#include <SoftPWM.h>

const int  delayTime   = 200;
const int  longDelay   = 500;
const int  shortDelay  =   5;
const int  fadeSteps   =   50;
const int  fadePause   =    2;
const int pins[] = {12, 11, 10, 9, 8, 7, 6, 5, 4};

void setup() {
  for (int i = 0; i < 9; i++) {
    pinMode(pins[i], OUTPUT);
    SoftPWMSet(pins[i], 0);
  }
  SoftPWMBegin();
}

void loop() {
  // 1) Fade in/out seq1: {11}, then {8}, then {5}
  int s1a[] = {11}; fadeSequence(s1a, 1, true);  delay(delayTime);
               fadeSequence(s1a, 1, false); delay(delayTime);
  int s1b[] = {8};  fadeSequence(s1b, 1, true);  delay(delayTime);
               fadeSequence(s1b, 1, false); delay(delayTime);
  int s1c[] = {5};  fadeSequence(s1c, 1, true);  delay(delayTime);
               fadeSequence(s1c, 1, false); delay(delayTime);

  // 2) Fade in/out seq2: {4}, {7}, {10}
  int s2a[] = {4};  fadeSequence(s2a, 1, true);   delay(delayTime);
               fadeSequence(s2a, 1, false);  delay(delayTime);
  int s2b[] = {7};  fadeSequence(s2b, 1, true);   delay(delayTime);
               fadeSequence(s2b, 1, false);  delay(delayTime);
  int s2c[] = {10}; fadeSequence(s2c, 1, true);   delay(delayTime);
               fadeSequence(s2c, 1, false);  delay(delayTime);

  // 3) Fade {9}, then group {6,12}, then back out, then {9}
  int g3a[] = {9};    fadeSequence(g3a, 1, true);   delay(delayTime);
  int g3b[] = {6, 12};fadeSequence(g3b, 2, true);   delay(delayTime);
                     fadeSequence(g3b, 2, false);  delay(delayTime);
                     fadeSequence(g3a, 1, false);  delay(delayTime);

  // 4) Fade {11,4}, then {8,7}, then back out {8,7}, then back out {11,4}
  int g4a[] = {11, 4};fadeSequence(g4a, 2, true);   delay(delayTime);
  int g4b[] = {8,  7};fadeSequence(g4b, 2, true);   delay(delayTime);
                     fadeSequence(g4b, 2, false);  delay(delayTime);
                     fadeSequence(g4a, 2, false);  delay(delayTime);

  // 5) Three stages of 6-pin fades with holds
  int st1[] = {12, 11, 8, 7, 6, 4};
  fadeSequence(st1, 6, true);  delay(longDelay);
  fadeSequence(st1, 6, false); delay(shortDelay);

  int st2[] = {9, 8, 5, 4, 12, 10};
  fadeSequence(st2, 6, true);  delay(longDelay);
  fadeSequence(st2, 6, false); delay(shortDelay);

  int st3[] = {6, 5, 11, 10, 9, 7};
  fadeSequence(st3, 6, true);  delay(longDelay);
  fadeSequence(st3, 6, false); delay(shortDelay);
}

// Fade one or more pins up (in=true) or down (in=false)
void fadeSequence(int group[], int count, bool in) {
  if (in) {
    for (int step = 0; step <= fadeSteps; ++step) {
      uint8_t val = map(step, 0, fadeSteps, 0, 255);
      for (int i = 0; i < count; ++i) {
        SoftPWMSet(group[i], val);
      }
      delay(fadePause);
    }
  } else {
    for (int step = fadeSteps; step >= 0; --step) {
      uint8_t val = map(step, 0, fadeSteps, 0, 255);
      for (int i = 0; i < count; ++i) {
        SoftPWMSet(group[i], val);
      }
      delay(fadePause);
    }
  }
}