https://randomnerdtutorials.com/esp8266-web-server-with-arduino-ide/

ESP8266 Web Server with Arduino IDE

In this project you’ll create a standalone web server with an ESP8266 that can toggle two LEDs using Arduino IDE. This ESP8266 Web Server is mobile responsive and it can be accessed with any device that as a browser in your local network.

For a more in-depth tutorial on how to create a web server, and explanation of the code, read this post ESP8266 Web Server Step-by-step

If you want to learn more about the ESP8266 module, first read my Getting Started Guide for the ESP8266 WiFi Module.

If you like the ESP and you want to do more projects you can read my eBook Home Automation Using ESP8266.

Let’s get started!

First, watch the video tutorial

Uploading the ESP8266 code

Having the ESP8266 add-on for the Arduino IDE installed (How to Install the ESP8266 Board in Arduino IDE), go to Tools and select “Generic ESP8266 Module”.

Copy the sketch below to your Arduino IDE. Replace the SSID and password with your own network credentials.

const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

After modifying the sketch upload it to your ESP8266 (If you can’t upload code to your ESP8266, read this troubleshooting guide).

/*********
  Rui Santos
  Complete project details at https://randomnerdtutorials.com  
*********/

// Load Wi-Fi library
#include <ESP8266WiFi.h>

// Replace with your network credentials
const char* ssid     = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

// Set web server port number to 80
WiFiServer server(80);

// Variable to store the HTTP request
String header;

// Auxiliar variables to store the current output state
String output5State = "off";
String output4State = "off";

// Assign output variables to GPIO pins
const int output5 = 5;
const int output4 = 4;

// Current time
unsigned long currentTime = millis();
// Previous time
unsigned long previousTime = 0; 
// Define timeout time in milliseconds (example: 2000ms = 2s)
const long timeoutTime = 2000;

void setup() {
  Serial.begin(115200);
  // Initialize the output variables as outputs
  pinMode(output5, OUTPUT);
  pinMode(output4, OUTPUT);
  // Set outputs to LOW
  digitalWrite(output5, LOW);
  digitalWrite(output4, LOW);

  // Connect to Wi-Fi network with SSID and password
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  // Print local IP address and start web server
  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  server.begin();
}

void loop(){
  WiFiClient client = server.available();   // Listen for incoming clients

  if (client) {                             // If a new client connects,
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    currentTime = millis();
    previousTime = currentTime;
    while (client.connected() && currentTime - previousTime <= timeoutTime) { // loop while the client's connected
      currentTime = millis();         
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == '\n') {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
            
            // turns the GPIOs on and off
            if (header.indexOf("GET /5/on") >= 0) {
              Serial.println("GPIO 5 on");
              output5State = "on";
              digitalWrite(output5, HIGH);
            } else if (header.indexOf("GET /5/off") >= 0) {
              Serial.println("GPIO 5 off");
              output5State = "off";
              digitalWrite(output5, LOW);
            } else if (header.indexOf("GET /4/on") >= 0) {
              Serial.println("GPIO 4 on");
              output4State = "on";
              digitalWrite(output4, HIGH);
            } else if (header.indexOf("GET /4/off") >= 0) {
              Serial.println("GPIO 4 off");
              output4State = "off";
              digitalWrite(output4, LOW);
            }
            
            // Display the HTML web page
            client.println("<!DOCTYPE html><html>");
            client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
            client.println("<link rel=\"icon\" href=\"data:,\">");
            // CSS to style the on/off buttons 
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
            client.println(".button { background-color: #195B6A; border: none; color: white; padding: 16px 40px;");
            client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
            client.println(".button2 {background-color: #77878A;}</style></head>");
            
            // Web Page Heading
            client.println("<body><h1>ESP8266 Web Server</h1>");
            
            // Display current state, and ON/OFF buttons for GPIO 5  
            client.println("<p>GPIO 5 - State " + output5State + "</p>");
            // If the output5State is off, it displays the ON button       
            if (output5State=="off") {
              client.println("<p><a href=\"/5/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/5/off\"><button class=\"button button2\">OFF</button></a></p>");
            } 
               
            // Display current state, and ON/OFF buttons for GPIO 4  
            client.println("<p>GPIO 4 - State " + output4State + "</p>");
            // If the output4State is off, it displays the ON button       
            if (output4State=="off") {
              client.println("<p><a href=\"/4/on\"><button class=\"button\">ON</button></a></p>");
            } else {
              client.println("<p><a href=\"/4/off\"><button class=\"button button2\">OFF</button></a></p>");
            }
            client.println("</body></html>");
            
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
  }
}

View raw code

Upload code to ESP8266-01

If you’re using an ESP8266-01, you need an FTDI programmer to upload the code. Wire the ESP8266 to the FTDI programmer as shown in the following schematic diagram.

ESP8266 IP Address

Open the Arduino serial monitor at a baud rate of 115200.

• If you’re using ESP8266-01, connect GPIO 0 to VCC and reset your board.
• If you’re using ESP8266-12E, just press the RESET button.

After a few seconds, the ESP8266 IP address should appear.

Parts Required

Here’s the hardware that you need to complete this project:

• ESP8266 – read Best ESP8266 Wi-Fi Development Boards
• 2x LED
• 2x 330 Ohm resistor (220 Ohm or other values also work)
• Breadboard
• Jumper wires

If you’re using an ESP8266-01, you need an FTDI programmer to upload code.

You can use the preceding links or go directly to MakerAdvisor.com/tools to find all the parts for your projects at the best price!

Final Circuit

Follow the next schematic diagram to build the circuit you’ll control. One LED connected to GPIO 4(D2) and another connected to GPIO 5(D1).

If you’re using the ESP8266-01, use the following schematic diagram as a reference, but you need change the GPIOs assignment in the code (to GPIO 2 and GPIO 0).

Demonstration

For the final demonstration open any browser from a device that is connected to the same router that your ESP8266 is. Then, type the ESP8266 IP address and click Enter!

Now , press the buttons in your web server to control the ESP8266 GPIOs.

Wrapping Up

For an in-depth explanation on how the web server code works, please refer to this tutorial: ESP8266 Web Server Step-by-step