//Tutorial : 
// constants won't change
const int buttonPin = 5; // pi pico connected to button's pin
const int LEDPin    = 6; // pi pico pin connected to LED's pin

// variables will change:
int ledState = LOW;     // the current state of LED
int lastButtonState;    // the previous state of button
int currentButtonState; // the current state of button

void setup() {
  Serial1.begin(9600);                // initialize serial
  pinMode(buttonPin, INPUT_PULLUP); // set pi pico pin to input pull-up mode
  pinMode(LEDPin, OUTPUT);          // set pi pico pin to output mode

  currentButtonState = digitalRead(buttonPin);
}

void loop() {
  lastButtonState    = currentButtonState;      // save the last state
  currentButtonState = digitalRead(buttonPin); // read new state

  if(lastButtonState == HIGH && currentButtonState == LOW) {
    Serial1.println("The button is pressed");

    // toggle state of LED
    ledState = !ledState;

    // control LED arccoding to the toggled state
    digitalWrite(LEDPin, ledState); 
  }
  delay(100);
}