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

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int buttonPins[4] = {2, 3, 4, 5};
const int ledPins[4] = {6, 7, 8, 9};
const int potPins[4] = {A0, A1, A2, A3};

bool buttonStates[4] = {false, false, false, false};

void setup() {
    lcd.init();
    lcd.backlight();
    
    for (int i = 0; i < 4; i++) {
        pinMode(buttonPins[i], INPUT_PULLUP);
        pinMode(ledPins[i], OUTPUT);
    }
    
    lcd.setCursor(0, 0);
    lcd.print("HMI System Ready");
    delay(2000);
    lcd.clear();
}

void loop() {
    lcd.setCursor(0, 0);
    lcd.print("Btn: ");
    
    for (int i = 0; i < 4; i++) {
        if (digitalRead(buttonPins[i]) == LOW) {
            buttonStates[i] = true;
        } else {
            buttonStates[i] = false;
        }
        
        digitalWrite(ledPins[i], buttonStates[i] ? HIGH : LOW);
        
        lcd.setCursor(5 + i, 0);
        lcd.print(buttonStates[i] ? "1" : "0");
    }
    
    lcd.setCursor(0, 1);
    lcd.print("V: ");
    for (int i = 0; i < 4; i++) {
        int potValue = analogRead(potPins[i]);
        float voltage = (potValue / 1023.0) * 5;
        
        lcd.setCursor(3 + (i * 4), 1);
        lcd.print(voltage, 1);
        lcd.print("V");
    }
    
    delay(200);
}