const int led[8] = {PA5, PA6, PA7, PB6, PB7, PB8, PB9, PA0};
const int btn = PA0; 

byte counter = 0;          
unsigned long timer = 0;  

void setup() {
  for(int i=0; i<8; i++) pinMode(led[i], OUTPUT);
  pinMode(btn, INPUT_PULLUP);
}

void loop() {
  // Сброс по кнопке
  if(!digitalRead(btn)) { counter=0; show(); delay(200); }
  
 
  if(millis() - timer >= 1000) {
    timer = millis();
    counter++;          
    show();
  }
}


void show() {
  for(int i=0; i<8; i++) 
    digitalWrite(led[i], (counter>>i) & 1);
}