Hello there,
Well that is nice of you to say, and thanks much.
As Nigel thankfully pointed out, the controller for this was the Arduino Nano. I chose that module because it is self contained and ready to go, and maybe more important, it's SMALL. It's only about three quarters of an inch wide by maybe 3 inches long, so it fits right on the tree in the bottom section without getting in the way at all. The board i used did not have headers on it either, like many of them do. I got it that way so i could hard wire it up to whatever i was going to use it for and that would make the electrical end of it more stable. The Nano also took only about 15 minutes to program with the random blink code using the Arduino IDE software set.
You might also note that this is probably the simplest tree you can make. Some other ideas you might like are:
1. You can go 3d, making the tree have depth as well as width and height, so you can have LEDs visible from the sides as well as the front.
2. You can go super 3d, where you make the entire tree out of LEDs running up all sides.
3. You can go super duper 3d with girth, where you actually fill the entire 3d cone space with RGB LED's, where each one is individually controlled. That would be the ultimate Christmas tree i think. The LEDs can then be illuminated not only at the surface of the tree, but actually inside the tree body also. The lighting/blinking pattern could be quite awesome to watch. Of course it would be much harder to build and you'd need several communicating controllers so you would have enough i/o pins to drive each LED RGB pins separately. They also make serial programmable RGB LEDs now too though, if you wanted to try those instead.