Seven-segment digit on pins 4 to 11, on an Arduino Uno

// A seven-segment display driven straight from eight pins: 0 to 9.
//
//   segment a -> pin 7    b -> pin 6    c -> pin 5    d -> pin 11
//   segment e -> pin 10   f -> pin 8    g -> pin 9    dp -> pin 4
//   each through its own 220 ohm; the common cathode -> GND
//
// Each segment is an LED. A digit is a pattern of lit segments, kept here as
// one byte per digit with segment a in the lowest bit. The sketch walks the
// seven bits and sets each segment's pin from its bit.

//                         gfedcba
const byte DIGITS[10] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F};
const int SEGMENT_PINS[7] = {7, 6, 5, 11, 10, 8, 9};  // a to g
const int DOT_PIN = 4;

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

void setup() {
  for (int s = 0; s < 7; s++) pinMode(SEGMENT_PINS[s], OUTPUT);
  pinMode(DOT_PIN, OUTPUT);
  Serial.begin(9600);
  Serial.println("Mokxi Uno: seven segments on pins 4 to 11");
}

void loop() {
  for (int n = 0; n <= 9; n++) {
    show(n);
    digitalWrite(DOT_PIN, n % 2);
    Serial.println(n);
    delay(1000);
  }
}