PROJEK FAHRIN: Membangunkan Energy Saver System bagi sebuah bilik: lampu automatik menyala bila ada orang masuk dan padam bila bilik kosong, projek FYP pelajar

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 Berikut ialah pelan lengkap untuk membangunkan Energy Saver System bagi sebuah bilik: lampu automatik menyala bila ada orang masuk dan padam bila bilik kosong.

1) Objektif & Prinsip Kerja

• Objektif: Kurangkan pembaziran tenaga dengan mengawal lampu secara automatik.

• Logik asas:

  • Bila penghuni > 0 → lampu ON

  • Bila penghuni = 0 (selepas tempoh tunggu) → lampu OFF

• Pilihan sensor:

  1. PIR (simple, murah) – kesan pergerakan; risiko salah padam bila orang statik terlalu lama.

  2. Radar gelombang mikro/ultrasonik – sensitif, tembus bahan nipis; boleh lebih “noisy”.

  3. Pengiraan orang (disyorkan untuk “seorang atau lebih”) – dua beam IR / ToF di pintu (kira IN/OUT).

  4. LDR/ToF untuk cahaya ambien – elak menyalakan lampu jika bilik sudah terang.

Untuk memenuhi syarat “menyala jika seorang atau lebih, padam bila tiada”, kaedah pengiraan orang (dual-beam IN/OUT) adalah paling tepat.

2) Senibina Sistem (cadangan)

• Pengawal: Arduino Uno / Nano / ESP32 (jika mahu Wi-Fi & logging).

• Sensor pintu (kira orang): 2 × IR break-beam (A & B) dipasang selari ±15–20 cm jarak antara pasangan LED pemancar & penerima.

• Sensor cahaya: LDR + pembahagi voltan (atau modul BH1750).

• Pemacu lampu AC: Relay 1-channel (opto-isolate) / SSR / contactor mini (jika beban tinggi).

• Bekalan kuasa: SMPS 230VAC→5VDC (dalam kotak bertutup).

• Butang manual override (optional): Togol ON, AUTO, OFF.

• Penunjuk: LED status / paparan kecil (optional).

3) Aliran Logik (flow)

1. Inisialisasi pembilang occupancy = 0.

2. Pantau turutan beam:

   • A→B terputus berturutan = IN → occupancy++

   • B→A terputus berturutan = OUT → occupancy-- (bawah minimum 0 dikekang).

3. Jika occupancy > 0 dan lux < threshold → Lampu ON.

4. Jika occupancy == 0 → mula timer idle (cth 3–5 min); tamat timer → Lampu OFF.

5. Jika override: patuh mod override.

6. Debounce & penapisan untuk elak bacaan palsu.

4) Susun Atur Perkakasan (ringkas)

• Beam A & B dipasang pada bingkai pintu: penerima menghadap pemancar (garisan jelas).

• LDR di dinding/ceiling yang menerima cahaya bilik, bukan cahaya luar secara terus.

• Relay memutuskan talian Live ke lampu; Neutral kekal.

• Semua sambungan AC dalam kotak junction dengan terminal berpenebat (Keselamatan!).

Malaysia: 230 V, 50 Hz – WAJIB patuhi standard pendawaian & MCB/ELCB sedia ada. Jika tidak mahir AC, minta juruelektrik bertauliah.

5) Bahan (BOM) ringkas

• 1× Arduino/ESP32

• 2× IR break-beam modules (pemancar+receiver)

• 1× LDR + resistor 10–100 kΩ (atau modul lux BH1750)

• 1× Relay module 1-channel (5 V, opto) / SSR

• 1× SMPS 5 V 2 A

• Wayar dupont, breadboard/kotak projek, fius kecil (optional), butang toggle (optional)

6) Parameter Disyorkan

• Threshold lux: 200–300 lux (laras ikut suasana).

• Idle timeout (tiada orang): 180–300 s (3–5 min).

• Debounce beam: 30–80 ms.

• Ketinggian beam: ~90–110 cm dari lantai (laras untuk kanak-kanak/dewasa).

