06I-ONE-Nixie-Clock---Classic-Nixie-Clock-PWM-Fade-In-Out-PWM-Upgrade.ino

// ONE Nixie Clock by Marcin Saj https://nixietester.com
// https://github.com/marcinsaj/ONE-Nixie-Clock
//
// Classic Nixie Clock with PWM fade in/out effect Upgrade
// This example demonstrates how to set 75Hz PWM frequency 
// and how to set new time, display (time) digits or symbols 
// fade in/out effect and fade in/out backlight color effect.
//
// Hardware:
// ONE Nixie Clock Arduino Shield - https://nixietester.com/project/one-nixie-clock
// Arduino Nano 33 IoT - https://store.arduino.cc/arduino-nano-33-iot
//
// NOTE: For Arduino Nano 33 IoT use 3.3V power settings on the clock motherboard (VCC jumper)
//
// Nixie Tube Socket - https://bit.ly/nixie-socket & https://bit.ly/NixieSocket-Project
// Nixie Power Supply module and RTC DS3231 module
// Nixie Clock require 12V, 1.5A power supply
// Schematic ONE Nixie Clock - http://bit.ly/ONE-Nixie-Clock-Schematic
// Schematic Nixie Power Supply Module - http://bit.ly/ONE-Nixie-Clock-NPS-Module
// DS3231 RTC datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf

#include <Adafruit_NeoPixel.h>
// https://github.com/adafruit/Adafruit_NeoPixel
// https://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library-use

#include <RTClib.h>
// https://github.com/adafruit/RTClib

// RTC library declaration
RTC_DS3231 rtc;

// Choose Time Format *******************************************************
#define hourFormat        12     // 12 Hour Clock or 24 Hour Clock
// **************************************************************************

// Set fade in/out effect delay *********************************************
#define fadeDelay         12     // Best effect in range 5 - 20 milliseconds
// **************************************************************************

// Cathode poisoning prevention settings*************************************
// How often to run the cathode poisoning prevention routine
#define howOftenRoutine   1     // 0 - none, 1 - everytime, 
                                // 2 - every second time and so on
// **************************************************************************

// Set PWM frequency ********************************************************
// PWM frequency can be calculated by
// Freq = 48MHz CPU / (TCC0_prescaler 256 * (1 + period 99) * pwm divider)
uint32_t period = 100 - 1;      // Do not change the period!
#define PWM_Divider       15    // 24 - 78Hz, 15 - 125Hz, 10 - 188Hz 
// **************************************************************************

// NeoPixels LEDs pin
#define LED_PIN       A3

// Number of NeoPixels LEDs
#define LED_COUNT     4

// Declare our NeoPixel led object:
Adafruit_NeoPixel led(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);
// Argument 1 = Number of pixels
// Argument 2 = Arduino pin number
// Argument 3 = Pixel type flags:
// NEO_KHZ800  800 KHz bitstream for WS2812 LEDs
// NEO_GRB     Pixels are wired for GRB bitstream

// Blue backlight color
uint32_t hour_color = led.Color(0, 0, 255);
// Green backlight color
uint32_t minute_color = led.Color(0, 255,0);

// Shift registers control pins
#define DIN_PIN     A0
#define EN_PIN      A1
#define CLK_PIN     A2

// Nixie Power Supply Module control pin
#define EN_NPS_PIN  13 

// Declared as PA21, find below in code
// #define PWM_PIN    10

// The clock has a built-in detection mechanism 
// for 15 segment nixie tubes (e.g. B-7971, B-8971)
#define DETECT_PIN  A6    

int loopCounter = 0;

int analogDetectInput = 0;

// Serial monitor state
boolean serialState = 0;

// Bit numbers 
//
//            8
//       ___________
//      |\    |    /|
//      | \   |0  / |
//    9 | 1\  |  /7 | 13
//      |   \ | /   |
//      |____\|/____| 
//      | 2  /|\  6 |
//      |   / | \   |
//   10 |  /  |4 \  | 12
//      | /3  |  5\ |
//      |/    |    \|
//       ¯¯¯¯¯¯¯¯¯¯¯
//            11
//       /¯¯¯¯¯¯¯¯¯\
//            14    
//  ______________________
// | SOCKET 20A, 24A, 26A |
//  ¯¯¯¯¯|¯¯¯¯¯¯¯¯¯¯|¯¯¯¯¯

