Example Code for Arduino - Control LED via WiFi

Hardware Preparation

FireBeetle 2 ESP32-S3 AI Board with OV2640 Camera x 1

Software Preparation

When you use the ESP32 for the first time, you need to know the following steps:

1. Add the ESP32 development board in Arduino IDE (How to add the ESP32 board to Arduino IDE?)

2. Select the development board and serial port

3. Burn the program

Other Preparation Work

• Connect WiFi to “ESP32 S3”, WiFi password: 12345678

• Access the website: http://192.168.4.1/ON to turn on the LED. Enter http://192.168.4.1/OFF to turn off the LED.

• Click here to control the brightness of LED.

Sample Code

/*
**Steps:**
1. Connect WiFit to “ESP32 S3”, WiFi password: 12345678
2. Access the website: http://192.168.4.1/ON to turn on the LED. Enter http://192.168.4.1/OFF to turn off the LED.
3. Click **here** to control the brightness of LED.
*/

#include <WiFi.h>
#include <WiFiClient.h>
#include <WiFiAP.h>

#define myLED 21 //Set pin 21 to the LED pin 
// Set WIFI name and password 
const char *ssid = "ESP32 S3";//WIFI name 
const char *password = "12345678";//password

WiFiServer server(80);//Port 80 is the default web server port 


void setup() {
  pinMode(myLED, OUTPUT);

  Serial.begin(115200);
  Serial.println();
  Serial.println("Configuring access point...");

  //Delete password if you want an open network.
  WiFi.softAP(ssid, password);
  IPAddress myIP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(myIP);
  server.begin();

  Serial.println("Server started");
}

void loop() {
  WiFiClient client = server.available();   // Detect waiting for connection...

  if (client) {                             // Connection detecting 
    Serial.println("New Client.");
    String currentLine = "";                // Create a String variable to store data 
    while (client.connected()) {            // loop when keep connecting
      if (client.available()) {             // Detect is there is data on the connection
        char c = client.read();             // Read the received data 
        //Serial.write(c);                    // Print on serial monitor 
        if (c == '\n') {                    // If an newline character  is read

          //Use newline character to indicate the end
          if (currentLine.length() == 0) {
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println();
             //Connect character with here 
            client.print("Click <a href=\"/ON\">here</a> to turn ON the LED.<br>");
            client.print("Click <a href=\"/OFF\">here</a> to turn OFF the LED.<br>");

            // empty line in a HTTP response
            client.println();
            // Break out of a loop 
            break;
          } else {    // Clear cached data in variable if there is one newline character 
            currentLine = "";
          }
        } else if (c != '\r') {  // If characters except Carriage Return is obtained
          currentLine += c;      // Add the obtained character to end of the variable
        }

        // Check if /ON or /OFF is obtained 
        if (currentLine.endsWith("/ON")) {
          digitalWrite(myLED, HIGH);               //Turn on LED when /ON is obtained 
        }
        if (currentLine.endsWith("/OFF")) {
          digitalWrite(myLED, LOW);                //Turn on LED when /OFF is obtained 
        }
      }
    }
    // disconnect
    client.stop();
    Serial.println("Client Disconnected.");
  }
}

Result

Use the mobile phone to connect to this wifi, access 192.168.4.1 through the browser. As shown in the figure below, the IP address is 192.168.4.1, and the service is enabled.

Access the IP address on a broswer and the fllowing will appear.

Other Supplementary Information

Member function

• WiFiServer server()

  • Description: Set the server port

• softAP(ssid,password)

  • Description: Configure WiFi as AP mode, and set the name and password

  • Parameter:

    • ssid: wifi name in AP mode

    • password: wifi password in ap mode

• server.available()

  • Description: Check whether there is connection on service port(whether WIFI is connected)

• client.connected()

  • Description: Check connection status

  • Return value: true/false

• client.available()

  • Description: Detect whether there is data input from the WIFI it is connected to

• client.read()

  • Description: Read the data received by WiFi

• currentLine.endsWith()

  • Description: if it ends with the given suffix in the bracket

• client.stop()

  • Description: Disconnect