7) Pseudokod

occupancy = 0
lamp_on = false
last_empty_time = now()

loop:
  read beamA, beamB, lux, mode_switch

  if sequence A then B broken within window -> occupancy++
  if sequence B then A broken within window -> occupancy = max(0, occupancy-1)

  if mode = AUTO:
     if occupancy > 0 and lux < LUX_TH:
        lamp_on = true
     if occupancy == 0:
        if now() - last_change_to_zero >= IDLE_TIMEOUT:
           lamp_on = false
     if occupancy changed to 0:
        last_change_to_zero = now()

  if mode = ON:  lamp_on = true
  if mode = OFF: lamp_on = false

  write relay = lamp_on

8) Contoh Kod Arduino (dual-beam + LDR + relay)

// Pin assignment
const int BEAM_A_PIN = 2;      // IR receiver A (use INPUT_PULLUP)
const int BEAM_B_PIN = 3;      // IR receiver B
const int RELAY_PIN  = 8;      // Relay module (LOW/ACTIVE depends module)
const int LDR_PIN    = A0;     // LDR analog
const int MODE_SW1   = 4;      // optional: ON
const int MODE_SW2   = 5;      // optional: OFF (else AUTO)

volatile int occupancy = 0;
bool lampOn = false;

const unsigned long DEBOUNCE_MS   = 60;
const unsigned long SEQ_WINDOW_MS = 800; // max time between A and B for one pass
const unsigned long IDLE_TIMEOUT  = 240000UL; // 4 min
const int LUX_THRESHOLD_ADC = 450; // kalibrasi ikut rintangan LDR

unsigned long lastZeroTime = 0;
unsigned long lastBreakA = 0, lastBreakB = 0;
bool aBroken = false, bBroken = false;

void setup() {
  pinMode(BEAM_A_PIN, INPUT_PULLUP);
  pinMode(BEAM_B_PIN, INPUT_PULLUP);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(MODE_SW1, INPUT_PULLUP);
  pinMode(MODE_SW2, INPUT_PULLUP);

  digitalWrite(RELAY_PIN, LOW); // relay OFF awal
  Serial.begin(115200);
}

bool beamBroken(int pin){
  // Receiver biasanya LOW bila beam TERPUTUS (bergantung modul)
  return digitalRead(pin) == LOW;
}

void loop() {
  unsigned long now = millis();

  // --- baca beam dengan debounce ringkas ---
  static unsigned long la = 0, lb = 0;
  static bool aState = false, bState = false;

  bool aNow = beamBroken(BEAM_A_PIN);
  if (aNow != aState && (now - la) > DEBOUNCE_MS) {
    aState = aNow; la = now;
    if (aState) { // baru terputus
      lastBreakA = now; aBroken = true;
      // check turutan A->B (IN)
      if (bBroken == false && (now - lastBreakB) > SEQ_WINDOW_MS) {
        // tunggu B
      }
    }
  }

  bool bNow = beamBroken(BEAM_B_PIN);
  if (bNow != bState && (now - lb) > DEBOUNCE_MS) {
    bState = bNow; lb = now;
    if (bState) { // baru terputus
      lastBreakB = now; bBroken = true;
    }
  }

  // --- logik turutan ---
  if (aBroken && bBroken) {
    if (lastBreakA < lastBreakB && (lastBreakB - lastBreakA) <= SEQ_WINDOW_MS) {
      occupancy++;                                // IN
      Serial.println("IN"); 
    } else if (lastBreakB < lastBreakA && (lastBreakA - lastBreakB) <= SEQ_WINDOW_MS) {
      occupancy = max(0, occupancy - 1);          // OUT
      Serial.println("OUT");
    }
    aBroken = bBroken = false; // reset
    if (occupancy == 0) lastZeroTime = now;
  }

  // --- baca mode ---
  bool forceOn  = digitalRead(MODE_SW1) == LOW; // aktif bila ditekan (ke GND)
  bool forceOff = digitalRead(MODE_SW2) == LOW;

  int ldr = analogRead(LDR_PIN);

  // --- kawal lampu ---
  if (forceOn) {
    lampOn = true;
  } else if (forceOff) {
    lampOn = false;
  } else {
    // AUTO
    if (occupancy > 0 && ldr > LUX_THRESHOLD_ADC) {
      lampOn = false; // bilik terang: tak perlu lampu
    } else if (occupancy > 0) {
      lampOn = true;
    } else { // occupancy == 0
      if (now - lastZeroTime >= IDLE_TIMEOUT) lampOn = false;
    }
  }

  // Sesuaikan logik relay: sesetengah modul aktif LOW
  digitalWrite(RELAY_PIN, lampOn ? HIGH : LOW);

  // Debug ringkas
  static unsigned long lastPrint = 0;
  if (now - lastPrint > 1000) {
    lastPrint = now;
    Serial.print("Occ="); Serial.print(occupancy);
    Serial.print(" LDR="); Serial.print(ldr);
    Serial.print(" Lamp="); Serial.println(lampOn ? "ON" : "OFF");
  }
}

Nota: Nilai LUX_THRESHOLD_ADC perlu ditala mengikut rintangan LDR & suasana cahaya. Jika guna modul BH1750, tukar kepada bacaan lux sebenar (cth if (lux < 250)).

