uint8_t lastkey = 0;

static char* _qwertzuiop = "qwertyuiop";
static char* _asdfghjkl = "asdfghjkl";
static char* _yxcvbnm = "zxcvbnm";
static char* _num = "123456789";

static char* _caps_qwertzuiop = "QWERTYUIOP";
static char* _caps_asdfghjkl = "ASDFGHJKL";
static char* _caps_yxcvbnm = "ZXCVBNM";

uint8_t keyboard_to_ascii(uint8_t key) {
    if(key == ENTER_PRESSED) return '\n';
    if(key == SPACE_PRESSED) return ' ';
    if(key == ENTER_PRESSED) return '\r';
    if(key == POINT_RELEASED) return '.';
    if(key == SLASH_RELEASED) return '/';
    if(key == ZERO_PRESSED) return '0';
    if(key >= ONE_PRESSED && key <= NINE_PRESSED)
        return _num[key - ONE_PRESSED];
    if(key >= Q_PRESSED && key <= ENTER_PRESSED)
    {
        if (lastkey == LSHIFT_PRESSED || lastkey == RSHIFT_PRESSED) {
            return _caps_qwertzuiop[key - Q_PRESSED];
        } else {
            return _qwertzuiop[key - Q_PRESSED];
        }
    } else if(key >= A_PRESSED && key <= L_PRESSED)
    {
        if (lastkey == LSHIFT_PRESSED || lastkey == RSHIFT_PRESSED) {
            return _caps_asdfghjkl[key - A_PRESSED];
        } else {
            return _asdfghjkl[key - A_PRESSED];
        }
    } else if(key >= Z_PRESSED && key <= M_PRESSED)
    {
        if (lastkey == LSHIFT_PRESSED || lastkey == RSHIFT_PRESSED) {
            return _caps_yxcvbnm[key - Z_PRESSED];
        } else {
            return _yxcvbnm[key - Z_PRESSED];
        }
    }

    lastkey = key;

    return 0;
}