Gambaran Umum

Sistem ini mengotomatisasi perangkat elektronik di ruang kelas seperti lampu, proyektor, dan AC berdasarkan:

• Keberadaan orang (sensor gerak PIR)
• Tingkat cahaya ruangan (sensor LDR)
• Jadwal pelajaran (opsional via integrasi kalender)
• Input manual melalui antarmuka web atau Telegram

Kebutuhan Perangkat Keras

• ESP32 Development Board (dengan Wi-Fi & Bluetooth)
• Sensor PIR HC-SR501 (deteksi gerak/orang)
• Sensor LDR (Light Dependent Resistor)
• Modul Relay 4-channel (untuk mengontrol lampu, proyektor, AC)
• Lampu LED, proyektor, atau perangkat listrik 220V (dikontrol via relay)
• Resistor 10kΩ (untuk LDR), resistor 220Ω (opsional)
• Breadboard dan kabel jumper

Kebutuhan Perangkat Lunak

• Arduino IDE atau PlatformIO
• Library ESP32: WiFi.h, WebServer.h, ArduinoJson.h
• Akun Telegram Bot (untuk notifikasi dan kontrol jarak jauh)
• Jaringan Wi-Fi di sekolah

Langkah Instalasi

1. Pasang library di Arduino IDE:

   Tools → Manage Libraries → Cari "ArduinoJson" dan "ESP32"

2. Sambungkan komponen:
   • PIR OUT → GPIO 13
   • LDR → GPIO 34 (analog input)
   • Relay IN1 → GPIO 25 (lampu)
   • Relay IN2 → GPIO 26 (proyektor)
   • Relay IN3 → GPIO 27 (AC atau kipas)
3. Konfigurasi Wi-Fi & Telegram: Ganti SSID, password, token bot, dan chat ID di kode.
4. Upload kode ke ESP32: Pilih board “ESP32 Dev Module”, lalu upload.
5. Akses antarmuka web: Buka alamat IP ESP32 di browser (misal: 192.168.1.100).

Kode Program Lengkap (smart_classroom.ino)

#include 
#include 
#include 

// Konfigurasi Wi-Fi
const char* ssid = "NAMA_SSID";
const char* password = "PASSWORD_SSID";

// Telegram
const char* botToken = "ISI_DENGAN_TOKEN_BOT_ANDA";
const char* chatId = "ISI_DENGAN_CHAT_ID_ANDA";

// Pin GPIO
#define PIR_PIN 13
#define LDR_PIN 34
#define RELAY_LAMP 25
#define RELAY_PROJ 26
#define RELAY_FAN 27

WebServer server(80);

bool lampState = false;
bool projState = false;
bool fanState = false;

void sendTelegram(String message) {
  String url = "https://api.telegram.org/bot" + String(botToken) + "/sendMessage?chat_id=" + String(chatId) + "&text=" + message;
  HTTPClient http;
  http.begin(url);
  http.GET();
  http.end();
}

void handleRoot() {
  String html = "
Smart Classroom Controller
";
  html += "
Lampu: " + String(lampState ? "ON" : "OFF") + "
";
  html += "Toggle Lampu

";
  html += "Toggle Proyektor";
  server.send(200, "text/html", html);
}

void toggleLamp() {
  lampState = !lampState;
  digitalWrite(RELAY_LAMP, lampState ? LOW : HIGH); // Relay aktif LOW
  server.send(200, "text/plain", "OK");
  sendTelegram("💡 Lampu " + String(lampState ? "dinyalakan" : "dimatikan"));
}

void toggleProj() {
  projState = !projState;
  digitalWrite(RELAY_PROJ, projState ? LOW : HIGH);
  server.send(200, "text/plain", "OK");
  sendTelegram("📽️ Proyektor " + String(projState ? "dinyalakan" : "dimatikan"));
}

void setup() {
  Serial.begin(115200);
  pinMode(PIR_PIN, INPUT);
  pinMode(LDR_PIN, INPUT);
  pinMode(RELAY_LAMP, OUTPUT);
  pinMode(RELAY_PROJ, OUTPUT);
  pinMode(RELAY_FAN, OUTPUT);
  digitalWrite(RELAY_LAMP, HIGH);
  digitalWrite(RELAY_PROJ, HIGH);
  digitalWrite(RELAY_FAN, HIGH);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected to WiFi");
  Serial.println(WiFi.localIP());

  server.on("/", handleRoot);
  server.on("/lamp/toggle", toggleLamp);
  server.on("/proj/toggle", toggleProj);
  server.begin();
}

void loop() {
  server.handleClient();

  // Baca sensor
  int pir = digitalRead(PIR_PIN);
  int ldr = analogRead(LDR_PIN); // Nilai 0–4095 (gelap → terang)

  // Otomatisasi lampu: nyalakan jika ada gerak & gelap
  if (pir == HIGH && ldr < 2000 && !lampState) {
    lampState = true;
    digitalWrite(RELAY_LAMP, LOW);
    sendTelegram("💡 Lampu otomatis menyala (ada orang & gelap)");
  } else if (pir == LOW && lampState) {
    // Tunda matikan lampu 2 menit setelah tidak ada gerak
    static unsigned long lastMotion = 0;
    if (lastMotion == 0) lastMotion = millis();
    if (millis() - lastMotion > 120000) {
      lampState = false;
      digitalWrite(RELAY_LAMP, HIGH);
      sendTelegram("💡 Lampu otomatis dimatikan (tidak ada orang)");
      lastMotion = 0;
    }
  } else if (pir == HIGH) {
    // Reset timer saat ada gerak
    static unsigned long lastMotion = 0;
    lastMotion = millis();
  }

  delay(100);
}

Diagram Koneksi (Sederhana)

ESP32 ──┬── PIR OUT → GPIO13
        ├── LDR → GPIO34 (dengan resistor pull-down 10kΩ ke GND)
        ├── Relay IN1 → GPIO25 → Lampu
        ├── Relay IN2 → GPIO26 → Proyektor
        └── Relay IN3 → GPIO27 → Kipas/AC

Relay VCC → 5V, GND → GND
Perangkat listrik 220V dihubungkan ke terminal NO (Normally Open) relay