Side Push Button

const int buttonPin = A0; // Button connected to digital pin 2

void setup() {
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as input with internal pull-up resistor
  Serial.begin(9600);              // Initialize Serial Monitor at 9600 baud
}

void loop() {
  int buttonState = digitalRead(buttonPin); // Read the button state
  if (buttonState == LOW) {                // Button pressed (LOW because of pull-up)
    Serial.println("PRESSED");
  } else {                                 // Button released
    Serial.println("RELEASED");
  }
  delay(80); // Small delay to avoid flooding the Serial Monitor
}