#include <LiquidCrystal_I2C.h>

// constants won't change. They're used here to set pin numbers, etc.
const int buttonPin = 2;
const int ledPin = 15;
const int freq = 500; // in Hz
const int ledChannel = 0; // [0-15]
const int resolution = 8; // in bits

// variables will change:
bool currButtonStatus = false;
bool prevButtonStatus = false;
int lcdColumns = 16;
int lcdRows = 2;
int pwmVal = 0;
int count = 0;

// define the LCD
LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  

// to refresh the display with the current pwmVal
void displayLcd() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Medium");
  lcd.setCursor(0, 1);
  lcd.print("@syafiqza");
  lcd.setCursor(13, 0);
  lcd.print("PWM");
  lcd.setCursor(13, 1);
  lcd.print(pwmVal);
}

void setup() {
  // initialize the button pin as an input:
  pinMode(buttonPin, INPUT);
  // initialize the LED pin:
  ledcSetup(ledChannel, freq, resolution);
  ledcAttachPin(ledPin, ledChannel);
  // initialize LCD and turn on the backlight
  lcd.init();
  lcd.backlight();
  // first display the LCD
  displayLcd();
}

void loop() {
  currButtonStatus = digitalRead(buttonPin);
  if (currButtonStatus == HIGH) {
    if (prevButtonStatus == false) {
      // increment count when button pressed and set previous button state to on
      count++;
      prevButtonStatus = !prevButtonStatus;
    }
    // set the LED PWM and refresh the LCD as the pwmVal varies by [0, 127, 255]
    pwmVal = (int)(floor(256 * (count % 3) / 2) - ((count % 3) > 0));
    ledcWrite(ledChannel, pwmVal);
    displayLcd();
  } else {
    // turn off all LED and set 'previous' button state to off
    prevButtonStatus = false;
  }
  count %= 10;
}