• Uses two cores of the ESP32
• Directly access's GPIO pins using registers
• Utilities ESP32's touch sensors
• Limited comments :-)

TaskHandle_t Task1;
TaskHandle_t Task2;
 #include <Wire.h>
 #include <DS3231.h>
 #include <analogWrite.h>
 #define PARALLEL_0  14  //12 create a parallel bus using GPIO 12,13,14,15 i.e. consecutive pins
 DS3231 Clock;
 byte Year;byte Month;byte Date;byte DoW;byte Hour;byte Minute;byte Second;byte Neon;bool Century=false;bool h12;bool PM;
int pausey ; int copperbuttons ; int oldsecond;int countdown;
int tube=0;int digit=0;int tubebar[4];
byte touch1;byte touch2;byte touch3;byte touch4;byte touch5;byte touch6;byte touch7;byte touch8;
int settimeloop;
void setup() {
 ledcSetup(2,1E5,12);
  
  for (int i = 0; i < 3; i++) {
    pinMode(PARALLEL_0 + i, INPUT); //setp up as inputs ....however can be used as outputs ...see below.
  }
  parallel_set_outputs();
  
   //create a task that will be executed in the Task1code() function, with priority 1 and executed on core 0
  xTaskCreatePinnedToCore(
                    Task1code,   /* Task function. */
                    "Task1",     /* name of task. */
                    10000,       /* Stack size of task */
                    NULL,        /* parameter of the task */
                    1,           /* priority of the task */
                    &Task1,      /* Task handle to keep track of created task */
                    0);          /* pin task to core 0 */                  

  //create a task that will be executed in the Task2code() function, with priority 1 and executed on core 1
  xTaskCreatePinnedToCore(
                    Task2code,   /* Task function. */
                    "Task2",     /* name of task. */
                    10000,       /* Stack size of task */
                    NULL,        /* parameter of the task */
                    1,           /* priority of the task */
                    &Task2,      /* Task handle to keep track of created task */
                    1);          /* pin task to core 1 */

    Serial.begin(57600);
    Wire.begin();
 
   pinMode(14, OUTPUT);  pinMode(15, OUTPUT); pinMode(16, OUTPUT);  pinMode(17, OUTPUT); // bcd
  pinMode(18, OUTPUT);  pinMode(19, OUTPUT);  pinMode(25, OUTPUT);  pinMode(26, OUTPUT);  // Nixie tube

  pinMode(32, OUTPUT); pinMode(33, OUTPUT);// seconds neon
 }
void loop() { 
      touch5= touchRead(4); delay(80); touch6=touchRead(4);  delay(80); 
      touch7= touchRead(27); delay(80); touch8=touchRead(27);  delay(80);
      touch1= touchRead(12); delay(80); touch2=touchRead(12);  delay(80); 
      touch3= touchRead(13); delay(80); touch4=touchRead(13); delay(80);

     copperbuttons=((touch5<40)&(touch6<40))*8 + ((touch7<40)&(touch8<40))*4 + ((touch3<40)&(touch4<40))*2 + ((touch1<40)&(touch2<40))*1 ;
switch (copperbuttons){
     case 3: Serial.println("Right pair");delay(100); break ;
     case 6: Serial.println("Middle Pair");delay(100); alarm();break ;
     case 12: Serial.println("Left pair");delay(100); break ;
     case 15: Serial.println("Set Time");delay(100); countdown=10;oldsecond=Clock.getSecond(), DEC;set_time(); break ;
}

}
void tubedigit (int i)
{
 Hour=Clock.getHour(h12, PM), DEC;
 Minute=Clock.getMinute(), DEC;
 Second=Clock.getSecond(), DEC;
 Neon=Second>>1;Neon=Neon<<1;

 tubebar[0]=Minute-((Minute/10)*10);
 tubebar[1]=Minute/10;
 tubebar[2]=Hour-((Hour/10)*10);
 tubebar[3]=Hour/10;
  for ( i=0; i <=3; i++){
parallel_write( tubebar[i]); //output gpio 12,13,14,15 as a bitwise operation

int j=i;
if (j==0) {digitalWrite(18, LOW); digitalWrite(19, LOW);  digitalWrite(25, LOW); digitalWrite(26, HIGH);}
if (j==1) {digitalWrite(18, LOW); digitalWrite(19, LOW);  digitalWrite(25, HIGH); digitalWrite(26, LOW);}
if (j==2) {digitalWrite(18, LOW); digitalWrite(19, HIGH);  digitalWrite(25, LOW); digitalWrite(26, LOW);}
if (j==3) {digitalWrite(18, HIGH); digitalWrite(19, LOW);  digitalWrite(25, LOW); digitalWrite(26, LOW);}
delay(5);
}
}

//Task1code: Call tubedigit update
void Task1code( void * pvParameters ){

  for(;;){
   tubedigit(0);
  } 
}

//Task2code: blink Neon seconds indicator
void Task2code( void * pvParameters ){
  
 for(;;){
  if (Second==Neon) {analogWrite(32,20);} else {analogWrite(32, 0);} // dimmable pwm
}
}

void parallel_set_outputs(void) {
  REG_WRITE(GPIO_ENABLE_W1TS_REG, 0xFF << PARALLEL_0);
}
void parallel_write(uint8_t value) {
  uint32_t output =
    (REG_READ(GPIO_OUT_REG) & ~(0xFF << PARALLEL_0)) | (((uint32_t)value) << PARALLEL_0);

  REG_WRITE(GPIO_OUT_REG, output);
}
void set_time (){
uint32_t period = 1 * 20000L;    

for( uint32_t tStart = millis();  (millis()-tStart) < period;  ){
    touch5= touchRead(4); delay(80); touch6=touchRead(4);  delay(80); 
    touch7= touchRead(27); delay(80); touch8=touchRead(27);  delay(80);
    touch1= touchRead(12); delay(80); touch2=touchRead(12);  delay(80); 
    touch3= touchRead(13); delay(80); touch4=touchRead(13); delay(80);

    copperbuttons=((touch5<50)&(touch6<50))*8 + ((touch7<50)&(touch8<50))*4 + ((touch3<50)&(touch4<50))*2 + ((touch1<50)&(touch2<50))*1 ;
switch (copperbuttons){
     case 1: Minute++;Clock.setMinute(Minute); delay(50);  break ;
     case 2: Minute--;Clock.setMinute(Minute); delay(50);  break ;
     case 4: Hour++;Clock.setHour(Hour); delay(50);  break ;
     case 8: Hour--;Clock.setHour(Hour); delay(50);  break ;  
 }
delay(100);
}

}
void minute10 (){
uint32_t period2 = 1 * 60000L;    
for( uint32_t tStart2 = millis();  (millis()-tStart2) < period2;  ){
}
}
void alarm(){
  ledcAttachPin(33, 2);
   for (int ii=000; ii <= 5000; ii=ii+66){
       ledcWriteTone(2,ii);
      delay(8);
   }
  for (int ii=5000; ii >= 000; ii=ii-33){
       ledcWriteTone(2,ii);
      delay(8);
     }
     ledcDetachPin(33);
}