/**
   Arduino Calculator

   Copyright (C) 2020, Uri Shaked.
   Released under the MIT License.
*/

#include <LiquidCrystal.h>
#include <MsTimer2.h>

/* Display */
const int rs = 7, en = 6, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

/* Buttons */
const int hourButton = 8;
const int minuteButton = 9;
const int secondButton = 10;
const int zeroButton = 11;


int Sec = 57, Min = 01, Hour = 16;

void timer0() {
  Sec++;
  if (60 <= Sec) {
    Sec = 0;
    Min++;
  }

  if (60 <= Min) {
    Min = 0;
    Hour++;
  }

  if (24 <= Hour) {
    Hour = 0;
  }
}

void setup() {
  pinMode(hourButton, INPUT_PULLUP);
  pinMode(minuteButton, INPUT_PULLUP);
  pinMode(secondButton, INPUT_PULLUP);
  pinMode(zeroButton, INPUT_PULLUP);

  MsTimer2::set(1000, timer0);
  MsTimer2::start();
  lcd.begin(16, 2);
  lcd.clear();
}

void Click(){
  if (LOW==digitalRead(hourButton)) {
    delay(20);
    if(LOW==digitalRead(hourButton)){
          Hour++;
    }
    while(LOW==digitalRead(hourButton)){;};

  }

  if (LOW==digitalRead(minuteButton)) {
    delay(20);
    if (LOW==digitalRead(minuteButton)) {
    Min++;
    }
    while(LOW==digitalRead(minuteButton)){;};
  }

  if (LOW==digitalRead(secondButton)) {
    delay(20);
    if (LOW==digitalRead(secondButton)) {
    Sec++;
    }
    while(LOW==digitalRead(secondButton)){;};
  }

  if (LOW==digitalRead(zeroButton)) {
    delay(20);
    if (LOW==digitalRead(zeroButton)) {
    Hour=0;
    Min=0;
    Sec=0;
    }
    while(LOW==digitalRead(zeroButton)){;};
  }
}

void Write(){
  lcd.setCursor(0, 0);
  lcd.print("GongZheng,202322");

  lcd.setCursor(0, 1);
  lcd.print("41436: ");
}

void Show(){
  char timeStr[9];
  sprintf(timeStr, "%02d:%02d:%02d", Hour, Min, Sec);
  lcd.print(timeStr);
}

void loop() {
  Write();

  Click();

  Show();
}