server.available();
  if (!client) {
    return;
  }

  // Wait until the client sends some data
  Serial.println("new client");
  while (!client.available()) {
    delay(1);
  }

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

  // Match the request
  int value = LOW;
  if (request.indexOf("/LED=ON") != -1) {
    digitalWrite(ledPin, HIGH);
    value = HIGH;
  }
  if (request.indexOf("/LED=OFF") != -1) {
    digitalWrite(ledPin, LOW);
    value = LOW;
  }

  // Set ledPin according to the request
  //digitalWrite(ledPin, value);

  // Return the response
  client.println("HTTP/1.1 200 OK");
  client.println("Content-Type: text/html");
  client.println(""); // do not forget this one
  client.println("<!DOCTYPE HTML>");
  client.println("<html>");

  client.print("Led pin is now: ");

  if (value == HIGH) {
    client.print("On");
  } else {
    client.print("Off");
  }
  client.println("<br><br>");
  client.println("<a href=\"/LED=ON\"><button>ON</button></a>&nbsp;<a href=\"/LED=OFF\"><button>OFF</button></a></p>");
  client.println("</html>");

  delay(1);
  Serial.println("Client disonnected");
  Serial.println("");

}

Verify,Upload and Run.

Download code from github.

Press “control+shift+m” to bring the show serial monitor up. IP address of the web server should show on this monitor. If it is not please check your router information (r-id/password).

Serial Moniter

Web Browser.

Open a web browser and enter the ip addresses provided by the serial monitor Hardware Setup.
Press on or off button. LED should turn on and off based on the button press.

NODEMCU-ARDUINO WEB SERVER CONTROL LED

Control Led through a web server

Project item