Improving yet another nixie clock design

[Goldbrick_Gangboss]

Hello all! I wanted to start by thanking @pcbbc and @6v6gt for all the help provided in the past in getting my clock up and running.

I recently discovered Dalibor Farny who is making big brand new nixie tubes. If you'd like you can read about him here.
https://www.daliborfarny.com/

One of his customers made an awesome nixie clock called the covert Bombe. While watching the video I saw how they had implemented a gradual fade out of the previous nixie number segment, and a rapid roll of the number segment when transitioning to a new tens of seconds. The effects can be seen in the video below at the 1:05 segment. (I think I linked it so it would start there?)
https://youtu.be/S_mfCRBaQsM?t=65

I'd like to know if I can accomplish these effects using the SPI transfer that I have used in my sketch. Please see my full write up here.
https://www.hackster.io/Goldbrick_Gangboss/i-1-nixie-tube-clock-1st-prototype-c4902e

Here is my sketch for review. It's still a work in progress as I intend on adding a way to change the time along with a de-sputtering routine.

#include <Wire.h>
#include <RTClib.h>
#include <SPI.h>
#define NX 10
#define latchPin 10
#define blankPin 8
#define ledPin 12
int ledState = LOW;
int testpattern = 0;
/*#define burnPin 11
#define minutesPin 7
#define hoursPin 5 
int burnState = 1;
int minutesState = 1;
int hoursState = 1; */

RTC_DS1307 RTC;
DateTime now;
unsigned long previousMillis = 0;
const long interval = 1000;
unsigned long MinuteCount = 0;
unsigned long SecondCount = 0;


uint32_t Symbol[10]={0x1, 0x2, 0x4, 0x8 , 0x10, 0x20, 0x40, 0x80 , 0x100, 0x200};
/*Logic arrangement [ 0,   1,   2,   3 ,   4  ,  5  ,  6  ,  7  ,    8  ,   9  ]
                     LSB          << Shifts this way ------->
                                  >> Shifts this way <-------            MSB
                                     Personal Notes only */
void setup() {
  pinMode(ledPin,OUTPUT);
  pinMode(blankPin, OUTPUT);
  digitalWrite(blankPin, LOW);
  pinMode(latchPin, OUTPUT);
  /*pinMode(burnPin,INPUT);
  pinMode(minutesPin,INPUT);
  pinMode(hoursPin,INPUT); */
  Serial.begin(9600);
  RTC.begin();
  Wire.begin();
  SPI.begin();
  SPI.setDataMode(SPI_MODE2);
  SPI.setClockDivider(SPI_CLOCK_DIV4);
  //RTC.adjust(DateTime(F(__DATE__),F(__TIME__)));
  if (! RTC.isrunning()){
    Serial.println("RTC is NOT RUNNING!");
    RTC.adjust(DateTime(F(__DATE__),F(__TIME__))); 
  }  
  delay(1000);
  }

void loop() {
  digitalWrite(blankPin, HIGH);
  if (millis()-MinuteCount > 40000) {
    MinuteCount = millis();
    if (testpattern == 0) {
        testpattern = 1;
    } else if (testpattern == 1) {
      VegasProtocol();
      testpattern = 0;
    }
  } else if (millis()-SecondCount > 1000) {
    SecondCount = millis();
    GetTime();
    Timex();
  }
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval){
    previousMillis = currentMillis;
    if (ledState == LOW){
      ledState = HIGH;
    }else{
      ledState = LOW;
    }
    digitalWrite(ledPin, ledState);
  }
  /*burnState = digitalRead(burnPin);
  if (burnState == LOW){
    burnCycle();
  }
  minutesState = digitalRead(minutesPin);
  if (minutesState == LOW){
    setMinutes();
  }
  hoursState = digitalRead(hoursPin);
  if (hoursState == LOW){
    setHours();
  } */
  
  /*Uncomment to see serial monitor output of time
  Serial.print(now.hour(),DEC);
  Serial.print(':');
  Serial.print(now.minute(),DEC);
  Serial.println();
  delay(1500); */
  }

void VegasProtocol()
{
  uint16_t digitValue=0x200;
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    digitalWrite(latchPin,HIGH);
    digitValue=digitValue>>1;
    delay(100);}
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    digitalWrite(latchPin,HIGH);
    delay(100);}
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]<<1);
    SPI.transfer16(Symbol[i]<<2);
    SPI.transfer16(Symbol[i]<<3);
    digitalWrite(latchPin,HIGH);
    delay(150);}
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(Symbol[i]<<1);
    SPI.transfer16(Symbol[i]<<2);
    SPI.transfer16(Symbol[i]<<3);
    SPI.transfer16(Symbol[i]<<4);
    digitalWrite(latchPin,HIGH);
    delay(200);}
}
   
void Timex()
{
  digitalWrite(latchPin, LOW);                                      
  uint32_t Timemm;
  uint32_t Timehh;
  Timemm=now.minute();
  uint32_t Var32;                                  
  Var32=0;
  Var32|=(uint32_t)(Symbol[Timemm%10]<<16);//NX4 xx:x0
  Timemm=Timemm/10;  
  Var32|=(uint32_t)(Symbol[Timemm%10]);//NX3 xx:0x
  //Register 2 controlling NX3 and NX4    
  SPI.transfer(Var32>>24);
  SPI.transfer(Var32>>16);
  SPI.transfer(Var32>>8);
  SPI.transfer(Var32);
  Timehh=now.hour();
  Var32=0;
  Var32|=(uint32_t)(Symbol[Timehh%10]<<16);//NX2  x0:xx
  Timehh=Timehh/10;
  Var32|=(uint32_t)(Symbol[Timehh%10]);//NX1 0x:xx
  //Register 1 controlling NX1 and NX2
  SPI.transfer(Var32>>24);
  SPI.transfer(Var32>>16);
  SPI.transfer(Var32>>8);
  SPI.transfer(Var32);
  digitalWrite(latchPin, HIGH);  
}
void GetTime(){
  now = RTC.now();
}

/*void burnCycle(){
  {
  uint16_t digitValue=0x200;
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    SPI.transfer16(digitValue);
    digitalWrite(latchPin,HIGH);
    digitValue=digitValue>>1;
    delay(5000);}
  for (int i=0;i<NX; i++){
    digitalWrite(latchPin,LOW);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    SPI.transfer16(Symbol[i]);
    digitalWrite(latchPin,HIGH);
    delay(5000);}
  }
}

void setMinutes(){
}

void setHours(){
}
} */This text will be hidden

[6v6gt]

It looks a great project and I know these are a lot of fun to design and build. I currently have 3 Nixie clocks, one of which I published here, and the tubes for another 2 six digit clocks so I'll have something to do during the next lock down.

The tubes you have chosen (IN-1) tend, apparently, to have a relatively short lifetime because they are not doped with mercury. See: Nixie tubes (paragraph 4). If I had those, I'd probably also consider having a PIR sensor to switch the tubes off when the room is not occupied.

As for the fade in/out, I guess this could be achieved by varying the duty cycle on the cathodes of the two digits to be switched, over say a half second. You should be able to do that relatively easily, without having to deal with nuisance flicker, because your tubes are directly driven (not multiplexed).

[Goldbrick_Gangboss]

Perhaps I’ll consider the sensor in the redesign of the project. That’s a bummer on the tube life. It has been ticking away on my desktop since November. Only thing I’ve noticed is the sputtering on some digits. I’ll see what I can think upon for your suggestion. Thank you