#include <HX711.h>

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 5;
const int LOADCELL_SCK_PIN = 18;

HX711 scale;
// initialize OLED
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

//buzzer setup
#define  freq  2000
#define  channel  0
#define resolution  8

void setup() {
  Serial.begin(115200);
  //buzzer ------------------->
  ledcSetup(channel, freq, resolution);
  ledcAttachPin(12, channel);
  //OLED --------------------->
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(1000);
  
  //Load Cell -------------------------------->
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  Serial.println("HX711 LOAD CELL");
  Serial.println("Initialize...");

  loadcell_start();
}

void loop() {
  //calibration_setup(); //kalibrasi load cell
  loadcell_read();
  

}

void calibration_setup (){ //untuk mencari faktor kalibrasi
  if (scale.is_ready()) {
    scale.set_scale();    
    Serial.println("Tare... remove any weights from the scale.");
    delay(4000);
    scale.tare();
    Serial.println("Tare done...");
    Serial.print("Place a known weight on the scale...");
    delay(6000);
    long reading = scale.get_units(10);
    Serial.print("Result: ");
    Serial.println(reading);
    Serial.println(reading/43);//calibration factor = result/berat sesungguhnya
    delay(1000);
  } 
  else {
    Serial.println("HX711 not found.");
  }
  delay(1000);

}

void loadcell_start(){ //meng setup load cell sebelum digunakan
  Serial.println("Before setting up the scale:");
  Serial.print("read: \t\t");
  Serial.println(scale.read());      // print a raw reading from the ADC

  
  Serial.print("read average: \t\t");
  Serial.println(scale.read_average(20));   // print the average of 20 readings from the ADC

  Serial.print("get value: \t\t");
  Serial.println(scale.get_value(5));   // print the average of 5 readings from the ADC minus the tare weight (not set yet)

  Serial.print("get units: \t\t");
  Serial.println(scale.get_units(5), 1);  // print the average of 5 readings from the ADC minus tare weight (not set) divided
            // by the SCALE parameter (not set yet)
         
  scale.set_scale(419);
  //scale.set_scale(-9334);                      // this value is obtained by calibrating the scale with known weights; see the README for details
  scale.tare();               // reset the scale to 0

  Serial.println("After setting up the scale:");

  
  Serial.print("read: \t\t");
  Serial.println(scale.read());                 // print a raw reading from the ADC

  Serial.print("read average: \t\t");
  Serial.println(scale.read_average(20));       // print the average of 20 readings from the ADC

  Serial.print("get value: \t\t");
  Serial.println(scale.get_value(5));   // print the average of 5 readings from the ADC minus the tare weight, set with tare()

  Serial.print("get units: \t\t");
  Serial.println(scale.get_units(5), 1);        // print the average of 5 readings from the ADC minus tare weight, divided
            // by the SCALE parameter set with set_scale
  
  Serial.println("Readings:");
}

void loadcell_read(){ //membaca nilai dari load cell
  Serial.print("Weight:\t");
  Serial.println(scale.get_units(), 1);

  display.clearDisplay();

  display.setTextSize(1.95);
  display.setTextColor(WHITE);
  display.setCursor(18, 25);
  // Display static text
  display.print("WEIGHT: ");
  display.setCursor(63, 25);
  display.print(scale.get_units(), 1);
  display.setCursor(98, 25);
  display.println("Kg");
  display.display(); 

  if(int(scale.get_units(1)) > 29){ //buzz ketika berat lebih dari 29
    ledcWriteTone(channel, 2000);
    ledcWrite(channel,125);
  }else{
    ledcWrite(channel,0);
  }

  delay(2000);
}