7segment-led

const int a = 11;
const int b = 7;
const int c = 4;
const int d = 2;
const int e = 1;
const int f = 10;
const int g = 5;
const int p = 3;

const int d1 = 12;
const int d2 = 9;
const int d3 = 8;
const int d4 = 6;

const boolean isAnode = true;

void setup() {
  for (int i = 1; i <= 12; i = i + 1) {
    pinMode(i, OUTPUT);
  }
}

void on(int pin) {
  if (isAnode) {
   digitalWrite(pin, HIGH);
  } else {
   digitalWrite(pin, LOW);
  }
}

void off(int pin) {
  if (isAnode) {
   digitalWrite(pin, LOW);
  } else {
   digitalWrite(pin, HIGH);
  }
}

void reset(int digiPin) {
  off(d1);
  off(d2);
  off(d3);
  off(d4);
  
  on(digiPin);

  on(a);
  on(b);
  on(c);
  on(d);
  on(e);
  on(f);
  on(g);
  on(p);
}

void loop() {
  reset(d1);
  off(a);
  delay(4);
  reset(d2);
  off(b);
  delay(4);
  
  reset(d3);
  off(c);
  delay(4);
  
  reset(d4);
  off(d);
  delay(4);
}