// Bit notation of 15-segment tube symbols                                  
uint16_t symbol_nixie_tube[]={
  0b0011111110001000,   // 0 
  0b0000000000010001,   // 1
  0b0010100101001000,   // 2
  0b0001100111000000,   // 3
  0b0011001001000100,   // 4
  0b0000101100100100,   // 5
  0b0001111101000100,   // 6
  0b0000000110010000,   // 7
  0b0011111101000100,   // 8
  0b0011101101000100,   // 9 
  0b0011011101000100,   // A
  0b0011100101010001,   // B 
  0b0000111100000000,   // C 
  0b0011100100010001,   // D 
  0b0000111100000100,   // E
  0b0000011100000100,   // F
  0b0001111101000000,   // G
  0b0011011001000100,   // H
  0b0000100100010001,   // I
  0b0011110000000000,   // J
  0b0000011010100100,   // K
  0b0000111000000000,   // L
  0b0011011010000010,   // M
  0b0011011000100010,   // N 
  0b0011111100000000,   // O 
  0b0010011101000100,   // P 
  0b0011111100100000,   // Q
  0b0010011101100100,   // R
  0b0001101101000100,   // S
  0b0000000100010001,   // T
  0b0011111000000000,   // U
  0b0000011010001000,   // V
  0b0011011000101000,   // W
  0b0000000010101010,   // X
  0b0000000010001010,   // Y
  0b0000100110001000    // Z             
};

uint16_t animation[]={
  0b0000000000000010,
  0b0000000000000001,
  0b0000000110000000,
  0b0010000101000000,
  0b0011000100100000,  
  0b0111000100010000,
  0b0111100100001000,
  0b0111110100000100,  
  0b0111111100000010,
  0b0111111100000001,
  0b0111111110000000,
  0b0111111101000000,
  0b0111111100100000,
  0b0111111100010000,
  0b0111111100001000,
  0b0111111100000100,
  0b0111111100000010,
  0b0111111100000001,
  0b0111111010000000,
  0b0101111001000000,
  0b0100111000100000,
  0b0000111000010000,
  0b0000011000001000,
  0b0000001000000100,
  0b0000000000000010, 
  0b0000000000000000     
};

// Nixie tube cathode no.14 (underscore symbol)
uint16_t hour_symbol = 0b0100000000000000;

// Underscore symbol flag, hour display distinguishing feature
// for multisegment tubes
// 0 - turn off, 1 - turn on
boolean hourUnderscore = 0;

// Bit notation of 10-segment tube digits 
uint16_t digit_nixie_tube[]={
  0b0000000000000001,   // 0 
  0b0000000000000010,   // 1
  0b0000000000000100,   // 2
  0b0000000000001000,   // 3
  0b0000000000010000,   // 4
  0b0000000000100000,   // 5
  0b0000000001000000,   // 6
  0b0000000010000000,   // 7
  0b0000000100000000,   // 8
  0b0000001000000000    // 9    
};

/*
// Bit notation of 7-segment tube digits
// Socket no.29, MG-17G nixie tube 
uint16_t digit_nixie_tube[]={
  0b0000000001110111,   // 0
  0b0000000000100100,   // 1
  0b0000000001011101,   // 2
  0b0000000001101101,   // 3
  0b0000000000101110,   // 4
  0b0000000001101011,   // 5
  0b0000000001111011,   // 6
  0b0000000000100101,   // 7
  0b0000000001111111,   // 8
  0b0000000001101111    // 9    
};
*/

