Arduino HV5530 + DS3231

/*
Nixie Clock Code by Andrei Aldea

Adapted for use with HV5530 Nixie Driver boards  by Johnny Izzard
And the Sodaq_DS3231 library by Sodaq Moja
*/

#include <SPI.h>
#include <Wire.h>
#include "Sodaq_DS3231.h"

char weekDay[][4] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };

#define LD 10
#define CLK 13
#define SDO 11
#define PWM 9

uint32_t old_ts;


#define tube_off 10
#define ind_off 3

uint16_t decimal_lookup[11] = {0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080, 0x0100, 0x0200, 0x0000}; // decimal_lookup[0]...decimal_lookup[9] outputs corresponding nixie number. decimal_lookup[10] is off.
uint8_t ind_lookup[4] = {0x01, 0x02, 0x03, 0x00}; // ind_lookup[0] is top indicator, ind_lookup[1] is bottom indicator, ind_lookup[2] is both, ind_lookup[3] is off.

uint32_t data1 = 0; // Used to store data to be shifted
uint32_t data2 = 0;
uint32_t data3 = 0;
uint32_t data4 = 0;

uint8_t  tube1 = 0; // Value to display on the corresponding tube.
uint8_t  tube2 = 0;
uint8_t  tube3 = 0;
uint8_t  tube4 = 0;
uint8_t  tube5 = 0;
uint8_t  tube6 = 0;
uint8_t  tube7 = 0;
uint8_t  tube8 = 0;

uint8_t indicator1 = 0; // Value to display on the corresponding indicator.
uint8_t indicator2 = 0;
uint8_t indicator3 = 0;
uint8_t indicator4 = 0;


void setup() {
  Serial.begin(57600);
  Wire.begin();
  rtc.begin();

  pinMode(LD, OUTPUT); // LD is pin 10 (active high)
  pinMode(CLK, OUTPUT); // CLK is pin 13
  pinMode(SDO, OUTPUT); // SDO is pin 11
  pinMode(PWM, OUTPUT); // PWM (Blank) is pin 9 (active low)
  digitalWrite(LD, LOW);
  digitalWrite(CLK, LOW);
  digitalWrite(SDO, LOW);
  digitalWrite(PWM, HIGH);
  SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE1));

  /* Reset Values/Blank The Display */
  tube1 = tube_off;
  tube2 = tube_off;
  tube3 = tube_off;
  tube4 = tube_off;
  tube5 = tube_off;
  tube6 = tube_off;
  tube7 = tube_off;
  tube8 = tube_off;
  indicator1 = ind_off;
  indicator2 = ind_off;
  indicator3 = ind_off;
  indicator4 = ind_off;
  update_disp();
}

void loop() {

  DateTime now = rtc.now(); //get the current date-time
  uint32_t ts = now.getEpoch();
  analogWrite(PWM, 150); //Set Brightness
  if (old_ts == 0 || old_ts != ts) {
    old_ts = ts;
    
    indicator1 = 2; // Both indicators on
    indicator2 = 2;
    indicator3 = 2;
    indicator4 = ind_off;
    tube8 = now.hour()/10;
    tube7 = now.hour()%10;
    tube6 = now.minute()/10;
    tube5 = now.minute()%10;
    tube4 = now.second()/10;
    tube3 = now.second()%10;
    tube2 = 2;
    tube1 = 2;
    update_disp();
    /*for(int i=0; i<=99; i++)
    {
    tube2 = i/10;
    tube1 = i%10;
    delay(10);
    update_disp();
    }
  }*/
  }
  //delay(500);
}

void update_disp(void) {
  data1 = 0x00000000;
  data1 |= ((uint32_t (decimal_lookup[tube1])) & 0x000003FF);
  data1 |= ((uint32_t (decimal_lookup[tube2]) << 10) & 0x000FFC00);
  data1 |= ((uint32_t (ind_lookup[indicator1]) << 20) & 0x00300000);

  data2 = 0x00000000;
  data2 |= ((uint32_t (decimal_lookup[tube3])) & 0x000003FF);
  data2 |= ((uint32_t (decimal_lookup[tube4]) << 10) & 0x000FFC00);
  data2 |= ((uint32_t (ind_lookup[indicator2]) << 20) & 0x00300000);

  data3 = 0x00000000;
  data3 |= ((uint32_t (decimal_lookup[tube5])) & 0x000003FF);
  data3 |= ((uint32_t (decimal_lookup[tube6]) << 10) & 0x000FFC00);
  data3 |= ((uint32_t (ind_lookup[indicator3]) << 20) & 0x00300000);

  data4 = 0x00000000;
  data4 |= ((uint32_t (decimal_lookup[tube7])) & 0x000003FF);
  data4 |= ((uint32_t (decimal_lookup[tube8]) << 10) & 0x000FFC00);
  data4 |= ((uint32_t (ind_lookup[indicator4]) << 20) & 0x00300000);

  digitalWrite(LD, HIGH);
  SPI.transfer(data1 >> 24);
  SPI.transfer(data1 >> 16);
  SPI.transfer(data1 >> 8);
  SPI.transfer(data1);
  digitalWrite(LD, LOW);
  digitalWrite(LD, HIGH);

  digitalWrite(LD, HIGH);
  SPI.transfer(data2 >> 24);
  SPI.transfer(data2 >> 16);
  SPI.transfer(data2 >> 8);
  SPI.transfer(data2);
  digitalWrite(LD, LOW);
  digitalWrite(LD, HIGH);

  digitalWrite(LD, HIGH);
  SPI.transfer(data3 >> 24);
  SPI.transfer(data3 >> 16);
  SPI.transfer(data3 >> 8);
  SPI.transfer(data3);
  digitalWrite(LD, LOW);
  digitalWrite(LD, HIGH);

  digitalWrite(LD, HIGH);
  SPI.transfer(data4 >> 24);
  SPI.transfer(data4 >> 16);
  SPI.transfer(data4 >> 8);
  SPI.transfer(data4);
  digitalWrite(LD, LOW);
  digitalWrite(LD, HIGH);
}