Problem turning on/off led with arduino webserver (HTML) webpage

Projects Programming
1

Hello,
I am using an arduino uno with an ethernet module. I have wired the ethernet module correctly to the arduino, so that the webpage correctly shows in the browser with the ip address. But when I click on the button to turn the led on, the led does not turn on, even though I have made an if statement with the return result of that button. I have also attatched the led to digital pin 8, and checked that it works

The code is below

I have also attached a screenshot of the html webpage....

#include <SPI.h>
#include <Ethernet.h>



byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xEF, 0xED
};

EthernetServer server (80);
String readString;

int led = 8;



void setup() {
  // put your setup code here, to run once:

  Serial.begin(9600);
  pinMode (led, OUTPUT);
  Ethernet.begin(mac);
  server.begin();
  Serial.print("Server is at ");
  Serial.println(Ethernet.localIP());



}

void loop() {
  // put your main code here, to run repeatedly:



  EthernetClient client = server.available();

  if (client) {
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.print(c);


        if (readString.length() < 100) {
          readString += c;
        }

        if (c = '\n') {
          Serial.print(readString);
          client.println("< HTTP / 1.1 200 OK >");
          client.print("<Connection-Type: text/html>");
          client.println("<Connection: close>");
          client.println("");

          client.println("<!DOCTYPE html>");

          client.println("<html>");
          client.println("<head>");
          client.println("<title>Control the LCD connected to the Arduino</title>");


          client.println("<h1 style=text-align:center>Control the LCD connected to the Arduino</h1>");



          client.println("<head>");
          client.println("<body>");


          client.println("<p></p>");



          client.println("<p>This is a test paragraph</p>");

          client.println("<a href=\"/?button1on\"\"><button> Turn led on </button></a>");

          client.println("<a href=\"/?button2off\"\"><button> Turn led off </button></a>");




          client.println("<body style=background-colour:powderblue>");











          delay(1);
          client.stop();




          if (readString.indexOf ("?button1on") > 0)  {

            digitalWrite(led, HIGH);
          }



          if (readString.indexOf ("?button2off") > 0)  {
            digitalWrite(led, LOW);

          }

          readString = "";




        }

      }

    }
  }
















}

Any help would be really helpful... Thanks.

Screenshot 2021-03-14 at 20.18.41.png
Screenshot 2021-03-14 at 20.18.41.png1917×504 8.47 KB

Screenshot 2021-03-14 at 20.18.41.png
Screenshot 2021-03-14 at 20.18.41.png1917×504 8.47 KB

2 
          client.println("< HTTP / 1.1 200 OK >");
          client.print("<Connection-Type: text/html>");
          client.println("<Connection: close>");

I guess the "<" and ">" characters are your addition, they are wrong and must be removed! Also check the header keys! A correct header is as follows:

          client.println("HTTP/1.0 200 OK");
          client.print("Content-Type: text/html");
          client.println("Connection: close");

The HTML code is correct also. Interesting that your browser is extremely tolerant and displays anyway.
Try this (untested):

          client.println("<!DOCTYPE html>");

          client.println("<html>");
          client.println("<head>");
          client.println("<title>Control the LCD connected to the Arduino</title>");
          client.println("</head>");
          client.println("<body>");
          client.println("<h1 style=\"text-align:center\">Control the LCD connected to the Arduino</h1>");
          client.println("<p></p>");
          client.println("<p>This is a test paragraph</p>");
          client.println("<a href=\"/?button1on\"><button> Turn led on </button></a>");
          client.println("<a href=\"/?button2off\"><button> Turn led off </button></a>");
          client.println("</body></html>");
3

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