Added all states, all sounds, this is usable

MusicPlayer.cpp

@@ -10,7 +10,7 @@ MusicPlayer::MusicPlayer(int8_t cs, int8_t dcs, int8_t dreq, int8_t cardcs)
 {
   musicPlayer = new Adafruit_VS1053_FilePlayer(cs, dcs, dreq, cardcs);
   musicPlayer->begin();
-  musicPlayer->setVolume(20, 20); // lower = louder
+  musicPlayer->setVolume(1, 1); // lower = louder
   musicPlayer->sineTest(0x44, 500);
   SD.begin(cardcs);
 }

ProtonPack.ino

@@ -65,22 +65,29 @@ void loop() {
 
   switch (state) {
   case 0:
-    if (trigger) {
-      if (music->startPlayingFile("track001.mp3")) {
+    if (trigger && music->startPlayingFile("track001.mp3")) {
       state = 1;
       sync1->charge();
     }
-    }
     break;
   case 1:
     if (! music->isPlaying()) {
-      if (music->startPlayingFile("track002.mp3")) {
-	state = 4;
-	sync1->standby();
+      state = 3;
     }
+    break;
+  case 3:
+    if (trigger && music->startPlayingFile("track003.mp3")) {
+      state = 4;
+      sync1->fire();
     }
     break;
   case 4:
+    if (! trigger && music->startPlayingFile("track002.mp3")) {
+      state = 5;
+      sync1->discharge();
+    }
+    break;
+  case 5:
     if (! music->isPlaying()) {
       state = 0;
     }

Synchrotron.cpp

@@ -12,29 +12,47 @@ Synchrotron::Synchrotron(uint16_t n, uint8_t p, neoPixelType t)
   cur = 0;
   pxl->begin();
   pxl->show();
+
+  // Inital values of 0 will make it look like it's sort of warming up
+  ticks = 0;
+  tickrate = 200;
+  r = 0;
+  g = 0;
+  b = 0;
+
   standby();
 }
 
+Synchrotron::transition(int duration, int final_tickrate, byte final_r, byte final_g, byte final_b)
+{
+  transition_length = duration;
+  transition_elapsed = 0;
+
+  dtickrate = (final_tickrate - tickrate) / (float)duration;
+  dr = (final_r - r) / (float)duration;
+  dg = (final_g - g) / (float)duration;
+  db = (final_b - b) / (float)duration;
+
+  initial_tickrate = tickrate;
+  initial_r = r;
+  initial_g = g;
+  initial_b = b;
+}
+
 Synchrotron::standby() {
-  tickrate = 12;
-  ticks = 0;
-  r = brightness;
-  g = 0;
-  b = 0;
+  transition(400, 12, brightness, 0, 0);
 }
 
 Synchrotron::charge() {
-  tickrate = 2;
-  ticks = 0;
-  r = brightness;
-  g = brightness / 8;
-  b = 0;
+  transition(400, 2, brightness, brightness/8, 0);
 }
 
 Synchrotron::fire() {
+  transition(40, 1, brightness/8, brightness/4, brightness/2);
 }
 
 Synchrotron::discharge() {
+  standby();
 }
 
 Synchrotron::tick(unsigned long jiffies) {
@@ -51,8 +69,16 @@ Synchrotron::tick(unsigned long jiffies) {
   pxl->show();
 
   ticks += 1;
-  if (ticks == tickrate) {
-    ticks = 0;
+  if (ticks >= tickrate) {
     cur = (cur + 1) % npixels;
+    ticks = 0;
+  }
+
+  if (transition_length > transition_elapsed) {
+    tickrate = initial_tickrate + (dtickrate * transition_elapsed);
+    r = initial_r + (dr * transition_elapsed);
+    g = initial_g + (dg * transition_elapsed);
+    b = initial_b + (db * transition_elapsed);
+    transition_elapsed += 1;
   }
 }

Synchrotron.h

@@ -10,8 +10,13 @@ class Synchrotron {
   int tickrate;	     // How many millis between pixel position changes
   int ticks; // How many ticks have elapsed since last position change
   byte r, g, b;			// Current color
+
+  int transition_length, transition_elapsed;
+  int initial_tickrate, initial_r, initial_g, initial_b;
+  float dtickrate, dr, dg, db;
 public:
   Synchrotron(uint16_t n, uint8_t p=6, neoPixelType t=NEO_GRB + NEO_KHZ800);
+  transition(int duration, int final_tickrate, byte final_r, byte final_g, byte final_b);
   standby();
   charge();
   fire();