// Define pins
const byte ButtonPin = 4;   // Push button attached to PB4 (with ground connection)
const byte LedPin1 = 0;     // LED1 attached to PB0
const byte LedPin2 = 1;     // LED2 attached to PB1

// Variables to store button state and debouncing
bool buttonState = HIGH;
bool lastButtonState = HIGH;
bool ledState = LOW;       // To keep track of which LED should turn on
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;  // Debounce time in milliseconds

void setup() {
  // Set pin modes
  pinMode(ButtonPin, INPUT_PULLUP);  // Use internal pull-up resistor
  pinMode(LedPin1, OUTPUT);
  pinMode(LedPin2, OUTPUT);

  // Start with both LEDs off
  digitalWrite(LedPin1, LOW);
  digitalWrite(LedPin2, LOW);
}

void loop() {
  // Read the button state
  bool reading = digitalRead(ButtonPin);

  // Check for button press with debounce
  if (reading != lastButtonState) {
    lastDebounceTime = millis(); // Reset the debouncing timer
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // Only act if the button state has changed
    if (reading != buttonState) {
      buttonState = reading;

      // If the button is pressed (LOW)
      if (buttonState == LOW) {
        // Toggle LED state
        ledState = !ledState;
        
        // Turn on the LEDs based on the current state
        if (ledState) {
          digitalWrite(LedPin1, HIGH);  // Turn on LED1
          digitalWrite(LedPin2, LOW);   // Turn off LED2
        } else {
          digitalWrite(LedPin1, LOW);   // Turn off LED1
          digitalWrite(LedPin2, HIGH);  // Turn on LED2
        }
      } else {
        // If button is released, turn off both LEDs
        digitalWrite(LedPin1, LOW);
        digitalWrite(LedPin2, LOW);
      }
    }
  }

  // Save the last button state
  lastButtonState = reading;
}