#define PB1 10   //Counter

#define Led 8    //Counter


bool pb1_pressed;

int Counter = 0;
int Counter_buff = 0;

unsigned long T_nowP1;
unsigned long DurationP1 = 3000;  // on off each timer



void setup() {
  Serial.begin(9600);
  pinMode(PB1, INPUT);
  pinMode(Led, OUTPUT);
}

void loop()
{
  if (digitalRead(PB1)) {
    if (!pb1_pressed) {
      Counter++;

      pb1_pressed = !pb1_pressed;
    }
  } else pb1_pressed = !pb1_pressed;



  if (Counter != 0 && (Counter % 3) == 0 && Counter != Counter_buff) {
    T_nowP1 = millis();
    digitalWrite(Led, true);
    Serial.println(Counter);
    Counter_buff = Counter;
  }

  if (digitalRead(Led) & (millis() - T_nowP1 > DurationP1)) {
  digitalWrite(Led, false);
  }

}