9) Pengujian & Penalaan

1. Uji turutan: melintas dari luar→dalam (A→B) bertambah; dari dalam→luar (B→A) berkurang.

2. Uji pintu sempit/ramai serentak: kecilkan SEQ_WINDOW_MS jika kiraan berganda palsu.

3. Uji statik: duduk tanpa bergerak; lampu kekal ON kerana occupancy > 0.

4. Uji cahaya siang: laras LUX_THRESHOLD.

5. Uji override: pastikan ON/AUTO/OFF berfungsi.

10) Keselamatan & Kepatuhan

• Pisahkan ruang AC dan DC dalam kotak projek.

• Gunakan fius kecil pada sisi AC untuk relay/contactor jika sesuai.

• Pastikan modul relay berlabel 250VAC dan arus melebihi arus lampu.

• Ikuti piawaian MS IEC & amalan pendawaian tempatan; guna konduit/terminal berpenutup.

........................................................................................................................................

kod penuh ESP32 + BH1750 + Web UI dalam canvas di sebelah.

Ringkas cara guna:

1. Wiring ikut nota dalam komen kod (pin dinyatakan).

2. Flash ke ESP32 (Arduino IDE): pasang library BH1750.

3. ESP32 akan buka hotspot EnergySaver-AP (password: esp32setup). Sambung Wi-Fi dan buka http://192.168.4.1/.

4. Di paparan web, anda boleh lihat Occupancy, Lux, Lamp status serta ubah Mode (AUTO/ON/OFF), Lux threshold, dan Idle timeout.

Tip pemasangan:

• Pastikan beam A dahulu kemudian B untuk masuk; B→A untuk keluar.

• Lindungi sensor IR daripada cahaya matahari terus.

• Relay mestilah sesuai dengan beban lampu; kerja AC 230 V wajib oleh juruelektrik bertauliah.

/*

ESP32 Energy Saver System — Dual-Beam People Counter + Ambient Light (BH1750) + Web UI

*/

#include <WiFi.h>

#include <WebServer.h>

#include <Wire.h>

#include <BH1750.h>

const int PIN_BEAM_A = 18;

const int PIN_BEAM_B = 19;

const int PIN_RELAY  = 23;

const bool RELAY_ACTIVE_HIGH = true;

const char* AP_SSID = "EnergySaver-AP";

const char* AP_PASS = "esp32setup";

WebServer server(80);

BH1750 lightMeter;

volatile int occupancy = 0;

unsigned long lastZeroTime = 0;

int LUX_THRESHOLD = 250;

unsigned long IDLE_TIMEOUT_MS = 240000UL;

const unsigned long DEBOUNCE_MS = 60;

const unsigned long SEQ_WINDOW_MS = 800;

enum Mode {AUTO=0, FORCE_ON=1, FORCE_OFF=2};

Mode mode = AUTO;

bool lampOn = false;

unsigned long lastBreakA = 0, lastBreakB = 0;

bool aBroken = false, bBroken = false;

bool aState = false, bState = false;

unsigned long la = 0, lb = 0;

bool beamBroken(int pin){ return digitalRead(pin) == LOW; }

float readLux(){ return lightMeter.measurementReady() ? lightMeter.readLightLevel() : -1.0f; }

void setRelay(bool on){ digitalWrite(PIN_RELAY, RELAY_ACTIVE_HIGH ? (on ? HIGH : LOW) : (on ? LOW : HIGH)); }

String modeToString(Mode m){ return m==AUTO?"AUTO":(m==FORCE_ON?"ON":"OFF"); }

void handleRoot(){

  float lux = readLux();

