// Name: ABDUL KHALED ARAFAT
// ID: 190122
// Session: 2019-2020

// ***The green button is for START & PAUSE counter operation
// ***The red button is for RESET counter operation

// README : 
// As the button work as real-life physical button. 
// Sometimes pressing one single time actually pressed 
// two or more times, for this the display may not pause 
// while timer count is ongoing or vice-versa.
// ____________________________________________________

#include <TM1637.h>

int clk = 12, dio = 13, a[4];
unsigned long cnt = 0;

int st = 6, f = 0, b = 0, pp = 5;

TM1637 timer1(clk, dio);

void setup() {
  timer1.init();
  timer1.set(7);

  pinMode(st, INPUT);
  pinMode(pp, INPUT);

  allZero();
}

void loop() {
  if (digitalRead(pp) == HIGH) {
    myCounter();
  }
  
  if(digitalRead(st) == HIGH && f == 0) {
    cnt = 0;
    f = 1;
    allZero();
  }
  
  if(digitalRead(st) == LOW && f == 1) {
    cnt = 0;
    f = 0;
    allZero();
  }

}

void myCounter() {
  a[0] = cnt / 1000;
  a[1] = (cnt / 100) % 10;
  a[2] = (cnt / 10) % 10;
  a[3] = cnt % 10;

  for (int i = 0 ; i < 4 ; i++) {
    timer1.display(i, a[i]);
  }

  cnt++;
  if (cnt > 9999) {
    cnt = 0;
  }

  delay(100);
}

void allZero() {
  for (int i = 0 ; i < 4 ; i++) {
    timer1.display(i, 0);
  }
}