#include <HX711_ADC.h>
#include <EEPROM.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define button 8
int btnState = 0;
float newW = 0;
float newZero = 0;
float calo = 0;
//pins:
const int HX711_dout = 4; //mcu > HX711 dout pin
const int HX711_sck = 5; //mcu > HX711 sck pin

//HX711 constructor:
HX711_ADC LoadCell(HX711_dout, HX711_sck);

const int calVal_eepromAdress = 0;
unsigned long t = 0;

void setup() {
  pinMode(button, INPUT);
  Serial.begin(57600); delay(10);
  Serial.println();
  Serial.println("Starting...");
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Rice Scale");

  LoadCell.begin();
  //LoadCell.setReverseOutput(); //uncomment to turn a negative output value to positive
  float calibrationValue; // calibration value (see example file "Calibration.ino")
  //calibrationValue = 696.0; // uncomment this if you want to set the calibration value in the sketch
  EEPROM.get(calVal_eepromAdress, calibrationValue); // uncomment this if you want to fetch the calibration value from eeprom

  unsigned long stabilizingtime = 2000; // preciscion right after power-up can be improved by adding a few seconds of stabilizing time
  boolean _tare = true; //set this to false if you don't want tare to be performed in the next step
  LoadCell.start(stabilizingtime, _tare);
  if (LoadCell.getTareTimeoutFlag()) {
    Serial.println("Timeout, check MCU>HX711 wiring and pin designations");
    while (1);
  }
  else {
    LoadCell.setCalFactor(calibrationValue); // set calibration value (float)
    Serial.println("Startup is complete");
  }
}

void loop() {
  btnState = digitalRead(button);
  static boolean newDataReady = 0;
  const int serialPrintInterval = 0; //increase value to slow down serial print activity

  // check for new data/start next conversion:
  if (LoadCell.update()) newDataReady = true;

  // get smoothed value from the dataset:
  if (newDataReady) {
    if (millis() > t + serialPrintInterval) {
      float i = LoadCell.getData();
      if (btnState == 1) {
        newZero = i;
      }
      newW = i - newZero;
      if (newW < 1) {
        newW = 0;
      }
      calo = 1.30 * newW;
      Serial.print("Load_cell output val: ");
      Serial.println(newW);
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Weight:");
      lcd.print(newW);
      lcd.print(" g");
      lcd.setCursor(0, 1);
      lcd.print("Calories:");
      lcd.print(calo);
      lcd.print("     ");
      newDataReady = 0;
      t = millis();
    }
  }

  // receive command from serial terminal, send 't' to initiate tare operation:
  if (Serial.available() > 0) {
    char inByte = Serial.read();
    if (inByte == 't') LoadCell.tareNoDelay();
  }

  // check if last tare operation is complete:
  if (LoadCell.getTareStatus() == true) {
    Serial.println("Tare complete");
  }

}