The three sides of the triangle are connected in parallel. Even though there are 18 bicolor LEDs (36 individual LED elements), the PIC16f628A is controlling only 6 bicolor LEDs (12 individual elements) and these are duplicated around the triangle.
This is the first project where I tried using bicolor LEDs. Since the SLAK platform drives at most 12 LEDs, this ends up with only 6 bicolor LEDs. And although running animations on six red/yellow/green LEDs is nice, I thought it would be more interesting to find some other arrangement. While looking around for inspiration I saw a triangle design that was made of three parallelograms. I realized that this would be a great shape for the LEDs.
Between the triangular arrangement, the red, green, and yellow color possibilities, and the transitions, it is possible to create a large number of different animations. In the current code, the animation sequence takes 10 minutes to repeat. For the video I created a build that runs each animation sequence only twice, so that the video is only 2 minutes long.
(Pictures and download link after the jump)
The picture here shows the project built on a two-level triangular base hung on the wall. I did not originally intend to have a two-level base, but this is what happens when you don't think all the way through the design. I first created the small white triangle, drilled the holes, wired (wire-wrapped) the LEDs, and connected them to the proto board. I spent some time working on the animations. Then, when I went to design a PCB, I realized that the white board was too small for my PCB, so I had to come up with a bigger triangle to put the PCB behind.
For this particular project I used a 5v voltage regulator. It would have been better just to find a regulated power supply, since they are becoming very common. If you are going to build this I would recommend simply leaving off the regulator and capacitors and using a regulated supply.
This diagram is the LED layout on the smaller white triangle. Right-click to save the original jpeg file, then print at 150dpi. At 150dpi the lead spacing for the LEDs is 0.1in. I taped this to the wood before drilling the holes.