#include <TM1637Display.h>
#define rel 2
#define start 3
#define reset 4
//#define set 7
#define decr 8
#define incr 9
#define DIO 5
#define CLK 6

int sec,mins,buffer;

TM1637Display display(CLK, DIO);
 
void setup() 
{
   pinMode(rel, OUTPUT);
   pinMode(start, INPUT_PULLUP);
   pinMode(reset, INPUT_PULLUP);
   //pinMode(set, INPUT_PULLUP);
   pinMode(incr, INPUT_PULLUP);
   pinMode(decr, INPUT_PULLUP);
   
   display.setBrightness(0x0f);
   display.showNumberDecEx(mins, 0b01000000, true,2,0);      
   display.showNumberDecEx(sec, 0b01000000, true,2,2); 
 
}

void loop() 
{
    if(digitalRead(start)==0)
    {
       sec=0;
       digitalWrite(rel,0);
       timer();
    }  

    if(digitalRead(reset)==0)
    {
       mins=buffer;
       sec=0;
       digitalWrite(rel, LOW);
       display.showNumberDecEx(mins, 0b01000000, true,2,0); 
       display.showNumberDecEx(sec, 0b01000000, true,2,2);
       delay(300);
    }
        
    if(digitalRead(incr)==0)
    {
      mins++;
      delay(200);
      display.showNumberDecEx(mins, 0b01000000, true,2,0); 
      buffer=mins;
    }
   
    if(digitalRead(decr)==0)
    {
      mins--;
      delay(200);
      display.showNumberDecEx(mins, 0b01000000, true,2,0); 
      buffer=mins;
    }
    
    delay(50);
}

void timer()
{
   while(1)
   {
             
       display.showNumberDecEx(mins, 0b01000000, true,2,0); 
       display.showNumberDecEx(sec, 0b01000000, true,2,2);
      
       if(digitalRead(reset)==0)
       {
          mins=buffer;
          sec=0;
          digitalWrite(rel, LOW);
          display.showNumberDecEx(mins, 0b01000000, true,2,0); 
          display.showNumberDecEx(sec, 0b01000000, true,2,2);
          return;
       }
       delay(1000);
      
       if(sec==0)
       {
         sec=60;
         mins--;
         if(mins==-1)
         {
           digitalWrite(rel, HIGH);
           tone(10,1000);
           delay(2000);
           noTone(10);
           mins=buffer;
           sec--;
           return;
         }
              
       }
       sec--;
    }
   
}