//COUNTDOWN TIMER

#define start 12
#define stop 11

unsigned long setTime = 10;
unsigned long startTime =0;
unsigned long lastPress = 0;
unsigned long lastCount = 0; 

bool timerState = 0;

void setup() {

Serial.begin(115200);

pinMode(start, INPUT);
pinMode(stop, INPUT);

setTime = minToMilisec(setTime);
Serial.println(setTime);
}

void loop() {
  // put your main code here, to run repeatedly:

if(digitalRead(start) == 1 && millis() - lastPress > 500){
  lastPress = millis();
  if(startTime == 0){
    startTime = millis();
  }
  timerState = 1;
}

if(digitalRead(stop) == 1 && millis() - lastPress > 500){
  lastPress = millis();

  switch(timerState){
    case 0:
    startTime = 0;
    break;
    case 1:
    timerState = 0;
  }
}

switch(timerState){
  case 1:
  runCountDown();
}

}

void runCountDown(){

  unsigned long currentCount = (millis() - startTime)/1000;
  if(currentCount != lastCount && millis() - lastCount >= 900){
    lastCount = currentCount;

  if(millis() - startTime < setTime && (millis() - startTime) % 1000 == 0){

    lastCount = millis() - startTime;
    String timeDisplay;

    int time = (setTime - (millis() - startTime))/1000;
    int seconds = 0;
    int minutes = 0;

    while(time >= 60){
      time = time - 60;
      minutes ++;
    }

    seconds = time;

    if(seconds < 10){
      timeDisplay = String(minutes) + ":0" + String(seconds);
    } else {
      timeDisplay = String(minutes) + ":" + String(seconds);
    }

    Serial.println(timeDisplay);
  } else if(millis() - startTime >= setTime){
    startTime = 0;
  }
  }
}

unsigned long minToMilisec(unsigned long timeIn){
  unsigned long timeOut = timeIn *1000*60;
  return timeOut;
}