Blinking random objects in arrays

Processing Coding Questions
2

I managed to get them flashing but it’s way too fast, I’m hoping to get a slow blinking, I don’t know how to get any further than this pls help, anyway to make it blink slower? new parts is void blinkCheck(); and void count();

Mines[] mines = new Mines [10];
int count =1;
boolean blinkM = true;
int diameter= 30;
void setup() {
  size(1200, 600);
  for(int i = 0; i < mines.length; i++){
  mines[i] = new Mines ();
}
}


void draw() {
  background(255);
  for(int i = 0; i < mines.length; i++){
    mines[i].display();
}
blinkCheck();
count();
}



class Mines {
  float x;
  float y;
  

  Mines() {
    x = random(15, width - diameter);
    y = random(15, height - diameter);
    diameter = 30;
  }

  void display() {
    noStroke();
    fill(0);
    ellipse(x, y, diameter, diameter);
  }
}


void blinkCheck(){
  if(count % 2 == 1){
    blinkM = true;  }
    else {blinkM = false;}
    
   if (blinkM == true){
     diameter = 30; }
     else {diameter = 0;}
}

void count(){
  count++;
}