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ESP32 - Web Server Multiple Pages
In this tutorial, we'll find out how to turn an ESP32 into a web server that can handle multiple pages at the same time, such as index.html, temperature.html, led.html, error_404.html, and error_405.html...
By following this tutorial, you will be able to turn your ESP32 into a web server with some cool features:
- Multiple web pages are active simultaneously.
- The HTML content (including HTML, CSS, and Javascript) for each page is kept separately in its own file on the Arduino IDE.
- The HTML content can be dynamically updated with real-time values from sensors, making the web pages dynamic and responsive.
- The web server allows to control something connected to ESP32 via web.
- The web server handles HTTP error codes such as 404 Not Found and 405 Method Not Allowed
It might sound complicated, but don't worry! This tutorial provides step-by-step guidance, and the code is designed to be beginner-friendly, ensuring that you can easily comprehend and create your own ESP32 web server.
Hardware Used In This Tutorial
| 1 | × | ESP-WROOM-32 Dev Module | |
| 1 | × | USB Cable Type-C | |
| 1 | × | (Recommended) Screw Terminal Expansion Board for ESP32 |
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: some of these links are affiliate links. We may earn a commission on your purchase at no extra cost to you. We appreciate it.
Introduction to ESP32 and Web Server
If you're not familiar with ESP32 and Web Server (including pinout, how it works, and programming), you can learn about them through the following tutorials:
ESP32 Code - Multiple-page Web server
Below is the complete ESP32 code that creates a web server with multiple pages. To keep it simple, the HTML content for each page is very simple and embedded directly in the ESP32 code. In the another part, we will learn how to separate the HTML contents for each page into separate files, making the code more organized and manageable.
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#define LED_PIN 18 // ESP32 pin GPIO18 connected to LED
const char *ssid = "YOUR_WIFI_SSID"; // CHANGE IT
const char *password = "YOUR_WIFI_PASSWORD"; // CHANGE IT
AsyncWebServer server(80);
int LED_state = LOW;
float getTemperature() {
// YOUR SENSOR IMPLEMENTATION HERE
// simulate the temperature value
float temp_x100 = random(0, 10000); // a ramdom value from 0 to 10000
return temp_x100 / 100; // return the simulated temperature value from 0 to 100 in float
}
void setup() {
Serial.begin(9600);
pinMode(LED_PIN, OUTPUT);
// Connect to Wi-Fi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
// Print the ESP32's IP address
Serial.print("ESP32 Web Server's IP address: ");
Serial.println(WiFi.localIP());
// Serve the specified HTML pages
server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.println("Web Server: home page");
request->send(200, "text/html", "This is the ESP32 home page");
});
server.on("/temperature.html", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.println("Web Server: temperature page");
float temperature = getTemperature();
request->send(200, "text/html", "Temperature: " + String(temperature));
});
server.on("/led.html", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.print("Web Server: LED page");
// Check for the 'state' parameter in the query string
if (request->hasArg("state")) {
String state = request->arg("state");
if (state == "on") {
LED_state = HIGH;
} else if (state == "off") {
LED_state = LOW;
}
// control LED here
digitalWrite(LED_PIN, LED_state);
Serial.print(" => turning LED to ");
Serial.print(state);
}
Serial.println();
request->send(200, "text/html", "LED state: " + String(LED_state));
});
// 404 and 405 error handler
server.onNotFound([](AsyncWebServerRequest *request) {
if (request->method() == HTTP_GET) {
// Handle 404 Not Found error
Serial.println("Web Server: Not Found");
request->send(404, "text/html", "Not Found");
} else {
// Handle 405 Method Not Allowed error
Serial.println("Web Server: Method Not Allowed");
request->send(405, "text/html", "Method Not Allowed");
}
});
server.begin();
Serial.println("ESP32 Web server started");
}
void loop() {
// Your code can go here or be empty; the server is handled asynchronously
}
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Do the wiring as above image.
- Connect the ESP32 board to your PC via a micro USB cable
- Open Arduino IDE on your PC.
- Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
- Open the Library Manager by clicking on the Library Manager icon on the left navigation bar of Arduino IDE.
- Search “ESPAsyncWebServer”, then find the ESPAsyncWebServer created by lacamera.
- Click Install button to install ESPAsyncWebServer library.
- You will be asked to install the dependency. Click Install All button.
- Copy the above code and open with Arduino IDE
- Change the wifi information (SSID and password) in the code to yours
- Click Upload button on Arduino IDE to upload code to ESP32
- Open the Serial Monitor
- Check out the result on Serial Monitor.
COM6
Connecting to WiFi...
Connected to WiFi
ESP32 Web Server's IP address: 192.168.0.2
ESP32 Web server started
Autoscroll
Clear output
9600 baud
Newline
- You will see an IP address on the Serial Monitor, for example: 192.168.0.2
- Type the following list one-by-one on the address bar of a web browser on your smartphone or PC.
192.168.0.2
192.168.0.2/index.html
192.168.0.2/led.html
192.168.0.2/temperature.html
192.168.0.2/blabla.html
- Please note that you need to change the 192.168.0.2 to the IP address you got on Serial Monitor.
