Binary Clock (Another one) using RTC.

This is binary clock that I created around Mini Pro and RTC 3231. First 2 columns(from the left)-hours, next 2 minutes, and the last 2 temperature. RTC3231 has built in Temperature sensor.

I use multiplexing for displaying as there are not enough IO pins for connecting. The projects works flawles. No flickering either.

I will appreciate any improvement suggestions as I am not a programmer and not sure if things done this way.

/*Binaryclock using multiplexing by systemGamer Mannheim 20200522
   V3.0 This version also incorporates room temperature reading instead of seconds section

              +
    o   o   o 2
    o o o o o 3
  o o o o o o 5
  o o o o o o 4
  6 7 8 9 10 11 -
*/
#include "RTClib.h"
RTC_DS3231 rtc;

void setup() {
#ifndef ESP8266
  while (!Serial); // for Leonardo/Micro/Zero
#endif
  Serial.begin(9600);
  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  for (int ttl = 2; ttl < 12; ttl++) {
    pinMode(ttl, OUTPUT);
  }
}
int row[4] = {5, 4, 3, 2};
int column[6] = {6, 7, 8, 9, 10, 11};
byte rowState =    B00000000;
byte columnState = B00000001;//scan throgh columns with this one
byte section[6];
int a = 0;
void loop() {
  updateSection(a);
  updateLeds();
  a++;
  columnState = columnState << 1;
  if (columnState == 64) {
    columnState = 1;
  }
  if (a == 6) {
    a = 0;
  }

}
void updateSection(int a) {
  DateTime now = rtc.now();

  int hour1 = now.hour();
  section[0] = (hour1 / 10);
  section[1] = (hour1 % 10);
  int minute1 = now.minute();
  section[2] = (minute1 / 10);
  section[3] = (minute1 % 10);
  int temperature = rtc.getTemperature();
  section[4] = (temperature / 10);
  section[5] = (temperature % 10);
  rowState = section[a];

}

void updateLeds() {
  for (int ttl = 0; ttl < 4; ttl++) { // set first 4 bits of rowState to rows
    digitalWrite(row[ttl], bitRead(rowState, ttl));
  }
  for (int ttl = 0; ttl < 6; ttl++) { // set first 6 bits of rowState to rows
    digitalWrite(column[ttl], bitRead(~columnState, ttl));
  }
}