Smart Pixel Technology Question

[longhorn]

I have wondered about this question for several years now, and I thought the smart folks here probably know the answer.  My question relates to how the individual smart pixels know which data applies to them.  Let's say I have a strand of 50 smart pixels.  When the controller sends the data to the strand, how does the first pixel know it is number 1, and the 50th know it is number 50?

Originally, I thought that the strand probably comes with some type of pixel ID built-in (e.g. ID 1-50), such that each pixel circuit just looks at the data related to its pixel ID (similar to a controller only pulling data for its Unit ID).  However, if this was the case, it wouldn't explain how a second strand connected to the first strand would know that its first pixel is 51 (instead of pulling the data for pixel 1).

My current guess is that the data is sent in order of pixels (regardless of how many strands), and then each pixel picks up the first packet of RGB data it sees and  somehow removes that packet before the data heads to the next pixel.  This way each pixel just uses the first data it sees.

Now that I've thrown out my complete guesses, anybody know how it really works?  I guess it doesn't really matter since it just works, but I would kind of like to understand it.

[k6ccc]

7 minutes ago, longhorn said:

My current guess is that the data is sent in order of pixels (regardless of how many strands), and then each pixel picks up the first packet of RGB data it sees and  somehow removes that packet before the data heads to the next pixel.  This way each pixel just uses the first data it sees.

Ding, Ding, Ding.  As for the second part, each pixel reads the data string, strips off the first set of RGB data that it receives and then regenerates the remainder of the string data.  So each pixel thinks that it is the first pixel in the string.  One huge advantage of that is that if a pixel fails and you replace it, there is no configuration required to make it work right.

Note that there are exceptions that do it different.  The old GE Color Effects lights have an initialization routine where the controller and pixels figure out who is who when powered up.