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

// Pin Definitions
#define DT 4
#define SCK 5
#define TARE_BUTTON 12
#define PLUS_BUTTON 13
#define MINUS_BUTTON 14
#define START_BUTTON 27
#define OFF_BUTTON 26
#define RELAY_PIN 23

// LCD Settings
LiquidCrystal_I2C lcd(0x27, 16, 2);

// HX711 Settings
HX711 scale;
float targetWeight = 20.0;  // Default target weight in grams
bool relayState = false;

void setup() {
  Serial.begin(115200);

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Initialize HX711
  scale.begin(DT, SCK);
  scale.set_scale();  // Calibrate scale here
  scale.tare();       // Reset scale to 0

  // Set up pins
  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);

  pinMode(TARE_BUTTON, INPUT_PULLUP);
  pinMode(PLUS_BUTTON, INPUT_PULLUP);
  pinMode(MINUS_BUTTON, INPUT_PULLUP);
  pinMode(START_BUTTON, INPUT_PULLUP);
  pinMode(OFF_BUTTON, INPUT_PULLUP);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Target: ");
  lcd.print(targetWeight, 2);
}

void loop() {
  float weight = scale.get_units();

  // Tare button
  if (digitalRead(TARE_BUTTON) == LOW) {
    scale.tare();
    updateDisplay();
    delay(300);
  }

  // Adjust target weight
  if (digitalRead(PLUS_BUTTON) == LOW) {
    targetWeight += 0.50;
    updateDisplay();
    delay(300);
  }
  if (digitalRead(MINUS_BUTTON) == LOW) {
    targetWeight -= 0.50;
    if (targetWeight < 0) targetWeight = 0;
    updateDisplay();
    delay(300);
  }

  // Start button
  if (digitalRead(START_BUTTON) == LOW) {
    relayState = true;
    digitalWrite(RELAY_PIN, HIGH);
    updateDisplay();
    delay(300);
  }

  // Turn off button
  if (digitalRead(OFF_BUTTON) == LOW) {
    relayState = false;
    digitalWrite(RELAY_PIN, LOW);
    updateDisplay();
    delay(300);
  }

  // Check weight and auto-off relay
  if (relayState && weight >= targetWeight) {
    relayState = false;
    digitalWrite(RELAY_PIN, LOW);
    updateDisplay();
  }
}

void updateDisplay() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Target: ");
  lcd.print(targetWeight, 2);
  lcd.print("g");

  lcd.setCursor(0, 1);
  lcd.print("Weight: ");
  lcd.print(scale.get_units(), 2);
  if (relayState) {
    lcd.print(" ON");
  } else {
    lcd.print(" OFF");
  }
}