Cleaned up code. Added some comments.

Author: sowbug

examples/Ticon2011/Ticon2011.ino

@@ -1,24 +1,27 @@
 /* -*- mode: c; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*-
 
-  G35: An Arduino library for GE Color Effects G-35 holiday lights.
-  Copyright © 2011 The G35 Authors. Use, modification, and distribution are
-  subject to the BSD license as described in the accompanying LICENSE file.
+   G35: An Arduino library for GE Color Effects G-35 holiday lights.
+   Copyright © 2011 The G35 Authors. Use, modification, and distribution are
+   subject to the BSD license as described in the accompanying LICENSE file.
 
-  Ticon2011.ino is the code that I used for Christmas 2011 at my home. It's yet
-  another demonstration of working code.
+   Ticon2011.ino is the code that I used for Christmas 2011 at my home. It's yet
+   another demonstration of working code.
 
-  By Mike Tsao <github.com/sowbug>. See README for complete attributions.
+   By Mike Tsao <github.com/sowbug>. See README for complete attributions.
 */
 
 // If defined, then a 38KHz IR receiver is supplying data on pin 11. I didn't
 // really use this much; if it detects any recognized remote code, it skips to
 // the next program. So in theory people driving by my house who happen to have
 // a TV remote in their car could stop and change the program.
+//
+// Pretty much any of these IR receivers will work. I used a Vishay Semi
+// TSOP58038 (http://octopart.com/partsearch#search/requestData&q=TSOP58038).
 #define USE_REMOTE 1
 
 // If defined, then the hardware is an Arduino. If not, then it's a Teensy.
-// More described below. I used this because I had an Arduino in the house
-// when I was writing new programs, then ran outside in the cold with my
+// More described below. I used this switch because I had an Arduino in the
+// house when I was writing new programs, then ran outside in the cold with my
 // laptop to reprogram the Teensy that was running the real lights.
 #define ARDUINO 1
 
@@ -28,21 +31,24 @@
 #include <StockPrograms.h>
 #include <PlusPrograms.h>
 #ifdef USE_REMOTE
+// Get at https://github.com/shirriff/Arduino-IRremote
 #include <IRremote.h>
 #endif
 
 #ifdef ARDUINO
 // A regular Arduino. First string on pin 13, second on 12.
 G35String lights_1(13, 50, 50, 0, false);
 G35String lights_2(12, 41);
+
 #ifdef USE_REMOTE
-IRrecv ir(11);
+IRrecv ir(11);  // IR receiver on pin 11.
 decode_results ir_results;
 #endif
+
 #else
 // A Teensy 2.0 that's been flashed with the Arduino Leonardo bootloader (thus
 // permanently destroying the HalfKay bootloader that ships with the Teensy).
-// The first string is connected to D6, and the second to B4. 
+// The first string is connected to D6, and the second to B4.
 G35String lights_1(12, 50, 50, 0, false);
 G35String lights_2(8, 41);
 #endif
@@ -55,13 +61,12 @@ PlusProgramGroup plus_programs;
 G35StringGroup string_group;
 
 LightProgram* CreateProgram(uint8_t program_index) {
-  randomSeed(rand() + analogRead(0));
-  program_index = rand() % PROGRAM_COUNT;
+  program_index = random() % PROGRAM_COUNT;
 
-  if (program_index < StockProgramGroup::ProgramCount) { 
-    return stock_programs.CreateProgram(string_group, program_index); 
-  } 
-  program_index -= StockProgramGroup::ProgramCount; 
+  if (program_index < StockProgramGroup::ProgramCount) {
+    return stock_programs.CreateProgram(string_group, program_index);
+  }
+  program_index -= StockProgramGroup::ProgramCount;
 
   if (program_index < PlusProgramGroup::ProgramCount) {
     return plus_programs.CreateProgram(string_group, program_index);
@@ -76,9 +81,31 @@ LightProgram* CreateProgram(uint8_t program_index) {
 
 ProgramRunner runner(CreateProgram, PROGRAM_COUNT, PROGRAM_DURATION_SECONDS);
 
+// http://www.utopiamechanicus.com/77/better-arduino-random-numbers/
+// We assume A0 and A1 are disconnected.
+uint32_t seedOut(unsigned int noOfBits) {
+  uint32_t seed = 0, limit = 99;
+  int bit0 = 0, bit1 = 0;
+  while (noOfBits--) {
+    for (int i = 0; i < limit; ++i) {
+      bit0 = analogRead(0) & 1;
+      bit1 = analogRead(1) & 1;
+      if (bit1 != bit0)
+        break;
+    }
+    seed = (seed << 1) | bit1;
+  }
+  return seed;
+}
+
 void setup() {
-  randomSeed(analogRead(0));
-  Serial.begin(57600);
+  uint32_t seed = seedOut(32);
+  randomSeed(seed);
+  seed &= 0xff;
+  // random() isn't very random. But this seed generator works quite well.
+  while (seed--) {
+    random();
+  }
 
 #ifdef USE_REMOTE
   ir.enableIRIn();
@@ -87,7 +114,6 @@ void setup() {
   delay(50);
   lights_1.enumerate();
   lights_2.enumerate();
-  delay(50);
 
   lights_1.do_test_patterns();
   lights_2.do_test_patterns();
@@ -101,7 +127,6 @@ void loop() {
 
 #ifdef USE_REMOTE
   if (ir.decode(&ir_results)) {
-    Serial.println(ir_results.value, HEX);
     runner.switch_program();
     ir.resume();
   }