// LEDs brightness matching values with nixie fade in out effect
uint8_t brightnessTable[50]={
    0,  10,  20,  30,  40,  50,  60,  70,  90,  90, 
  100, 110, 120, 110, 120, 126, 132, 138, 146, 152, 
  157, 163, 168, 174, 180, 186, 191, 196, 201, 205, 
  211, 214, 217, 220, 223, 226, 229, 232, 235, 238, 
  241, 243, 245, 247, 249, 251, 252, 253, 254, 255
};

void setup() 
{  
// Enable and configure generic clock generator 4
  GCLK->GENCTRL.reg = GCLK_GENCTRL_IDC |          // Improve duty cycle
                      GCLK_GENCTRL_GENEN |        // Enable generic clock gen
                      GCLK_GENCTRL_SRC_DFLL48M |  // Select 48MHz as source
                      GCLK_GENCTRL_ID(4);         // Select GCLK4
  while (GCLK->STATUS.bit.SYNCBUSY);              // Wait for synchronization

  // Set clock divider to generic clock generator 4
  GCLK->GENDIV.reg = GCLK_GENDIV_DIV(PWM_Divider) | // Divide 48 MHz
                     GCLK_GENDIV_ID(4);             // Apply to GCLK4 4
  while (GCLK->STATUS.bit.SYNCBUSY);                // Wait for synchronization
  
  // Enable GCLK4 and connect it to TCC0 and TCC1
  GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN |        // Enable generic clock
                      GCLK_CLKCTRL_GEN_GCLK4 |    // Select GCLK4
                      GCLK_CLKCTRL_ID_TCC0_TCC1;  // Feed GCLK4 to TCC0/1
  while (GCLK->STATUS.bit.SYNCBUSY);              // Wait for synchronization

  // Divide counter by 256
  TCC0->CTRLA.reg |= TCC_CTRLA_PRESCALER(TCC_CTRLA_PRESCALER_DIV256_Val);
  while (TCC0->SYNCBUSY.bit.WAVE);                // Wait for synchronization

  // Use "Normal PWM" (single-slope PWM): count up to PER, match on CC[n]
  TCC0->WAVE.reg = TCC_WAVE_WAVEGEN_NPWM;         // Select NPWM as waveform
  while (TCC0->SYNCBUSY.bit.WAVE);                // Wait for synchronization

  // Set the period (the number to count to (TOP) before resetting timer)
  TCC0->PER.reg = period;
  while (TCC0->SYNCBUSY.bit.PER);

  // Set PWM signal to output
  TCC0->CC[3].reg = period / 1;
  while (TCC0->SYNCBUSY.bit.CC2);

  // Configure PA21 (D10 on Arduino Nano 33 IoT) to be output
  PORT->Group[PORTA].DIRSET.reg = PORT_PA21;      // Set pin as output
  PORT->Group[PORTA].OUTCLR.reg = PORT_PA21;      // Set pin to low

  // Enable the port multiplexer for PA21
  PORT->Group[PORTA].PINCFG[21].reg |= PORT_PINCFG_PMUXEN;

  // Connect TCC0 timer to PA21. Function F is TCC0/WO[2] for PA21.
  // Odd pin num (2*n + 1): use PMUXO
  // Even pin num (2*n): use PMUXE
  PORT->Group[PORTA].PMUX[10].reg = PORT_PMUX_PMUXO_F;

  // Enable output (start PWM)
  TCC0->CTRLA.reg |= (TCC_CTRLA_ENABLE);
  while (TCC0->SYNCBUSY.bit.ENABLE);              // Wait for synchronization

  Serial.begin(9600);
  rtc.begin();  
   
  led.begin();                                    // Initialize NeoPixel led object     
  led.show();                                     // Turn OFF all pixels ASAP
 
  pinMode(EN_NPS_PIN, OUTPUT);
  digitalWrite(EN_NPS_PIN, HIGH);                 // Turn OFF nixie power supply module 

  pinMode(EN_PIN, OUTPUT);
  digitalWrite(EN_PIN, LOW);
  
  pinMode(CLK_PIN, OUTPUT);
  digitalWrite(CLK_PIN, LOW);
  
  pinMode(DIN_PIN, OUTPUT);
  digitalWrite(DIN_PIN, LOW);
      
  digitalWrite(EN_NPS_PIN, LOW);                  // Turn ON nixie power supply module      

  delay(5000);

