/*
  Showing number 0-9 on a Common Anode 7-segment LED display
  Displays the numbers 0-9 on the display, with one second inbetween.
   A
F     B
   G
E     C
   D
*/

int pinA = 11;
int pinB = 7;
int pinC = 4;
int pinD = 2;
int pinE = 1;
int pinF = 10;
int pinG = 5;
int dp = 3;
int D1 = 12;
int D2 = 9;
int D3 = 8;
int D4 = 6;

void all_low() {
  digitalWrite(pinA, LOW);
  digitalWrite(pinB, LOW);
  digitalWrite(pinC, LOW);
  digitalWrite(pinD, LOW);
  digitalWrite(pinE, LOW);
  digitalWrite(pinF, LOW);
  digitalWrite(pinG, LOW);
  digitalWrite(dp, HIGH);
}

void digit0() {
  digitalWrite(pinG, HIGH);
}

void digit1() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
}

void digit2() {
  digitalWrite(pinC, HIGH);
  digitalWrite(pinF, HIGH);
}

void digit3() {
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
}

void digit4() {
  digitalWrite(pinA, HIGH);
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
}

void digit5() {
  digitalWrite(pinB, HIGH);
  digitalWrite(pinE, HIGH);
}

void digit6() {
  digitalWrite(pinB, HIGH);
}

void digit7() {
  digitalWrite(pinD, HIGH);
  digitalWrite(pinE, HIGH);
  digitalWrite(pinF, HIGH);
  digitalWrite(pinG, HIGH);
}

void digit8() {
  all_low();
}

void digit9() {
  digitalWrite(pinE, HIGH);
}

void setup() {
  pinMode(pinA, OUTPUT);
  pinMode(pinB, OUTPUT);
  pinMode(pinC, OUTPUT);
  pinMode(pinD, OUTPUT);
  pinMode(pinE, OUTPUT);
  pinMode(pinF, OUTPUT);
  pinMode(pinG, OUTPUT);
  pinMode(dp, OUTPUT);
  pinMode(D1, OUTPUT);
  pinMode(D2, OUTPUT);
  pinMode(D3, OUTPUT);
  pinMode(D4, OUTPUT);
}

void showDigit(int p, int n) {
  digitalWrite(D1, LOW);
  digitalWrite(D2, LOW);
  digitalWrite(D3, LOW);
  digitalWrite(D4, LOW);
  if (p == 0) digitalWrite(D1, HIGH);
  else if (p == 1) digitalWrite(D2, HIGH);
  else if (p == 2) digitalWrite(D3, HIGH);
  else if (p == 3) digitalWrite(D4, HIGH);
  all_low();
  switch (n){
    case 0: digit0(); break;
    case 1: digit1(); break;
    case 2: digit2(); break;
    case 3: digit3(); break;
    case 4: digit4(); break;
    case 5: digit5(); break;
    case 6: digit6(); break;
    case 7: digit7(); break;
    case 8: digit8(); break;
    case 9: digit9(); break;
  }
  delay(1);
}

void printNumber(int n) {
  int x = floor(n / 1000);
  showDigit(0, x);  n = n % 1000;  x = floor(n / 100);
  showDigit(1, x);  n = n % 100;   x = floor(n / 10);
  showDigit(2, x);
  showDigit(3, n % 10);
}

int n=0;
void loop() {
  int i;
  // n=random(1000,10000);
  for(i=0;i<20;i++)
    printNumber(n);
  n++;
  if(n>9999) n=0;
}