// Constants for pin assignments
const int buttonPin = 2;  // Button connected to digital pin 2
const int segmentPins[] = {3, 4, 5, 6, 7, 8, 9};  // 7-segment display pins

// Digit patterns for 0-9 on a common cathode 7-segment display
const byte digitPatterns[10] = {
  B0111111, // 0
  B0000110, // 1
  B1011011, // 2
  B1001111, // 3
  B1100110, // 4
  B1101101, // 5
  B1111101, // 6
  B0000111, // 7
  B1111111, // 8
  B1101111  // 9
};

// Variables
int buttonState = 0;         // Variable to hold the button state
int lastButtonState = 0;     // Variable to hold the last button state
int counter = 0;             // Counter for button presses
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers

void setup() {
  // Initialize the button pin as an input
  pinMode(buttonPin, INPUT);
  // Initialize the segment pins as outputs
  for (int i = 0; i < 7; i++) {
    pinMode(segmentPins[i], OUTPUT);
  }
}

void loop() {
  // Read the state of the button
  int reading = digitalRead(buttonPin);

  // Check if the button state has changed
  if (reading != lastButtonState) {
    // Reset the debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // If the button state has changed
    if (reading != buttonState) {
      buttonState = reading;
      // Only increment the counter if the new button state is HIGH
      if (buttonState == HIGH) {
        counter++;
        // Reset counter if it goes beyond 9
        if (counter > 9) {
          counter = 0;
        }
        // Display the counter on the 7-segment display
        displayDigit(counter);
      }
    }
  }

  // Save the reading. Next time through the loop, it'll be the lastButtonState
  lastButtonState = reading;
}

void displayDigit(int digit) {
  // Get the digit pattern
  byte pattern = digitPatterns[digit];
  // Display the pattern on the 7-segment display
  for (int i = 0; i < 7; i++) {
    digitalWrite(segmentPins[i], bitRead(pattern, i));
  }
}