If we want to easily track how a button acts, serial communication is the best and simplest way. All we need to do is to read the status of the button and print it to the serial connection.

Testing whether a button is working can be solved by using an LED. However, if we need to check two buttons or better understand what's happening when the button is pressed, serial communication is much safer and may even be simpler.

int buttonPin = 2;

void setup() {
  // Define pin #2 as input
  pinMode(buttonPin, INPUT_PULLUP);

  // Establish the...