  Serial.println("##############################################################");
  Serial.println("---------------------Classic Nixie Clock ---------------------");
  Serial.println("---------------- If you want to set new Time -----------------");
  Serial.println("----------- press ENTER for Arduino IDE up to 1.8 ------------"); 
  Serial.println("----------- press CTRL+ENTER for Arduino IDE 2.0 -------------"); 

  // Millis time start
  unsigned long millis_time_now = millis();
  unsigned long millis_time_now_2 = millis();
    
  // Wait 10 seconds
  while((millis() < millis_time_now + 10000))
  {         
    if (millis() - millis_time_now_2 > 160)
    {
      Serial.print("#");
      millis_time_now_2 = millis();    
    }

    // Set serialState flag if time settings have been selected 
    if(Serial.available() > 0) 
    {            
      serialState = 1;
      break;  
    }
  }

  Serial.println('\n');
    
  // Clear serial buffer
  while(Serial.available())
  Serial.read();

  if(serialState == 0)
  {
    // Turn on the nixie power module if settings have not been selected
    digitalWrite(EN_NPS_PIN, LOW); 
  }   
}

void loop() 
{
  loopCounter++;

  // Set a new time if settings have been selected
  if(serialState == 1)
  {
    SetNewTime();
    serialState = 0;
    
    // Turn ON nixie power supply module
    digitalWrite(EN_NPS_PIN, LOW);         
  }    

  // Get time from RTC and display on nixie tubes
  DisplayTime();
  
  // How often to run the cathode poisoning prevention routine
  if(loopCounter == howOftenRoutine) 
  {
    CathodePoisoningPrevention();
    loopCounter = 0;
  }
}

void SetNewTime()
{ 
  Serial.println("--------------- Enter the TIME without spaces ----------------");
  Serial.println("--------------- in the HHMM format e.g. 0923 -----------------");
  Serial.println("------- and when you are ready to send data to the RTC -------");
  Serial.println("------------ press ENTER for Arduino IDE up to 1.8 -----------"); 
  Serial.println("------------ press CTRL+ENTER for Arduino IDE 2.0 ------------"); 
  Serial.println('\n');

  // Clear serial buffer
  while(Serial.available())
  Serial.read();
    
  // Wait for the values
  while (!Serial.available()) {}                      

  // Read time as an integer value
  int hhmm_time = Serial.parseInt();

  // Extract minutes and hours
  byte timeSecond = 0;
  byte timeMinute = (hhmm_time / 1) % 100;
  byte timeHour   = (hhmm_time / 100) % 100;
  
  rtc.adjust(DateTime(0, 0, 0, timeHour, timeMinute, 0));             
}

void DisplayTime()
{
  DateTime now = rtc.now();
 
  byte timeHour = now.hour();
  byte timeFormat = hourFormat;
    
  // Check time format and adjust
  if(timeFormat == 12 && timeHour > 12) timeHour = timeHour - 12;
  if(timeFormat == 12 && timeHour == 0) timeHour = 12; 

  byte timeMinute = now.minute();
  byte timeSecond = now.second();

  Serial.print("Time: ");
  if(timeHour < 10)   Serial.print("0");
  Serial.print(timeHour);
  Serial.print(":");
  if(timeMinute < 10) Serial.print("0");
  Serial.print(timeMinute);  
  Serial.print(":");
  if(timeSecond < 10) Serial.print("0");
  Serial.println(timeSecond);      

  int digit;

  // Underscore symbol turn on for multisegment tubes
  hourUnderscore = 1; 
  
  // Extract individual digits
  digit  = (timeHour / 10) % 10;
  NixieDisplay(digit, hour_color);
  
  digit  = (timeHour / 1)  % 10;
  NixieDisplay(digit, hour_color);
    
  delay(500);

  // Underscore symbol turn off for multisegment tubes
  hourUnderscore = 0; 
  
  digit  = (timeMinute / 10) % 10;
  NixieDisplay(digit, minute_color); 
   
  digit  = (timeMinute / 1)  % 10;
  NixieDisplay(digit, minute_color);    
}

// If a high state appears on the analog input, 
// it means that a multi-segment tube socket has been inserted
bool DetectNixieTube()
{
  analogDetectInput = analogRead(DETECT_PIN);
  // 0 - 1024, Detecting anything above 0 means true
  // 950 is for sure 
  if(analogDetectInput >= 950) return(true);
  else return(false);  
}

void UpdatePWM(uint16_t pwmValue)
{
  TCC0->CC[3].reg = pwmValue;
  while (TCC0->SYNCBUSY.bit.CC2);
  
