#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "HX711.h"
#include <Servo.h>

// LCD I2C (alamat umum 0x27, 16x2)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// HX711 Load Cell
#define DOUT PA2
#define CLK  PA3
HX711 scale;

// Ultrasonik
#define TRIG_PIN PA8
#define ECHO_PIN PA9

// PIR
#define PIR_PIN PA1

// Buzzer aktif LOW
#define BUZZER_PIN PA0

// Servo
Servo conveyorServo;
#define SERVO_PIN PB10

// LCD I2C pins
#define SDA_PIN PB7
#define SCL_PIN PB6

int botolCount = 0;
float beratMin = 1.0; // Gram
float beratMax = 2.0; // Gram

void setup() {
  Serial.begin(9600);

  // Inisialisasi I2C
  Wire.begin(SDA_PIN, SCL_PIN);
  lcd.init();
  lcd.backlight();

  // Pin setup
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, HIGH); // buzzer OFF (aktif LOW)

  conveyorServo.attach(SERVO_PIN);
  conveyorServo.write(0); // Posisi awal servo

  scale.begin(DOUT, CLK);
  scale.set_scale(); // Kalibrasi jika perlu
  scale.tare();      // Nol-kan beban

  lcd.setCursor(0, 0);
  lcd.print("Sistem Siap...");
  delay(1000);
  lcd.clear();
}

void loop() {
  // Cek keberadaan botol dengan ultrasonik
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;

  if (distance < 10.0) {
    botolCount++;
    lcd.setCursor(0, 0);
    lcd.print("Botol ke-");
    lcd.print(botolCount);
    Serial.print("Botol ke-"); Serial.println(botolCount);

    delay(1000); // Beri waktu botol diam di atas load cell

    // Baca berat botol
    float berat = scale.get_units(10);
    Serial.print("Berat: "); Serial.println(berat);

    lcd.setCursor(0, 1);
    lcd.print("Berat: ");
    lcd.print(berat, 1);
    lcd.print("g   "); // spacing supaya rapi

    if (berat < beratMin || berat > beratMax) {
      // Berat tidak sesuai
      digitalWrite(BUZZER_PIN, LOW);  // Buzzer ON (aktif LOW)
      lcd.setCursor(0, 1);
      lcd.print("Berat TIDAK OK ");
      Serial.println("Berat tidak sesuai!");
      delay(2000);
      digitalWrite(BUZZER_PIN, HIGH); // Buzzer OFF
    } else {
      // Berat sesuai
      int pirStatus = digitalRead(PIR_PIN);
      if (pirStatus == HIGH) {
        lcd.setCursor(0, 1);
        lcd.print("Berat OK. Kirim ");
        conveyorServo.write(90);
        delay(1500);
        conveyorServo.write(0);
      } else {
        lcd.setCursor(0, 1);
        lcd.print("Tunggu PIR...   ");
      }
    }

    delay(1000);
    lcd.clear();
  }
}