volatile boolean toggle = false;

void isr_5min() {
  toggle = true;
}

void setup() {
  pinMode(PA5, OUTPUT);
  pinMode(PA1, INPUT_PULLDOWN);
  attachInterrupt(digitalPinToInterrupt(PA1), isr_5min, FALLING);
}

void loop() {
  if (toggle) {
    digitalWrite(PA5, HIGH);
    delay(5000);
    toggle = false;
  } else {
    digitalWrite(PA5, HIGH);
    delay(200);
    digitalWrite(PA5, LOW);
    delay(200);
  }
}