const int BTN_A = 12;   // tu cable
const int BTN_B = 14;   // tu cable

void setup() {
  Serial.begin(115200);
  pinMode(BTN_A, INPUT_PULLUP);
  pinMode(BTN_B, INPUT_PULLUP);
}

void loop() {
  int a = digitalRead(BTN_A);
  int b = digitalRead(BTN_B);
  Serial.printf("A=%d  B=%d\n", a, b);
  delay(300);
}