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

// Definisi pin sesuai wiring Anda
#define DHTPIN 8
#define BUZZER_PIN 13
#define LED_MERAH 31 
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Variabel status untuk mencegah buzzer berdering saat suhu di rentang hibrida (47-49 C)
bool statusBahaya = false;

void setup() {
  Serial.begin(9600);
  dht.begin();
  lcd.begin(16, 2);
  
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_MERAH, OUTPUT);

  // Paksa kondisi awal mati total
  noTone(BUZZER_PIN);
  digitalWrite(BUZZER_PIN, LOW);
  digitalWrite(LED_MERAH, LOW);
}

void loop() {
  float suhu = dht.readTemperature();

  // Jika pembacaan sensor gagal, lewati siklus loop
  if (isnan(suhu)) {
    Serial.println("Gagal membaca sensor DHT!");
    return;
  }

  // Tampilkan Suhu di Baris Pertama LCD
  lcd.setCursor(0, 0);
  lcd.print("Suhu: ");
  lcd.print(suhu, 1);
  lcd.print((char)223); // Simbol derajat °
  lcd.print("C   ");

  // ==========================================
  // LOGIKA HISTERESIS (Sesuai Struktur)
  // ==========================================
  if (suhu >= 50) {
    statusBahaya = true;   // Aktifkan mode bahaya saat suhu >= 50
  } 
  else if (suhu < 47) {
    statusBahaya = false;  // Baru nonaktifkan mode bahaya jika suhu turun di bawah 47
  }

  // ==========================================
  // EKSEKUSI AOUTPUT (If-Else Bersih)
  // ==========================================
  if (statusBahaya) {
    tone(BUZZER_PIN, 1000);        // Buzzer bunyi
    digitalWrite(LED_MERAH, HIGH);  // LED Merah nyala
    
    lcd.setCursor(0, 1);
    lcd.print("Status: BAHAYA! ");
  } 
  else {
    noTone(BUZZER_PIN);             // Matikan frekuensi tone
    digitalWrite(BUZZER_PIN, LOW);  // Paksa pin 13 ke GND (0V) agar tidak ada arus sisa
    digitalWrite(LED_MERAH, LOW);   // LED Merah mati
    
    lcd.setCursor(0, 1);
    lcd.print("Status: AMAN    ");
  }

  delay(500); 
}

More projects by s160425118

• Sistem Keamanan Rumah Arduino — Arduino Uno