#include "stm32c0xx.h"

#define A 8
#define B 9
#define C 7
#define D 6
#define E 5
#define F 3
#define G 15

int tab[5][7] =
{
    // a b c d e f g
    {0, 0, 0, 1, 0, 0, 0}, // A
    {0, 1, 1, 0, 0, 0, 0}, // E
    {1, 0, 0, 1, 1, 1, 1}, // I
    {0, 0, 0, 0, 0, 0, 1}, // O
    {1, 0, 0, 0, 0, 0, 1}  // U
};

void delay_ms(volatile uint32_t ms)
{
    for (volatile uint32_t j = 0; j < ms * 800; j++);
}

void display_number(int num)
{
    if (tab[num][0]) GPIOA->BSRR = (1U << A);
    else              GPIOA->BRR  = (1U << A);

    if (tab[num][1]) GPIOA->BSRR = (1U << B);
    else              GPIOA->BRR  = (1U << B);

    if (tab[num][2]) GPIOA->BSRR = (1U << C);
    else              GPIOA->BRR  = (1U << C);

    if (tab[num][3]) GPIOA->BSRR = (1U << D);
    else              GPIOA->BRR  = (1U << D);

    if (tab[num][4]) GPIOA->BSRR = (1U << E);
    else              GPIOA->BRR  = (1U << E);

    if (tab[num][5]) GPIOA->BSRR = (1U << F);
    else              GPIOA->BRR  = (1U << F);

    if (tab[num][6]) GPIOA->BSRR = (1U << G);
    else              GPIOA->BRR  = (1U << G);
}

int main(void)
{
    /* Enable clock GPIOA */
    RCC->IOPENR |= RCC_IOPENR_GPIOAEN;

    /* Set PA3, PA5, PA6, PA7, PA8, PA9, PA15 sebagai output */
    GPIOA->MODER &= ~((3U << (2 * A)) | (3U << (2 * B)) | (3U << (2 * C)) |
                      (3U << (2 * D)) | (3U << (2 * E)) | (3U << (2 * F)) |
                      (3U << (2 * G)));

    GPIOA->MODER |=  ((1U << (2 * A)) | (1U << (2 * B)) | (1U << (2 * C)) |
                      (1U << (2 * D)) | (1U << (2 * E)) | (1U << (2 * F)) |
                      (1U << (2 * G)));

    int i = 0;

    while (1)
    {
        display_number(i);
        delay_ms(1000);

        if (i == 4)
            i = 0;
        else
            i++;
    }
}