Wokwi - Online ESP32, STM32, Arduino Simulator

#include <WiFi.h>
#include <WebServer.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

const char* ssid = "ESP32-AP";
const char* password = "12345678";

const int pirPin = 2;       // PIR sensor
const int ledPin = 18;      // LED alarm
const int buzzerPin = 19;   // Buzzer alarm
const int buttonPin = 35;   // Reset button

bool alarmOn = false;

WebServer server(80);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void handleRoot() {
  String html = "<html><head><meta charset=\"utf-8\"><title>Security System</title></head><body>";
  html += "<h1>Alarm Status</h1>";
  html += "<p>Status: <b style='color:";
  html += alarmOn ? "red'>⚠️ ALARM TRIGGERED ⚠️" : "green'>✅ Normal";
  html += "</b></p>";
  html += "<form action='/reset' method='get'>";
  html += "<button style='padding:10px;font-size:16px;'>Reset Alarm</button>";
  html += "</form></body></html>";

  server.send(200, "text/html; charset=utf-8", html);
}

void handleReset() {
  resetAlarm();
  server.sendHeader("Location", "/");
  server.send(303);
}

void resetAlarm() {
  alarmOn = false;
  digitalWrite(ledPin, LOW);
  digitalWrite(buzzerPin, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Status: Normal");
}

void checkPIR() {
  int pirState = digitalRead(pirPin);
  if (pirState == HIGH && !alarmOn) {
    alarmOn = true;
    Serial.println("Motion detected! Alarm triggered!");
    digitalWrite(ledPin, HIGH);
    digitalWrite(buzzerPin, HIGH);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(" ALARM TRIGGERED");
  }
}

void checkButton() {
  if (digitalRead(buttonPin) == LOW && alarmOn) {
    Serial.println("🔘 Reset button pressed.");
    resetAlarm();
    delay(500);  // debounce
  }
}

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

  pinMode(pirPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP); // internal pull-up

  // LCD init
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0, 0);
  lcd.print("System Starting...");

  delay(2000);

  resetAlarm();

  WiFi.softAP(ssid, password);
  Serial.println("✅ ESP32 AP started");
  Serial.print("👉 IP address: ");
  Serial.println(WiFi.softAPIP());

  server.on("/", HTTP_GET, handleRoot);
  server.on("/reset", HTTP_GET, handleReset);
  server.begin();
  Serial.println("✅ HTTP server started");
}

void loop() {
  server.handleClient();
  checkPIR();
  checkButton();
}