This is an attempt to document what I did to get this working. It is not a good final solution, but maybe someone will run with it and create a nice kit. I don't really have the time myself.
1. Install a ColorDMD and update to the newer SIGMA firmware with the color changing feature. See this thread:
http://pinside.com/pinball/forum/topic/new-from-colordmd-why-pick-just-one
2. You need to tap into the signals that drive the ramp LEDs. This is a frankenstein method using stuff I had laying around. Note that my kit is one of the prototypes and the pinout is different for the ones that Pinbits is now selling.
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3. I had to modify the signals slightly. Basically, I'm using a microcontroller to switch from one set of inputs (left ramp) to the other (right ramp) once per second. I then invert them (low logic input = high logic output). The microcontroller is inside the heat shrink.
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4. Finally, connect to the ColorDMD as Randy described, except I'm using 5V logic rather than 12V. The ColorDMD is easily capable of handling the 5V logic as is.
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You could take this in two different directions.
1. Randy could take the microcontroller stuff and move it into the ColorDMD firmware, and then we would only need a dumb cable.
2. You could keep the microcontroller external, add transistors to the MCUs outputs, and add a 12V power source with enough current capability to drive your devices. What devices, you ask? Any of the stuff that the LED strip controller boxes now handle. So, you could have the ColorDMD, speaker lights, under-cabinet lighting, toppers, etc. all synchronized to the Pinbits / Eli ramps.
Anyway, here's a slightly better video (once it finishes uploading) than the one in the original thread to allow you to see what my machine is doing now.
And the original video: