void setup() {
    pinMode(PA0, OUTPUT); // Letter 1
    pinMode(PA1, OUTPUT); // A
    pinMode(PA2, OUTPUT); // F
    pinMode(PA3, OUTPUT); // E
    pinMode(PA4, OUTPUT); // D
    pinMode(PA5, OUTPUT); // C
    pinMode(PA6, OUTPUT); // B
    pinMode(PA7, OUTPUT); // Letter 2

    // Start with the "F"
    digitalWrite(PA0, HIGH);
    digitalWrite(PA1, LOW);
    digitalWrite(PA2, LOW);
    digitalWrite(PA3, LOW);
    digitalWrite(PA4, LOW);
    digitalWrite(PA5, LOW);
    digitalWrite(PA6, LOW);
    digitalWrite(PA7, LOW);

    // Print the second letter
    delay(100);
    digitalWrite();
}

void loop() {
  /*
    digitalWrite(PC13, HIGH);
    digitalWrite(PB3, LOW);
    delay(500);
    digitalWrite(PC13,LOW);
    digitalWrite(PB3, HIGH);
    delay(500);
    */
  }