A basic ESP32 Web server example

In this example we will create a basic web server with an ESP32, we will then serve a we page with an on and off button which will switch an LED on and off

Parts Required

1x ESP32 Dev Module (Lolin32)
1x LED
1x Breadboard
1x 470 Ohm Resistor
Jumper wires

 

Layout

This was the best ESP32 fritzing part I could find

 

esp32 and led
esp32 and led

 

Code

Adding support for ESP32 boards Рshowed how to add support to the Arduino IDE

 

#include <WiFi.h>
 
// Replace with your network credentials
const char* ssid     = "iainhendry";
const char* password = "iain061271";
 
WiFiServer server(80);
 
const int led =  15;      // the number of the LED pin
 
// Client variables 
char linebuf[80];
int charcount=0;
 
void setup() 
{
  // initialize the LED as an output:
  pinMode(led, OUTPUT);
  //Initialize serial and wait for port to open:
  Serial.begin(115200);
  while(!Serial) {
  }
 
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
 
  WiFi.begin(ssid, password);
 
  // attempt to connect to Wifi network:
  while(WiFi.status() != WL_CONNECTED) 
  {
    // Connect to WPA/WPA2 network.
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP()); 
  server.begin();
}
 
void loop() 
{
  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) 
  {
    Serial.println("New client");
    memset(linebuf,0,sizeof(linebuf));
    charcount=0;
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) 
    {
      if (client.available()) 
      {
        char c = client.read();
        Serial.write(c);
        //read char by char HTTP request
        linebuf[charcount]=c;
        if (charcount<sizeof(linebuf)-1) charcount++;
 
        if (c == '\n' && currentLineIsBlank) 
        {
          // send a standard http response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          client.println();
          client.println("<!DOCTYPE HTML><html><head>");
          client.println("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1\"></head>");
          client.println("<h1>ESP32 - Web Server example</h1>");
          client.println("<p>LED <a href=\"on\"><button>ON</button></a>&nbsp;<a href=\"off\"><button>OFF</button></a></p>");
          client.println("</html>");
          break;
        }
        if (c == '\n') 
        {
          // you're starting a new line
          currentLineIsBlank = true;
          if (strstr(linebuf,"GET /on") > 0)
          {
            Serial.println("LED ON");
            digitalWrite(led, HIGH);
          }
          else if (strstr(linebuf,"GET /off") > 0)
          {
            Serial.println("LED OFF");
            digitalWrite(led, LOW);
          }
 
          // you're starting a new line
          currentLineIsBlank = true;
          memset(linebuf,0,sizeof(linebuf));
          charcount=0;
        } 
        else if (c != '\r') 
        {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(1);
 
    // close the connection:
    client.stop();
    Serial.println("client disconnected");
  }
}

 

Testing

Open the serial monitor to get the assigned IP address, in your favourite web browser navigate to this IP address

This is my example

esp32 webpage
esp32 webpage

 

Now press the on and off button and check if the LED flashes

 

Links

 
You can pick up a module for about $8, this makes it a more costly option than an ESP8266 but the bluetooth and extra digital and analog ports make it well worth it in my book

Official DOIT ESP32 Development Board WiFi+Bluetooth Ultra-Low Power Consumption Dual Core ESP-32

LEAVE A REPLY

Please enter your comment!
Please enter your name here

*