  TCC0->CTRLBSET.reg = TCC_CTRLBCLR_CMD_RETRIGGER;    // Restart the timer
  while(TCC0->SYNCBUSY.bit.CTRLB);                    // Wait for synchronization
}

void StopPWM ()
{
  TCC0->CTRLBSET.reg = TCC_CTRLBCLR_CMD_STOP;         // Stop the timer
  while(TCC0->SYNCBUSY.bit.CTRLB);                    // Wait for synchronization
}

void NixieDisplay(uint16_t digit, uint32_t backlight_color)
{
  if(DetectNixieTube() == true) ShowSymbol(digit, backlight_color);
  else ShowDigit(digit, backlight_color);
}


void SetLedBrightness(uint16_t baseBrightness, uint32_t backlight_color)
{  
  if (baseBrightness > 0) baseBrightness = (baseBrightness / 2) - 1;

  led.setBrightness(255-brightnessTable[baseBrightness]);     // Set brightness 0 - 255   
  led.fill(backlight_color);                                  // Fill all LEDs with a color
  led.show();                                                 // Update LEDs
}

// PWM fade in/out effect
void ShowDigit(uint16_t digit, uint32_t backlight_color)
{         
  ShiftOutData(digit_nixie_tube[digit]);
          
  for(int i = 100; i > 0; i = i - 2)
  { 
    UpdatePWM(i);
    SetLedBrightness(i, backlight_color);
    delay(fadeDelay);
  }

  delay(500);

  for(int i = 0; i <= 100 ; i = i + 2)
  { 
    UpdatePWM(i);
    SetLedBrightness(i, backlight_color);
    delay(fadeDelay);
  }     

  ClearNixieTube();  
}

// PWM fade in/out effect
void ShowSymbol(uint16_t digit, uint32_t backlight_color)
{        
  uint16_t currentDigit;

  if(hourUnderscore == 1) currentDigit = symbol_nixie_tube[digit] | hour_symbol;
  else currentDigit = symbol_nixie_tube[digit];   
   
  delay(100);

  ShiftOutData(currentDigit);
          
  for(int i = 100; i > 0; i = i - 2)
  { 
    UpdatePWM(i);
    SetLedBrightness(i, backlight_color);     
    delay(fadeDelay);
  }

  delay(500);

  for(int i = 0; i <= 100 ; i = i + 2)
  { 
    UpdatePWM(i);
    SetLedBrightness(i, backlight_color);
    delay(fadeDelay);
  }        
  
  ClearNixieTube();  
  //delay(100); 
}

// Turn off nixie tube
void ClearNixieTube()
{
  ShiftOutData(0);  
}

void CathodePoisoningPrevention()
{
  StopPWM();
  delay(500);

  // 15 cathodes nixie tube 
  if(DetectNixieTube() == true)
  {
    for(int i = 0; i < 26; i++)
    {
      ShiftOutData(animation[i]); 
      delay(80);
    }
  }
  else  // 10 cathodes nixie tube
  {
    for(int i = 0; i <= 3; i++)
    {
      for(int j = 0; j < 10; j++)
      {
        ShiftOutData(digit_nixie_tube[j]); 
        delay(80);
      }
    }  
  }
  
  ClearNixieTube();
  delay(1000);
}

void ShiftOutData(uint16_t character)
{ 
  uint8_t first_half = character >> 8;  
  uint8_t second_half = character;     
  digitalWrite(EN_PIN, LOW);
  shiftOut(DIN_PIN, CLK_PIN, MSBFIRST, first_half);
  shiftOut(DIN_PIN, CLK_PIN, MSBFIRST, second_half);
      
  // Return the latch pin high to signal chip that it
  // no longer needs to listen for information
  digitalWrite(EN_PIN, HIGH);
}