Pixels a beginners guide

This is the place to start off learning about Pixels. NOTE: individual controllers, pixel strips / nodes, troubleshooting, and other non basic items will not be covered in this Wiki please look for the correct Wiki for your specific questions.

So your interested in learning about pixels, they are an amazing technology that is growing rapidly in DIY lighting. Throughout this intro Wiki there will be some concepts that may be difficult to soak in all at once, refer back to this as necessary.

A basic idea of how Pixels work verses the more traditional lighting in computer controlled shows:

Traditional lighting and their controllers function like a dimmer switch on the wall, the light is on or off and varies in intensity based on the position of the dimmer switch. Each dimmer switch is its own channel and a show consists of several to several hundred switches. To help ease the amount of boxes most of these switches are conveniently placed in groups of them on a board, you will find boards that have 8,12,16 or even up to 48 switches on a single board allowing for one connection to control a great number of lights cutting down on clutter. The boards are controlled by a signal generated by a computer running software that sends the signals, the boards figure out what switch is being referenced in the signal and adjusts the correct switch making all lights plugged into the switch dim/brighten.

Pixels are different in that the switch does not control the whole light, instead each pixel is comprised of 3 lights, one red, one green, and one blue light. So each pixel needs 3 switches to make it function.

Pixels are divided up in that they come in 2 different ways. The pixel nodes look more like traditional lights there is the pixel "bullet" and a run of wire attaching another pixel "bullet" and so on. These give the look of traditional lights with the exception they can change color. The other is called a pixel strip, this arrangement is a long narrow strip that has the pixels attached to it, the pixels are close together and give the appearance of neon when viewed at a distance. It is up to the individual as to whether to use nodes or strips based on how you want your lights to look. Both strips and nodes function the same, only their appearance is different.

Some pixels are referred to as dumb, in these the 3 switches for the pixel are on the board much like traditional lighting, also like traditional lighting the entire string of pixels light up the same color.

There is also what is referred to as smart pixels, in these the switches are in each pixel, these may have several hundred switches in a single light strand. Smart pixel controller boards are there to divide up the signal to make sure the light strand gets the signal that is supposed to go to that strand. Smart pixels each pixel can be any color at any time.

As we can see from the above there is a lot to consider when opting for pixels.

A quick overview of how the boards receive their signals

There is a myriad of different protocols that are used today, think of different cell phone companies, there is no right or wrong protocol just as there is no right or wrong cell phone company. The protocol is just a way of getting the signal from your computer to the controller board. The pixels themselves have their own native language they speak, but just like your cell phone its range is limited, usually less than 20 feet between individual pixels. The protocol carries that native language to the various controller boards, and is able to cover the distances needed between controllers and computer. Some boards will need a bridge to convert the carrier protocol to a signal that can communicate with the board, check with your individual board to see what is needed.

Identity and pixels

How does each switch know what part of the signal applies to it? Think of your phone number here, each switch is assigned a number by the computer software, just like a phone number there can be enough different numbers that it will be hard to know what is what. We have area codes on our phone numbers to help distinguish what goes where, in the pixel world we divide switches up into a 512 switch grouping and call that a universe. So our carrier sends a signal, that signal starts with what universe the next 512 "channels" are in, when talking about the signal each switch is referenced as a channel. We then assign the bridges or boards to "listen" to certain universes. We can even assign boards to only select certain channels inside of that universe.

So we have an idea of how the pixels and protocols work, now lets cover some basics about the controllers.

Please note specific boards is beyond the scope of this wiki and will not be answered

In a dumb pixel board the board is assigned what universe and what start channel it is supposed to use. In a dumb controller, output 1 is the first 3 channels assigned to the board, output 2 is the next 3 channels assigned to the board and so on. Dumb pixel controllers can, for example, control 3 channels (a single strand) to 27 channels (9 strands) and beyond. You can hook together more than one strand just like you can hook traditional lights together, all strands connected together will be the same color.

In a smart Pixel controller board the board is not directly assigned universe or channel numbers, instead each output on the board is assigned what universe and channel number it starts with. Instead of having the switches on the board they are in the individual pixels, so the board sends a native language signal out on each output that starts with the correct universe and channel that is assigned to the output, when the first pixel gets that signal it uses the first 3 channels (remember each pixel has 3 switches) then "regenerates" the signal marking the 3 it used and sends the signal on its way to the next pixel, the next pixel uses the first 3 unmarked channels, regenerates marking the 3 channels it used and so on down the string. This way each pixel uses the correct channels and transfers the signal down its length. You can connect several strings of lights together using this but any pixels past the last channel on the universe will not have data and will not work.

So we have covered the general concept of pixels hopefully this will help to clear some of the fog.