ESP8266 Motion Sensor Security System

/*********************************************************************
 * ESP8266 Motion Sensor Security System
 * 
 * Detects motion and sends Telegram notifications
 * Hardware: NodeMCU, HC-SR501 PIR, Buzzer, LED
 *********************************************************************/

#include 
#include 
#include 

// ============== WIFI ==============
const char* wifi_ssid = "YOUR_WIFI";
const char* wifi_password = "YOUR_PASSWORD";

// ============== TELEGRAM ==============
#define BOT_TOKEN "YOUR_BOT_TOKEN"
#define CHAT_ID "YOUR_CHAT_ID"

WiFiClientSecure client;
UniversalTelegramBot bot(BOT_TOKEN, client);

// ============== PINS ==============
#define MOTION_SENSOR D1
#define BUZZER_PIN D2
#define LED_PIN D3

// ============== CONFIG ==============
unsigned long lastMotionTime = 0;
const unsigned long ALERT_COOLDOWN = 30000;  // 30 seconds
bool motionDetected = false;

void setup() {
  Serial.begin(115200);
  
  pinMode(MOTION_SENSOR, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  
  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LED_PIN, LOW);
  
  connectToWiFi();
  client.setCACert(TELEGRAM_CERTIFICATE_ROOT);
  
  Serial.println(F("Security system active!"));
}

void loop() {
  if (digitalRead(MOTION_SENSOR) == HIGH) {
    if (millis() - lastMotionTime > ALERT_COOLDOWN) {
      triggerAlarm();
      lastMotionTime = millis();
    }
  }
  delay(100);
}

void triggerAlarm() {
  Serial.println(F("MOTION DETECTED!"));
  
  // Flash LED
  for (int i = 0; i < 10; i++) {
    digitalWrite(LED_PIN, HIGH);
    delay(100);
    digitalWrite(LED_PIN, LOW);
    delay(100);
  }
  
  // Sound buzzer
  digitalWrite(BUZZER_PIN, HIGH);
  delay(500);
  digitalWrite(BUZZER_PIN, LOW);
  
  // Send Telegram
  String msg = "🚨 Motion detected at " + String(millis()/1000) + " seconds ago!";
  bot.sendMessage(CHAT_ID, msg, "");
}

void connectToWiFi() {
  WiFi.begin(wifi_ssid, wifi_password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(F("."));
  }
  Serial.println(F(" Connected!"));
}