STM32 read btns & pots

//Buttons pin number array
byte Btns[16] = {13,12,14,27,26,25,33,32,15,4,16,17,18,19,22,23};

//VarPots pin number array
byte Pots[4] = {35, 34, 39, 36};

void setup()
{
  Serial.begin (115200);

  for (int i = 0; i<16; i++)
  {
    pinMode(Btns[i], INPUT_PULLUP);
  }

}

void loop()
{
  //VarPots(); //uncomment this line to test the potentiometers
  //Buttons(); //uncomment this line to test the buttons
}

void Buttons ()
{
  for (int i = 0; i<16; i++)
  {
    if (digitalRead(Btns[i]) == LOW)
    {
      Serial.print ("Button "); Serial.print (i+1); Serial.println (" ON");
    }
  }
}

void VarPots ()
{
  for (int i = 0; i<4; i++)
  {
      Serial.print ("Pot "); Serial.print (i+1);
      Serial.print (" / Value: "); Serial.print(analogRead(Pots[i]));
      Serial.print (" | ");
  }

  Serial.println();
}