Cyber dice: seven-segment on pins 2 to 8, button on 9, on an Arduino Uno

// Cyber dice: hold the button to roll, let go to see the number.
//
//   seven-segment a..g -> pins 2..8 (one 220 ohm on the common leg to GND)
//   button: one side -> 5V, the other -> pin 9, and 10k from pin 9 to GND
//
// Each digit is a pattern of seven segments, kept as one byte with a bit per
// segment: bit 0 is a, bit 6 is g. show() lights the segments whose bits are
// set. While the button is held the digit flickers through 1 to 6; on release
// random() picks the roll.

const int SEGMENT_PINS[7] = {2, 3, 4, 5, 6, 7, 8};
const int BUTTON = 9;

const byte DIGITS[7] = {
  0b0111111,  // 0
  0b0000110,  // 1
  0b1011011,  // 2
  0b1001111,  // 3
  0b1100110,  // 4
  0b1101101,  // 5
  0b1111101,  // 6
};

void show(int n) {
  for (int s = 0; s < 7; s++) digitalWrite(SEGMENT_PINS[s], (DIGITS[n] >> s) & 1);
}

void setup() {
  for (int s = 0; s < 7; s++) pinMode(SEGMENT_PINS[s], OUTPUT);
  pinMode(BUTTON, INPUT);
  randomSeed(analogRead(A0));
  show(0);
  Serial.begin(9600);
  Serial.println("Mokxi Uno: hold the button on pin 9 to roll the dice");
}

void loop() {
  if (digitalRead(BUTTON) == HIGH) {
    int spin = 1;
    while (digitalRead(BUTTON) == HIGH) {
      show(spin);
      spin = spin % 6 + 1;
      delay(60);
    }
    int roll = random(1, 7);
    show(roll);
    Serial.print("you rolled ");
    Serial.println(roll);
  }
}