#define LED_PIN0 PA7   // LED connected to PA7
#define LED_PIN1 PA6   // LED connected to PA7

void setup() 
{
  Serial.begin(115200);
  pinMode(LED_PIN0, OUTPUT);   // Set LED pin as output
  pinMode(LED_PIN1, OUTPUT);   // Set LED pin as output
}

void loop() {
  Serial.print("Interrupt count: ");
  digitalWrite(LED_PIN0, HIGH);   // LED ON
  digitalWrite(LED_PIN1, HIGH);   // LED ON
  delay(100);                    // wait 500 ms
  digitalWrite(LED_PIN0, LOW);    // LED OFF
  digitalWrite(LED_PIN1, LOW);    // LED OFF
  delay(100);                    // wait 500 ms
}