- You will see the following pages: home page, led page, temperature page, and Not Found page
- You can also check the output on Serial Monitor
COM6
Connecting to WiFi...
Connected to WiFi
ESP32 Web Server's IP address: 192.168.0.2
ESP32 Web server started
Web Server: home page
Web Server: LED page
Web Server: LED page => turning LED to on
Web Server: LED page => turning LED to off
Web Server: temperature page
Web Server: Not Found
Autoscroll
Clear output
9600 baud
Newline
The previous code has very simple HTML content for each page. But if we want to make a fancy interface with lots of HTML, the code can get big and messy. To make it simpler, we will learn how to separate the HTML from the ESP32 code. This lets us keep the HTML in separate files, making it easier to manage and work with.
ESP32 Code - Complete multiple-page Web server
- Open the Arduino IDE.
- Create a new sketch and give it a name, for example, ESP32WebServer.ino.
- Copy the provided code and paste it into that file.
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#include "index.h"
#include "temperature.h"
#include "led.h"
#include "error_404.h"
#include "error_405.h"
#define LED_PIN 18 // ESP32 pin GPIO18 connected to LED
const char *ssid = "YOUR_WIFI_SSID"; // CHANGE IT
const char *password = "YOUR_WIFI_PASSWORD"; // CHANGE IT
AsyncWebServer server(80);
int LED_state = LOW;
float getTemperature() {
// YOUR SENSOR IMPLEMENTATION HERE
// simulate the temperature value
float temp_x100 = random(0, 10000); // a ramdom value from 0 to 10000
return temp_x100 / 100; // return the simulated temperature value from 0 to 100 in float
}
void setup() {
Serial.begin(9600);
pinMode(LED_PIN, OUTPUT);
// Connect to Wi-Fi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("Connected to WiFi");
// Print the ESP32's IP address
Serial.print("ESP32 Web Server's IP address: ");
Serial.println(WiFi.localIP());
// Serve the specified HTML pages
server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.println("Web Server: home page");
String html = HTML_CONTENT_HOME; // Use the HTML content from the index.h file
request->send(200, "text/html", html);
});
server.on("/temperature.html", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.println("Web Server: temperature page");
String html = HTML_CONTENT_TEMPERATURE; // Use the HTML content from the temperature.h file
float temperature = getTemperature();
html.replace("%TEMPERATURE_VALUE%", String(temperature)); // update the temperature value
request->send(200, "text/html", html);
});
server.on("/led.html", HTTP_GET, [](AsyncWebServerRequest *request) {
Serial.print("Web Server: LED page");
// Check for the 'state' parameter in the query string
if (request->hasArg("state")) {
String state = request->arg("state");
if (state == "on") {
LED_state = HIGH;
} else if (state == "off") {
LED_state = LOW;
}
// control LED here
digitalWrite(LED_PIN, LED_state);
Serial.print(" => turning LED to ");
Serial.print(state);
}
Serial.println();
String html = HTML_CONTENT_LED; // Use the HTML content from the led.h file
html.replace("%LED_STATE%", LED_state ? "ON" : "OFF"); // update the LED state
request->send(200, "text/html", html);
});
// 404 and 405 error handler
server.onNotFound([](AsyncWebServerRequest *request) {
if (request->method() == HTTP_GET) {
// Handle 404 Not Found error
Serial.println("Web Server: Not Found");
String html = HTML_CONTENT_404; // Use the HTML content from the error_404.h file
request->send(404, "text/html", html);
} else {
// Handle 405 Method Not Allowed error
Serial.println("Web Server: Method Not Allowed");
String html = HTML_CONTENT_405; // Use the HTML content from the error_405.h file
request->send(405, "text/html", html);
}
});
server.begin();
Serial.println("ESP32 Web server started");
}
void loop() {
// Your code can go here or be empty; the server is handled asynchronously
}
- Change the WiFi information (SSID and password) in the code to yours
- Create the index.h file On Arduino IDE by:
- Either click on the button just below the serial monitor icon and choose New Tab, or use Ctrl+Shift+N keys.
- Give file's name index.h and click OK button
- Copy the below code and paste it to the index.h file.
- Similarly, Create the led.h file On Arduino IDE with the following content.
- Similarly, Create the temperature.h file On Arduino IDE with the following content.
- Similarly, Create the error_404.h file On Arduino IDE with the following content.
- Similarly, Create the error_405.h file On Arduino IDE with the following content.
