int count = 0;

void ARDUINO_ISR_ATTR isr(void) {
  count++;
}


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(26, INPUT_PULLUP);
  attachInterrupt(26, isr, RISING);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(200); // this speeds up the simulation
  Serial.println(count);
}