#include <Wire.h>  

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int potPin = A2;

const int LdrPin = A3;

const int ledPin = 5;

const int LampPin = A0;

int potValue = 0;

int ldrValue = 0;

int threshold = 0;

volatile bool updateSensor = false;

void setup() {

  // put your setup code here, to run once:

  lcd.init();

  lcd.backlight();  

  pinMode(ledPin, OUTPUT);

  pinMode(LampPin, OUTPUT);

  lcd.setCursor(0, 0);

  lcd.print("Sistem Kontrol  ");

  lcd.setCursor(0, 1);

  lcd.print("Lampu Taman Auto");

  delay(3000);

  lcd.clear();

  setupTimer1_100ms();

}

void loop() {

  // put your main code here, to run repeatedly:

  if (updateSensor) {

    updateSensor = false;

    potValue = analogRead(potPin);  

    int ldrRaw = analogRead(LdrPin);

    ldrValue = 1023 - ldrRaw;

    threshold = map(potValue, 0, 1023, 0, 1023);

    bool lampOn = ldrValue < threshold;

    digitalWrite(LampPin, lampOn ? HIGH : LOW);

    digitalWrite(ledPin, lampOn ? LOW : HIGH);

    lcd.setCursor(0, 0);

    lcd.print("POT: ");

    lcd.print(potValue);

    lcd.print("   LAMPU");

    lcd.setCursor(12, 1);

    lcd.print(lampOn ? "ON  " : "OFF ");

    lcd.setCursor(0, 1);

    lcd.print("LDR: ");

    lcd.print(ldrValue);

    int len = String(ldrValue).length();

    for (int i = 0; i < (9 - len - 4); i++) lcd.print(" ");

  }

}

void setupTimer1_100ms() {

  noInterrupts();

  TCCR1A = 0;

  TCCR1B = 0;

  TCNT1  = 0;

  OCR1A = 1562;

  TCCR1B |= (1 << WGM12);

  TCCR1B |= (1 << CS12) | (1 << CS10);

  TIMSK1 |= (1 << OCIE1A);

  interrupts();

}

ISR(TIMER1_COMPA_vect) {

  updateSensor = true;

}