Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <WebServer.h>
#include "RTClib.h"
#include <ArduinoJson.h>
#include <ESP32Servo.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

const char* SSID = "Wokwi-GUEST";
const char* password = "";

RTC_DS1307 rtc;
WebServer server(80);

String correct_password = "147258369";
String entered_password = "";
String checker_state = "Close";

Servo servo;
const int servoPin = 18;
const int Buzzer = 13;

LiquidCrystal_I2C lcd(0x27, 16, 2);

const uint8_t ROWS = 4;
const uint8_t COLS = 3;
char keys[ROWS][COLS] = {
  { '1', '2', '3'},
  { '4', '5', '6'},
  { '7', '8', '9'},
  { '*', '0', '#' }
};
uint8_t colPins[COLS] = { 12, 14, 27 };
uint8_t rowPins[ROWS] = { 26, 25, 33, 32 };
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

float w1 = 0.3, w2 = -0.4, b = 0.05; 
float lr = 0.08;
float loss_values[50];
int loss_index = 0;

const unsigned long AUTO_CLOSE_MS = 10000;
unsigned long openedAt = 0;
const uint8_t MAX_PASS_LEN = 12;

float sigmoid(float x) {
  return 1.0 / (1.0 + exp(-x));
}

void train_model() {
  for (int epoch = 0; epoch < 50; epoch++) {
    float total_loss = 0;
    for (int i = 0; i < 20; i++) {
      float x1 = random(0, 100) / 100.0;
      float x2 = random(0, 100) / 100.0;
      float y = (x1 > 0.8 && x2 > 0.3) ? 0.0 : 1.0;
      float z = w1 * x1 + w2 * x2 + b;
      float pred = sigmoid(z);
      float loss = (pred - y) * (pred - y);
      total_loss += loss;
      float grad = 2 * (pred - y) * pred * (1 - pred);
      w1 -= lr * grad * x1;
      w2 -= lr * grad * x2;
      b -= lr * grad;
    }
    loss_values[loss_index++] = total_loss / 20.0;
    if (loss_index >= 50) loss_index = 0;
  }
}

float predict(float x1, float x2) {
  return sigmoid(w1 * x1 + w2 * x2 + b);
}

String getLossChartJS() {
  String data = "[";
  for (int i = 0; i < 50; i++) {
    data += String(loss_values[i]);
    if (i < 49) data += ",";
  }
  data += "]";
  return data;
}

String getWebPage() {
  String chartData = getLossChartJS();
  String html = R"(
  <html><head>
  <title>AI Safe Monitor</title>
  <script src='https://cdn.jsdelivr.net/npm/chart.js'></script>
  </head><body style='font-family:sans-serif; text-align:center;'>
  <h2>AI Safe Monitor 🔐</h2>
  <canvas id='lossChart' width='300' height='150'></canvas>
  <p id='status'></p>
  <button onclick='trainAgain()'>Retrain AI</button>
  <script>
    const ctx = document.getElementById('lossChart');
    const data = {
      labels: [...Array(50).keys()],
      datasets: [{label:'Loss', data: )" + chartData + R"(, borderColor:'blue', fill:false}]
    };
    new Chart(ctx, {type:'line', data:data});
    async function trainAgain(){
      await fetch('/train');
      alert('Model retrained!');
      location.reload();
    }
    fetch('/state').then(r=>r.text()).then(t=>{document.getElementById('status').innerHTML=t});
  </script>
  </body></html>
  )";
  return html;
}

void handleRoot() {
  server.send(200, "text/html", getWebPage());
}

void handleTrain() {
  train_model();
  server.send(200, "text/plain", "Retrained");
}

void handleState() {
  float sim = 0;
  for (int i = 0; i < entered_password.length() && i < correct_password.length(); i++) {
    if (entered_password[i] == correct_password[i]) sim += 1.0;
  }
  sim /= correct_password.length();
  float delay_factor = (millis() % 100) / 100.0;
  float out = predict(sim, delay_factor);
  String msg = (out > 0.6) ? "⚠️ Suspicious activity detected!" : "✅ Normal operation.";
  server.send(200, "text/plain", msg);
}

void CheckPassword() {
  if (entered_password == correct_password) {
    checker_state = "Open";
    tone(Buzzer, 1500, 150);
    servo.write(90);
    openedAt = millis();
  } else {
    checker_state = "Close";
    tone(Buzzer, 500, 350);
    servo.write(0);
  }
  updateLCD();
}

void setup() {
  Serial.begin(115200);
  WiFi.begin(SSID, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
  Serial.println(WiFi.localIP());

  rtc.begin();
  lcd.init();
  lcd.backlight();
  pinMode(Buzzer, OUTPUT);
  servo.attach(servoPin, 500, 2400);

  server.on("/", handleRoot);
  server.on("/train", handleTrain);
  server.on("/state", handleState);
  server.begin();

  for (int i = 0; i < 50; i++) loss_values[i] = 0.5;

  train_model();
  updateLCD();
}

void updateLCD() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Safe: " + checker_state);
  lcd.setCursor(0, 1);
  String masked = "";
  for (unsigned int i = 0; i < entered_password.length(); i++) masked += '*';
  if (masked.length() > 10) {
    masked = masked.substring(masked.length() - 10);
  }
  lcd.print("Enter: " + masked);
}

void loop() {
  server.handleClient();

  if (checker_state == "Open" && openedAt > 0 && (millis() - openedAt) > AUTO_CLOSE_MS) {
    checker_state = "Close";
    servo.write(0);
    openedAt = 0;
    tone(Buzzer, 1000, 150);
    updateLCD();
  }

  char key = keypad.getKey();
  if (key != NO_KEY) {
    if (key == '#') {
      CheckPassword();
      entered_password = "";
      updateLCD();
    } else if (key == '*') {
      entered_password = "";
      updateLCD();
    } else {
      if (entered_password.length() < MAX_PASS_LEN) {
        entered_password += key;
        updateLCD();
      } else {
        tone(Buzzer, 700, 80);
      }
    }
  }
}