#include <HX711.h>
#include <ESP32Servo.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>


// --- Konstanta Pin ---
#define TRIG_PIN 26         // GPIO untuk Trigger HC-SR04
#define ECHO_PIN 25         // GPIO uAntuk Echo HC-SR04
#define SERVO_PIN 13        // GPIO PWM untuk Servo
#define HX711_DT 33         // GPIO untuk Data HX711
#define HX711_SCK 32        // GPIO untuk Clock HX711
#define OLED_SDA 21         // GPIO SDA OLED (I2C)
#define OLED_SCL 22         // GPIO SCL OLED (I2C)


// --- OLED Display ---
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


// --- Objek ---
HX711 scale;
Servo servo;


const float calibration_factor = 7050.0;  // Kalibrasi load cell
const float harga_per_kg = 3000.0;        // Harga per kilogram
float berat = 0;
float rupiah = 0;
long duration;
float distance;


void setup() {
  Serial.begin(115200);
  Serial.println("Inisialisasi sistem...");


  // --- Inisialisasi Servo ---
  servo.attach(SERVO_PIN);
  servo.write(0); // Tutup di awal


  // --- Inisialisasi Load Cell ---
  scale.begin(HX711_DT, HX711_SCK);
  scale.set_scale(calibration_factor);
  scale.tare(); // Reset ke 0


  // --- Inisialisasi Sensor Ultrasonik ---
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);


  // --- Inisialisasi I2C untuk OLED khusus ESP32 ---
  Wire.begin(OLED_SDA, OLED_SCL);


  // --- Inisialisasi OLED ---
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Alamat I2C 0x3C
    Serial.println("Gagal inisialisasi OLED");
    while (true);
  }


  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Sistem Siap!");
  display.display();
  delay(1000);
}


void loop() {
  // --- Baca Berat ---
  berat = scale.get_units();
  if (berat < 0) berat = 0;


  // --- Baca Jarak ---
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;


  // --- Hitung Total Harga ---
  rupiah = berat * harga_per_kg;


  // --- Tampilan OLED ---
  display.clearDisplay();
  display.setCursor(0, 0);


  if (berat >= 1.0) {
    display.println("Berat:");
    display.print(berat, 2); display.println(" kg");


    display.println("Harga:");
    display.print("Rp "); display.println((long)rupiah);


    servo.write(90); // Buka
  } else {
    display.println("Tunggu Sampah...");
    display.print("Jarak: ");
    display.print(distance, 0); display.println(" cm");


    servo.write(0); // Tutup
  }


  display.display();


  // --- Debug Monitor Serial ---
  Serial.print("Berat: "); Serial.print(berat); Serial.print(" kg | ");
  Serial.print("Jarak: "); Serial.print(distance); Serial.print(" cm | ");
  Serial.print("Rp: "); Serial.println(rupiah);


  delay(500);
}