// https://forum.arduino.cc/t/shift-register-code/1142032/8

#include <Adafruit_NeoPixel.h>
#define PIXPIN    2 // data pin for WS2812
#define NUMPIXELS 4 * 7 + 1 // 4 pixels/seg * 7 seg + decimal point
Adafruit_NeoPixel pixels(NUMPIXELS, PIXPIN, NEO_GRB + NEO_KHZ800);
// #define DELAYVAL 500 // Time (in milliseconds) to pause between pixels

int latchPin = 8; // ST_CP of 74HC595
int clockPin = 12;// SH_CP of 74HC595
int dataPin  = 11; // DS of 74HC595

// see digit-to-decimal conversion below
int hexDigits[] = {63, 6, 91, 79, 102, 109, 125, 7, 127, 103, 119, 124, 88, 94, 121, 113};

void setup() {
  //set pins to output because they are addressed in the main loop
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
}

void loop() {
  led7seg();
  pix7seg();
}

// **********************************************************************
// NEOPIX
// **********************************************************************
void pix7seg() {
  pixels.begin(); // INITIALIZE NeoPixel strip object (REQUIRED)
  pixels.clear(); // Set all pixel colors to 'off'

  for (int i = 0; i < 7; i++) { // segments
    for (int j = 0; j < 4; j++) { // pix / segment
      pixels.setPixelColor(i * 4 + j, pixels.Color(0, 255, 0));
      pixels.show();   // Send the updated pixel colors to the hardware.
    }
    delay(250);
  }
  pixels.setPixelColor(28, pixels.Color(0, 255, 0));
  pixels.show();   // Send the updated pixel colors to the hardware.

  delay(250);
  for (int i = 0; i < 7; i++) { // segments
    for (int j = 0; j < 4; j++) { // pix / segment
      pixels.setPixelColor(i * 4 + j, pixels.Color(0, 0, 0));
      pixels.show();   // Send the updated pixel colors to the hardware.
    }
    pixels.setPixelColor(28, pixels.Color(0, 0, 0));
  }
  pixels.show();   // Send the updated pixel colors to the hardware.
  delay(250);
}

void pixSeg(int seg, int state) {
    for (int j = 0; j < 4; j++) { // pix / segment
      pixels.setPixelColor(j * 4 + j, pixels.Color(0, 0, 0));
    }
}

// **********************************************************************
// LED
// **********************************************************************
void led7seg() {
  for (int i = 0; i < 16; i++) {
    update595(hexDigits[i]);
    delay(500);
    update595(128);
    delay(500);
  }
}

void update595(int value)
{
  digitalWrite(latchPin, LOW); // ground latchPin
  shiftOut(dataPin, clockPin, MSBFIRST, value); // write the data to the data pin
  digitalWrite(latchPin, HIGH); // return the latchpin high
}

/*
  **************************
  WS2812
  **************************
  SEG  leds[x]
   A    0 -  3
   B    4 -  7
   C    8 - 11
   D   12 - 15
   E   16 - 19
   F   20 - 23
   G   24 - 27
  DP   28

  DIG  SEGMENTS
   0   A, B, C, D, E, F
   1   B - C  4 - 11
   2   A, B, D, E, G
   3   A, B, C, D, G
   4   B, C, f, G
   5   A, C, D, F, G
   6   A, C, D, E, F, G
   7   A, B, C
   8   A, B, C, D, E, F, G
   9   A, B, C, D, F, G
   A   A, B, C, E, F, G
   B   C, D, E, F, G
   C   D, E, G
   D   B, C, D, E, G
   E   A, D, E, F, G
   F   A, E, F, G
   DP  DP

  **************************
  7-segment LED
  **************************
  Bit value   DEC   Segment
  0000 0001 =   1 = A
  0000 0010 =   2 = B
  0000 0100 =   4 = C
  0000 1000 =   8 = D
  0001 0000 =  16 = E
  0010 0000 =  32 = F
  0100 0000 =  64 = G
  1000 0000 = 128 = DP

  DIG   BIN      DEC  HEXDIG
  0 0011 1111 = 0x3F =  63
  1 0000 0110 = 0x06 =   6
  2 0101 1010 = 0x5A =  91
  3 0100 1111 = 0x4F =  79
  4 0110 0110 = 0x66 = 102
  5 0110 1101 = 0x6D = 109
  6 0111 1101 = 0x7D = 125
  7 0000 0111 = 0x07 =   7
  8 0111 1111 = 0x7F = 127
  9 0110 1111 = 0x6F = 103
  A 0111 0111 = 0x77 = 119
  b 0111 1100 = 0x7C = 124
  c 0101 1000 = 0x58 =  88
  D 0101 1110 = 0x5E =  94
  E 0111 1001 = 0x79 = 121
  F 0111 0001 = 0x71 = 113
*/