Messing with a Common Anode Seven Segment Display on Arduino Uno

count_forever.c

#define _A 7
#define _B 6
#define _C 4
#define _D 2
#define _E 1
#define _F 9
#define _G 10
#define _DP 5
#define LED_OFF 1
#define LED_ON 0
#define STEP_DELAY 100
#define PIN_COUNT 8
#define ELEMENT_COUNT 10
#define MAX_PINS_PER_ELEMENT 7

int iterator = 0;

unsigned int pins[PIN_COUNT] = {_A, _B, _C, _D, _E, _F, _G, _DP};

unsigned int pin_combinations[ELEMENT_COUNT][MAX_PINS_PER_ELEMENT] = { 
  {_A, _B, _C, _D, _E, _F},
  {_B, _C},
  {_A, _B, _G, _E, _D},
  {_A, _B, _G, _C, _D},
  {_F, _B, _G, _C},
  {_A, _F, _G, _C, _D},
  {_A, _F, _G, _C, _D, _E},
  {_A, _B, _C},
  {_A, _B, _C, _D, _E, _F, _G},
  {_A, _B, _C, _D, _F, _G}
};

void clear_leds() {
  for (int i = 0; i < PIN_COUNT; i++) {
    digitalWrite(pins[i], LED_OFF);
  }
}

void setup() {
  for (int i = 0; i < PIN_COUNT; i++) {
    pinMode(pins[i], OUTPUT);
  }
}

void loop() {
  clear_leds();
  digitalWrite(_DP, !(iterator == 0));
  int combination_size = sizeof(pin_combinations[iterator]) / sizeof(pin_combinations[iterator][0]);
  
  for (int i = 0; i < combination_size; i++) {
    digitalWrite(pin_combinations[iterator][i], LED_ON);
  }
  
  iterator = (iterator + 1) % ELEMENT_COUNT;
  delay(STEP_DELAY);
}