// -------- DIP SWITCH PINS (6 BIT) --------
const int dipPins[6] = {A0, A1, A2, A3, A4, A5};

// -------- SEGMENT PINS (a b c d e f g) --------
const int segPins[7] = {2, 3, 4, 5, 6, 7, 8};

// -------- DIGIT ENABLE PINS --------
const int digitPins[4] = {9, 10, 11, 12};

// Segment patterns for COMMON CATHODE
const byte numbers[10][7] = {
  {1,1,1,1,1,1,0}, // 0
  {0,1,1,0,0,0,0}, // 1
  {1,1,0,1,1,0,1}, // 2
  {1,1,1,1,0,0,1}, // 3
  {0,1,1,0,0,1,1}, // 4
  {1,0,1,1,0,1,1}, // 5
  {1,0,1,1,1,1,1}, // 6
  {1,1,1,0,0,0,0}, // 7
  {1,1,1,1,1,1,1}, // 8
  {1,1,1,1,0,1,1}  // 9
};

void setup() {
  // DIP switches
  for (int i = 0; i < 6; i++) {
    pinMode(dipPins[i], INPUT_PULLUP);
  }

  // Segment pins
  for (int i = 0; i < 7; i++) {
    pinMode(segPins[i], OUTPUT);
  }

  // Digit pins
  for (int i = 0; i < 4; i++) {
    pinMode(digitPins[i], OUTPUT);
  }
}

void loop() {
  int value = readDipSwitch();   // 0–63
  displayNumber(value);
}

// -------- READ 6-BIT DIP SWITCH --------
int readDipSwitch() {
  int val = 0;
  for (int i = 0; i < 6; i++) {
    if (digitalRead(dipPins[i]) == LOW) {
      val |= (1 << i);
    }
  }
  return val;
}

// -------- DISPLAY NUMBER (MULTIPLEXED) --------
void displayNumber(int num) {
  int digits[4];
  digits[0] = num / 1000;
  digits[1] = (num / 100) % 10;
  digits[2] = (num / 10) % 10;
  digits[3] = num % 10;

  for (int i = 0; i < 4; i++) {
    digitalWrite(digitPins[i], LOW);   // enable digit
    showDigit(digits[i]);
    delay(3);
    digitalWrite(digitPins[i], HIGH);  // disable digit
  }
}

// -------- SHOW ONE DIGIT --------
void showDigit(int num) {
  if (num > 9) num = 0;
  for (int i = 0; i < 7; i++) {
    digitalWrite(segPins[i], numbers[num][i]);
  }
}