#define PB1 10
#define Led1 7
int period = 5000;  //periode in ms
unsigned long time_now = 0;
bool button_pressed = false;
bool button_pressed2 = false;

void setup() {
  Serial.begin(9600);
  pinMode(PB1, INPUT);
  pinMode(Led1, OUTPUT);
}

void loop()
{
  if (digitalRead(PB1) && !button_pressed) {
    digitalWrite(Led1, HIGH);
    button_pressed = true;
    button_pressed2 = false;
    Serial.println("stage1");
  }
  if (!digitalRead(PB1) && button_pressed && !button_pressed2) {
    time_now = millis();
    button_pressed = false;
    button_pressed2 = true;
    Serial.println("stage2");
  }

  if (millis() - time_now > period && button_pressed2)
  {
    digitalWrite(Led1, LOW);
    button_pressed = false;
    button_pressed2 = false;
    Serial.println("stage3");
  } 
}