Button Test

ButtonTest.ino starts the USB Serial Port, then inits the button pins as inputs with pullup. The state of each pin is printed every 100ms. A button is pressed when digitalRead() returns 0. Open the Arduino Serial Monitor to see the output after uploading the sketch.

ButtonTest.ino

#define BTN_UP 14
#define BTN_DOWN 15
#define BTN_LEFT 16
#define BTN_RIGHT 17
#define BTN_A 18
#define BTN_B 21

void setup() {
  Serial.begin(115200);
  while(!Serial);
  Serial.println("STARTED");

  pinMode(BTN_UP, INPUT_PULLUP);
  pinMode(BTN_DOWN, INPUT_PULLUP);
  pinMode(BTN_LEFT, INPUT_PULLUP);
  pinMode(BTN_RIGHT, INPUT_PULLUP);
  pinMode(BTN_A, INPUT_PULLUP);
  pinMode(BTN_B, INPUT_PULLUP);
}

void loop() {
  Serial.printf("UP %d | DOWN %d | LEFT %d | RIGHT %d | A %d | B %d \n",
    digitalRead(BTN_UP),
    digitalRead(BTN_DOWN),
    digitalRead(BTN_LEFT),
    digitalRead(BTN_RIGHT),
    digitalRead(BTN_A),
    digitalRead(BTN_B)
  );
  delay(100);
}