Make work with great variety of things

README.md

@@ -15,7 +15,7 @@ I found a good 10A power supply for about $12 on Amazon.
 You can probably salvage one from some old thing.
 
 If you have under 80 lights, you can use an Adafruit Trinket.
-I used an Adafruit Pro Trinket for mine, which has 150+ lights.
+I used an Adafruit Pro Trinket for my 182-light display.
 (It's an issue of RAM).
 
 Of course, a standard Arduino will work just fine too!
@@ -23,9 +23,9 @@ Of course, a standard Arduino will work just fine too!
 This was coded to color-correct a specific type of GRB LEDs on wires I got from Amazon.
 It's coded to match the lights we already have, which are biased toward yellow and amber.
 
-You may have gotten lights wired RGB, in which case this is going to look very green.
+You may have gotten lights wired GRB, in which case this is going to look very green.
 It should be just a matter of switching the first two bytes in each color definition
-to go from GRB to RGB.
+to go from RGB to GRB.
 
 
 
@@ -33,7 +33,6 @@ Setup
 -------
 
 Plug your lights into pin 6 (or whatever you set `PIN` to in the code).
-Set `NUM_LEDS` in the code to how many are in your strip.
 
 Give the strip power and ground.
 If you have more than about 80 LEDs, you might need to provide an external
@@ -42,7 +41,12 @@ You can plug the LED strip into the +5v on the power supply;
 You can power your microcontroller from the beefier power supply, too,
 so you don't have to run USB just to power the microcontroller.
 
-The code as written wants pin 4 to be connected to ground.
-When you disconnect it,
-the whole strand goes white.
-My family has a tradition of the tree going from colors to white on the morning of the 25th.
+
+Usage
+-------
+
+Just provide power.
+
+If you connect `WHITE_PIN` to ground,
+everything goes white,
+which is a tradition in my family on xmas morning.

holiday-lights.ino

@@ -3,21 +3,42 @@
   #include <avr/power.h>
 #endif
 
-#define PIN 6
-#define NUM_LEDS 150
+// Which pin your LED strip is connected to
+#ifdef Attiny85
+#  define PIN 3
+#else
+#  define PIN 6
+#endif
 
+// Which pin to pull to go full white. Comment to disable this feature.
 #define WHITE_PIN 4
 
-Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_GRB | NEO_KHZ800);
+// Order of the lights you got
+
+// How many LEDs you have. It's okay if this is too big.
+#ifdef Attiny85
+#  define NUM_LEDS 80
+#else
+#  define NUM_LEDS 200
+#endif
+
+// What percentage chance a chosen light has of being on
+#define ACTIVITY 50
+
+// Debug LED
+#define LED_PIN 1
+
+
+Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_RGB | NEO_KHZ800);
 
 const uint32_t colors[] = {
-  0x440000, // Green
-  0x44dd00, // Yellow
-  0x44dd00, // Yellow
-  0x22dd00, // Amber
-  0x22dd00, // Amber
-  0x00ff00, // Red
-  0x008844, // Purple
+  0x004400, // Green
+  0xdd4400, // Yellow
+  0xdd4400, // Yellow
+  0xdd2200, // Amber
+  0xdd2200, // Amber
+  0x0000ff, // Red
+  0x880044, // Purple
   0x000088, // Blue
 };
 
@@ -26,13 +47,19 @@ const int ncolors = sizeof(colors) / sizeof(*colors);
 void setup() {
   strip.begin();
   strip.show();
+#ifdef WHITE_PIN
   pinMode(WHITE_PIN, INPUT_PULLUP);
+#endif
+
+#ifdef LED_PIN
+  pinMode(LED_PIN, OUTPUT);
+#endif
 }
 
 void loop_color() {
   for (int i = 0; i < NUM_LEDS/12; i += 1) {
     int pos = random(NUM_LEDS);
-    if (random(100) < 20) {
+    if (random(100) < ACTIVITY) {
      int color = random(ncolors);
      strip.setPixelColor(pos, colors[color]);
    } else {
@@ -57,9 +84,19 @@ void loop_white() {
 }
 
 void loop() {
-  if (digitalRead(WHITE_PIN)) {
+#ifdef WHITE_PIN
+  if (! digitalRead(WHITE_PIN)) {
     loop_white();
   } else {
+#else
+  {
+#endif
     loop_color();
   }
+
+#ifdef LED_PIN
+  static bool led = true;
+  digitalWrite(LED_PIN, led);
+  led = !led;
+#endif
 }