  String html = "<html><body><h2>ESP32 Energy Saver</h2>";

  html += "Mode: "+modeToString(mode)+"<br>Occupancy: "+String(occupancy)+"<br>Lamp: "+(lampOn?"ON":"OFF")+"<br>Lux: "+String(lux,1)+"<br>";

  html += "<form action='/set' method='get'>Mode <select name='mode'><option value='auto'"+(mode==AUTO?" selected":"")+">AUTO</option><option value='on'"+(mode==FORCE_ON?" selected":"")+">ON</option><option value='off'"+(mode==FORCE_OFF?" selected":"")+">OFF</option></select><br>Lux threshold <input type='number' name='lux' value='"+String(LUX_THRESHOLD)+"'><br>Idle timeout (s) <input type='number' name='idle' value='"+String(IDLE_TIMEOUT_MS/1000)+"'><br><button type='submit'>Save</button></form></body></html>";

  server.send(200, "text/html", html);

}

void handleSet(){

  if (server.hasArg("mode")){

    String m = server.arg("mode"); m.toLowerCase();

    if (m=="auto") mode = AUTO; else if (m=="on") mode = FORCE_ON; else if (m=="off") mode = FORCE_OFF;

  }

  if (server.hasArg("lux")) LUX_THRESHOLD = server.arg("lux").toInt();

  if (server.hasArg("idle")) IDLE_TIMEOUT_MS = server.arg("idle").toInt()*1000UL;

  server.sendHeader("Location", "/"); server.send(302, "text/plain", "Updated");

}

void handleApi(){

  float lux = readLux();

  String json = "{\"mode\":\""+modeToString(mode)+"\",\"occupancy\":"+String(occupancy)+",\"lamp\":\""+(lampOn?"ON":"OFF")+"\",\"lux\":"+String(lux,1)+",\"threshold\":"+String(LUX_THRESHOLD)+",\"idle_s\":"+String(IDLE_TIMEOUT_MS/1000)+"}";

  server.send(200, "application/json", json);

}

void setup(){

  Serial.begin(115200);

  pinMode(PIN_BEAM_A, INPUT_PULLUP);

  pinMode(PIN_BEAM_B, INPUT_PULLUP);

  pinMode(PIN_RELAY, OUTPUT);

  setRelay(false);

  Wire.begin(21,22);

  lightMeter.begin(BH1750::CONTINUOUS_HIGH_RES_MODE);

  WiFi.mode(WIFI_AP);

  WiFi.softAP(AP_SSID, AP_PASS);

  server.on("/", handleRoot);

  server.on("/set", handleSet);

  server.on("/api/status", handleApi);

  server.begin();

  lastZeroTime = millis();

}

void loop(){

  unsigned long now = millis();

  server.handleClient();

  bool aNow = beamBroken(PIN_BEAM_A);

  if (aNow != aState && (now - la) > DEBOUNCE_MS){ aState = aNow; la = now; if (aState){ lastBreakA = now; aBroken = true; }}

  bool bNow = beamBroken(PIN_BEAM_B);

  if (bNow != bState && (now - lb) > DEBOUNCE_MS){ bState = bNow; lb = now; if (bState){ lastBreakB = now; bBroken = true; }}

  if (aBroken && bBroken){

    if (lastBreakA < lastBreakB && (lastBreakB - lastBreakA) <= SEQ_WINDOW_MS) occupancy++;

    else if (lastBreakB < lastBreakA && (lastBreakA - lastBreakB) <= SEQ_WINDOW_MS) occupancy = max(0, occupancy-1);

    aBroken = bBroken = false;

    if (occupancy == 0) lastZeroTime = now;

  }

  float lux = readLux();

  if (mode == FORCE_ON) lampOn = true;

  else if (mode == FORCE_OFF) lampOn = false;

  else {

    bool darkEnough = (lux < 0) ? true : (lux < LUX_THRESHOLD);

    if (occupancy > 0 && darkEnough) lampOn = true;

    else if (occupancy == 0 && (now - lastZeroTime >= IDLE_TIMEOUT_MS)) lampOn = false;

    else if (occupancy > 0 && !darkEnough) lampOn = false;

  }

  setRelay(lampOn);

  static unsigned long lastPrint = 0;

  if (now - lastPrint > 1000){

    lastPrint = now;

    Serial.printf("Occ=%d Lux=%.1f Mode=%s Lamp=%s\n", occupancy, lux, modeToString(mode).c_str(), lampOn?"ON":"OFF");

  }

}