Smart Home Security Alarm — Arduino Mega simulation

Sistem keamanan rumah dan alarm multi-bahaya menggunakan Arduino Mega dengan sensor PIR, DHT11, Keypad, LCD, dan Buzzer.

An interactive Arduino Mega circuit simulation you can run free in your browser on Velxio, by s160425118.

Components

• Resistor 220 x3
• Led x2
• Buzzer
• Grove Dht11
• Junction
• Lcd1602
• Membrane Keypad
• Pir Motion Sensor

Sketch code

#include <LiquidCrystal.h>
#include <Keypad.h>
#include <DHT.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2); 
const int pirPin = 7;
const int buzzerPin = 13;
const int ledPIRPin = 30;
const int ledTempPin = 31;

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},{'4','5','6','B'},{'7','8','9','C'},{'*','0','#','D'}
};
byte rowPins[ROWS] = {22, 23, 24, 25};
byte colPins[COLS] = {26, 27, 28, 29};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

DHT dht(8, DHT11);

bool systemArmed = true;
bool alarmAktif = true; 

// Timer untuk pembacaan DHT agar tidak merusak timing loop
unsigned long lastDHTRead = 0;
float temp = 0.0;

void setup() {
  Serial.begin(9600);
  pinMode(pirPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPIRPin, OUTPUT);
  pinMode(ledTempPin, OUTPUT);
  
  // Pastikan awal-awal buzzer mati total
  noTone(buzzerPin);
  digitalWrite(buzzerPin, LOW);
  
  dht.begin();
  lcd.begin(16, 2);
}

void loop() {
  char key = keypad.getKey();

  if (key == '*') {
    alarmAktif = false;
    noTone(buzzerPin);
    digitalWrite(buzzerPin, LOW); // Paksa mati
    Serial.println(">>> MUTE AKTIF");
  } else if (key == '#') {
    systemArmed = !systemArmed;
    alarmAktif = true; // Reset alarm saat ganti status ARM
    noTone(buzzerPin);
    digitalWrite(buzzerPin, LOW);
  }

  if (systemArmed) {
    // 1. Baca Sensor PIR
    bool intruder = (digitalRead(pirPin) == HIGH);

    // 2. Baca DHT11 setiap 2 detik sekali (agar pembacaan stabil)
    if (millis() - lastDHTRead >= 2000 || lastDHTRead == 0) {
      lastDHTRead = millis();
      float readT = dht.readTemperature();
      if (!isnan(readT)) {
        temp = readT;
      }
    }
    
    bool hot = (temp > 40.0);

    // Nyalakan LED Indikator
    digitalWrite(ledPIRPin, intruder ? HIGH : LOW);
    digitalWrite(ledTempPin, hot ? HIGH : LOW);

    // ===================================================
    // KONTROL BUZZER (FIX: DIAM JIKA TIDAK ADA BAHAYA)
    // ===================================================
    if ((intruder || hot) && alarmAktif) {
      tone(buzzerPin, 1000); // Bunyi HANYA saat ada bahaya DAN tidak di-mute
    } else {
      // Hentikan frekuensi tone dan matikan pin secara fisik
      noTone(buzzerPin);
      digitalWrite(buzzerPin, LOW); 
    }

    // TAMPILAN LCD
    lcd.setCursor(0, 0);
    if (!alarmAktif) {
      lcd.print("ALARM MUTED     ");
    } else if (intruder && hot) {
      lcd.print("!!! INTR + FIRE !");
    } else if (intruder) {
      lcd.print("!!! BAHAYA !");
    } else if (hot) {
      lcd.print("!!! FIRE !");
    } else {
      lcd.print("SYSTEM ARMED    ");
    }
    
    lcd.setCursor(0, 1);
    lcd.print("Temp: "); 
    lcd.print(temp, 1); 
    lcd.print("C   ");

  } else {
    // Kondisi DISARM: Buzzer dan LED DIJAMIN MATI
    noTone(buzzerPin);
    digitalWrite(buzzerPin, LOW);
    digitalWrite(ledPIRPin, LOW);
    digitalWrite(ledTempPin, LOW);
    
    lcd.setCursor(0, 0);
    l

More projects by s160425118

• Smart Home Security Alarm (copy) (copy) — Arduino Mega
• Smart Home Security Alarm (copy) — Arduino Mega
• Sistem Keamanan Rumah Arduino — Arduino Uno