- Now you have multiple files on Arduino IDE like below:
- Click Upload button on Arduino IDE to upload code to ESP32
- Access the web pages of ESP32 board via web browser one by one as before. You will see all web page as below:
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
const char *HTML_CONTENT_HOME = R"=====(
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" href="data:,">
<title>Home Page</title>
</head>
<body>
<h1>Welcome to the Home Page</h1>
<ul>
<li><a href="/led.html">LED Page</a></li>
<li><a href="/temperature.html">Temperature Page</a></li>
</ul>
</body>
</html>
)=====";
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
const char *HTML_CONTENT_LED = R"=====(
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" href="data:,">
<title>LED Page</title>
</head>
<body>
<h1>LED Page</h1>
<p>LED State: <span style="color: red;">%LED_STATE%</span></p>
<a href='/led.html?state=on'>Turn ON</a>
<br><br>
<a href='/led.html?state=off'>Turn OFF</a>
</body>
</html>
)=====";
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
const char *HTML_CONTENT_TEMPERATURE = R"=====(
<!DOCTYPE html>
<html>
<head>
<title>ESP32 - Web Temperature</title>
<meta name="viewport" content="width=device-width, initial-scale=0.7, maximum-scale=0.7">
<meta charset="utf-8">
<link rel="icon" href="https://diyables.io/images/page/diyables.svg">
<style>
body { font-family: "Georgia"; text-align: center; font-size: width/2pt;}
h1 { font-weight: bold; font-size: width/2pt;}
h2 { font-weight: bold; font-size: width/2pt;}
button { font-weight: bold; font-size: width/2pt;}
</style>
<script>
var cvs_width = 200, cvs_height = 450;
function init() {
var canvas = document.getElementById("cvs");
canvas.width = cvs_width;
canvas.height = cvs_height + 50;
var ctx = canvas.getContext("2d");
ctx.translate(cvs_width/2, cvs_height - 80);
update_view(%TEMPERATURE_VALUE%);
}
function update_view(temp) {
var canvas = document.getElementById("cvs");
var ctx = canvas.getContext("2d");
var radius = 70;
var offset = 5;
var width = 45;
var height = 330;
ctx.clearRect(-cvs_width/2, -350, cvs_width, cvs_height);
ctx.strokeStyle="blue";
ctx.fillStyle="blue";
//5-step Degree
var x = -width/2;
ctx.lineWidth=2;
for (var i = 0; i <= 100; i+=5) {
var y = -(height - radius)*i/100 - radius - 5;
ctx.beginPath();
ctx.lineTo(x, y);
ctx.lineTo(x - 20, y);
ctx.stroke();
}
//20-step Degree
ctx.lineWidth=5;
for (var i = 0; i <= 100; i+=20) {
var y = -(height - radius)*i/100 - radius - 5;
ctx.beginPath();
ctx.lineTo(x, y);
ctx.lineTo(x - 25, y);
ctx.stroke();
ctx.font="20px Georgia";
ctx.textBaseline="middle";
ctx.textAlign="right";
ctx.fillText(i.toString(), x - 35, y);
}
// shape
ctx.lineWidth=16;
ctx.beginPath();
ctx.arc(0, 0, radius, 0, 2 * Math.PI);
ctx.stroke();
ctx.beginPath();
ctx.rect(-width/2, -height, width, height);
ctx.stroke();
ctx.beginPath();
ctx.arc(0, -height, width/2, 0, 2 * Math.PI);
ctx.stroke();
ctx.fillStyle="#e6e6ff";
ctx.beginPath();
ctx.arc(0, 0, radius, 0, 2 * Math.PI);
ctx.fill();
ctx.beginPath();
ctx.rect(-width/2, -height, width, height);
ctx.fill();
ctx.beginPath();
ctx.arc(0, -height, width/2, 0, 2 * Math.PI);
ctx.fill();
ctx.fillStyle="#ff1a1a";
ctx.beginPath();
ctx.arc(0, 0, radius - offset, 0, 2 * Math.PI);
ctx.fill();
temp = Math.round(temp * 100) / 100;
var y = (height - radius)*temp/100.0 + radius + 5;
ctx.beginPath();
ctx.rect(-width/2 + offset, -y, width - 2*offset, y);
ctx.fill();
ctx.fillStyle="red";
ctx.font="bold 34px Georgia";
ctx.textBaseline="middle";
ctx.textAlign="center";
ctx.fillText(temp.toString() + "°C", 0, 100);
}
window.onload = init;
</script>
</head>
<body>
<h1>ESP32 - Web Temperature</h1>
<canvas id="cvs"></canvas>
</body>
</html>
)=====";
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
const char *HTML_CONTENT_404 = R"=====(
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" href="data:,">
<title>404 - Page Not Found</title>
<style>
h1 {color: #ff4040;}
</style>
</head>
<body>
<h1>404</h1>
<p>Oops! The page you are looking for could not be found on Esp32 Web Server.</p>
<p>Please check the URL or go back to the <a href="/">homepage</a>.</p>
<p>Or check <a href="https://esp32io.com/tutorials/esp32-web-server-multiple-pages"> Esp32 Web Server</a> tutorial.</p>
</body>
</html>
)=====";
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-web-server-multiple-pages
*/
const char *HTML_CONTENT_405 = R"=====(
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="icon" href="data:,">
<title>405 - Method Not Allowed</title>
<style>
h1 {color: #ff4040;}
</style>
</head>
<body>
<h1>405 - Method Not Allowed</h1>
<p>Oops! The requested method is not allowed for this resource.</p>
<p>Please check your request or go back to the <a href="/">homepage</a>.</p>
<p>Or check <a href="https://esp32io.com/tutorials/esp32-web-server-multiple-pages"> Esp32 Web Server</a> tutorial.</p>
</body>
</html>
)=====";
