Wokwi - Online ESP32, STM32, Arduino Simulator

#include <Adafruit_NeoPixel.h>
#include <math.h>
#include <WiFi.h>

#define PIN_WS2812B 26  // The ESP32 pin GPIO16 connected to WS2812B
#define NUM_PIXELS 8  // The number of LEDs (pixels) on WS2812B LED strip

String ssid     = "PERSPOLIS";// Replace with your network credentials
String password = "D.a1624s.a";

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

String redString = "0";// Decode HTTP GET value
String greenString = "0";
String blueString = "0";

char r,g,b;

int pos1 = 0;
int pos2 = 0;
int pos3 = 0;
int pos4 = 0;

String header;// Variable to store the HTTP req  uest

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

int area_num = 1, area1 = 8;

Adafruit_NeoPixel ws2812b(NUM_PIXELS, PIN_WS2812B, NEO_GRB + NEO_KHZ800);

void setup() 
{
  Serial.begin(115200);

  pinMode (PIN_WS2812B, OUTPUT);
  ws2812b.begin();  // initialize WS2812B strip object (REQUIRED)

  // 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,
    currentTime = millis();
    previousTime = currentTime;
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    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();
                    
            // 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:,\">");
            client.println("<link rel=\"stylesheet\" href=\"https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css\">");
            client.println("<script src=\"https://cdnjs.cloudflare.com/ajax/libs/jscolor/2.0.4/jscolor.min.js\"></script>");
            client.println("</head><body><div class=\"container\"><div class=\"row\"><h1>ESP Color Picker</h1></div>");
            client.println("<a class=\"btn btn-primary btn-lg\" href=\"#\" id=\"change_color\" role=\"button\">Change Color</a> ");
            client.println("<input class=\"jscolor {onFineChange:'update(this)'}\" id=\"rgb\"></div>");
            client.println("<script>function update(picker) {document.getElementById('rgb').innerHTML = Math.round(picker.rgb[0]) + ', ' +  Math.round(picker.rgb[1]) + ', ' + Math.round(picker.rgb[2]);");
            client.println("document.getElementById(\"change_color\").href=\"?r\" + Math.round(picker.rgb[0]) + \"g\" +  Math.round(picker.rgb[1]) + \"b\" + Math.round(picker.rgb[2]) + \"&\";}</script></body></html>");
            // The HTTP response ends with another blank line
            client.println();
 
            // Request sample: /?r201g32b255&
            // Red = 201 | Green = 32 | Blue = 255
            if(header.indexOf("GET /?r") >= 0) {
              pos1 = header.indexOf('r');
              pos2 = header.indexOf('g');
              pos3 = header.indexOf('b');
              pos4 = header.indexOf('&');
              redString = header.substring(pos1+1, pos2);
              greenString = header.substring(pos2+1, pos3);
              blueString = header.substring(pos3+1, pos4);
              }
            // 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("");
  }

  // turn pixels to green one-by-one with delay between each pixel
  for (int pixel = 0; pixel < area1; pixel++) 
  {   
    int r = redString.length() + 1;
    int g = greenString.length() + 1;
    int b = blueString.length() + 1;    
     // for each pixel
    ws2812b.setPixelColor(pixel, ws2812b.Color(r,g,b));  // it only takes effect if pixels.show() is called
    ws2812b.show();                                          // update to the WS2812B Led Strip
    delay(50);  // 500ms pause between each pixel
  }
}