#include <LiquidCrystal_I2C.h>

byte currentButtonState = 0;
byte prevButtonState = 99; 

LiquidCrystal_I2C lcd(0x27,20,4);  

void setup()
{
  
  lcd.init();
  for (int i = 0; i < 8; i++) {
    pinMode(i, INPUT_PULLUP);
  } 
  lcd.backlight();

}


void loop()
{
 
  currentButtonState = 0;
  for (int i = 0; i < 8; i++) {
    currentButtonState |= (!digitalRead(i)) << i;
  } 
  if (prevButtonState != currentButtonState) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("0x");
    if (currentButtonState < 16) {
      lcd.print("0"); 
    }
    lcd.print(currentButtonState, HEX);

    for (int i = 0; i < 8; i++) {
      lcd.setCursor((7 - i), 1);
      if (bitRead(currentButtonState, i)) {
        lcd.print("1");
      } else {
        lcd.print("0");
      } 
    } 

    switch (currentButtonState) {
      case B10000001:
        lcd.noBacklight();
        break;
      case B01000010:
        lcd.backlight();
        break;

    } 

  } 

  prevButtonState = currentButtonState;
}

void startTimer() {
  TCCR1A = 0;
  TCCR1B = bit(CS10);
  TCNT1 = 0;
}

void endTimerAndPrint() {
  unsigned int cycles = TCNT1;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Cyc: ");
  lcd.print(cycles - 1);
  lcd.setCursor(0, 1);
  lcd.print("Mic: ");
  lcd.print((float)(cycles - 1) / 16);

}