I need help with my countdown timer project!

Development Boards Arduino
19

I had a much closer look, and have noticed a few problems.

Firstly, your digits array is not properly initialised. You used “( )” not “{ }”. This is what it should be:

byte digits [10][8] = {
  // a b c d e f g .
  {1,1,1,1,1,1,0,0}, //0
  {0,1,1,0,0,0,0,0}, //1
  {1,1,0,1,1,0,1,0}, //2
  {1,1,1,1,0,0,1,0}, //3
  {0,1,1,0,0,1,1,0}, //4
  {1,0,1,1,0,1,1,0}, //5
  {1,0,1,1,1,1,1,0}, //6
  {1,1,1,0,0,0,0,0}, //7
  {1,1,1,1,1,1,1,0}, //8
  {1,1,1,1,0,1,1,0}  //9
};

Secondly, It wasn’t counting. The way you had written the program, seconds was always set to 59, and minutes never changed. Here is a changed version:

void updateCountingTime()
{
  static unsigned long lastMillis = 0; //Initial time is 0
  
  unsigned long m= millis(); //get the current time
  if (m> (lastMillis + 1000) && (timerSecond > 0 || timerMinute >0))
  {
    //if a second has passed, and there is time left on the clock
    digitalWrite(buzzerPin, HIGH);
    delay(10);
    digitalWrite(buzzerPin, LOW);
    if (timerSecond == 0)
    {
      //reached 0 seconds
      if(timerMinute > 0)
      {
        //if there are still minutes on the clock, reduce minutes by one and reset seconds to 59
        timerSecond = 59;
        timerMinute--;
      }
    } else {
      timerSecond--;
    }
    lastMillis = m; //update last clock time
  }
}

I haven’t got an display to test it with, but I output the value being sent to the setDigit() function over the serial port, and it appears to count down now as it should.