The Nearly Famous RGB Video Series - Everything You Wanted To Know About Pixels But Couldn't Find The Answer

When I started researching RGB and pixel solutions in early 2010, there was just about no information on the internet as to what all the teminolgy, protocols, wiring, controllers and other items were.  After extensive research and work with others, I decided to document all the information I knew at the time in the form of a video series.  The focus behind the videos was to simply show each type of lighting, controller, wiring, etc in a non-vendor specific manner so that someone just getting started out could get up to speed on the terminolgy and functions.  This information, while produced in late 2010, early 2011 is older now, every bit of it is still completely relevant.  Since this information is squirrled away on our website, I though I would repost it here for those new to RGB and pixels.

The videos below cover the general topics of RGB as they relate to Holiday Lighting.

Video #1 What is RGB? What are the different type of RGB lighting devices? What is Basic RGB and RGB Pixels? How to Pixels get their addresses? How do you assign channels to pixels? What are controller macros?
Video #2 How do I fix dead pixels? What is the difference between three and four wire pixels?  Does it matter? How do I know which end of my pixels to hook to the controller?  Does it matter? How do I power my pixels? Why are there different voltages for pixels? What is the difference between centralized and de-centralized power distribution of pixels? How many pixels can be on a single controller output? What is color depth in pixels?  Why does it matter?
Video #3 What are the different type of pixel chips? What quality issues should I be aware of when purchasing pixels? What are the drawbacks of RGB over just regular Christmas lights? What advantage do Basic RGB and RGB Pixels give me?
Video #4 What are the different types of Basic RGB controllers? Why would I want to use basic RGB controllers and LEDs instead of pixel based controllers and LEDs? What are the different types of RGB Pixel controllers?

Outlining Your House in RGB Lights - Detailed Design Guide (Updated for 2026)

Updated September 2026. We rewrote this guide around the pixels, mounting and controllers we recommend today. The original 2013 version was built around pixel strip and hardware that has since been replaced.

When you're planning a Christmas display, it's easy to focus on everything going in the yard. But the biggest prop is already there: your house. Outline it, and the house becomes part of the sequence, framing everything you've built in front of it.

Vineyards Lights, Meridian, ID. The rooflines, peaks and garage all become part of the show.

If you want the big picture first (why a mounting system matters and how to pick between seasonal and permanent), start with our house outline primer. This post is the step-by-step design: how to measure, how many pixels you need, how to power them and where the controller goes.

Would you rather have us do the math? Fill out our project design form and we'll send you instructions for sending us one photo of your house and your measurements. We'll put together a recommendation and a complete quote with the controller, mounting, hardware and accessories for your project.

Step 1: Start with a photo

Go outside and take a photo of your house from where your audience will see it, usually the street. You'll sketch your design on this photo and use it to record measurements, where cables will run and where the controller and power supplies will go.

We'll use Nathanial R.'s house as our example throughout. It has 19 separate rooflines, so it's a good example of how a house with complex roof lines can be handled.

Step 2: Measure every run

Get out the ladder and tape measure and record the exact length of every section you want to outline. Write each one on the photo.

Accuracy matters. Every foot you miss is another 4 pixels at 3 inch spacing, which changes your pixel count, your power budget and possibly how many controller outputs you need.

Step 3: Choose seasonal or permanent mounting

Across a whole house, mounting pixels one at a time means a lot of clips, a lot of alignment and a lot of visible black wire. A mounting system lets you build the outline in sections that hold their spacing and aim, snap into a few clips and come down as a unit for repairs.

Want it to come down after Christmas? Use Pixel Pipe. Each aluminum pipe is 7.3 feet long with 88 holes on 1 inch centers, sized for standard 12mm bullet pixel nodes. It's available in black, white or mill-finish grey, mounts with clear, UV-resistant clips that can stay on the house year-round, and rotates in its clips so you can aim the pixels toward your viewing area. Couplers, corners and tees let you follow the roofline.

Want it to stay up? Use PixaTrack. Each track is 6.66 feet long with 80 holes on 1 inch centers and takes 12mm bullet or square-neck nodes. It fully encloses the wiring to protect it from UV and animals, comes in off-white or brown to blend with the house, and is available with front-facing or side/down-facing holes.

Both come as samples, so you can hold one up against your house before you decide.

Step 4: Pick your spacing and count your pixels

Because both systems are drilled on 1 inch centers, you can space pixels at 1, 2, 3 inches or more by skipping holes. Two things set how far apart you can go:

• The wire length between nodes on the pixel string. Our 100-count 12mm node strings reach up to about 3.4 inches between nodes. For wider spacing, our 6 inch strings reach up to about 6.8 inches.
• The look you want. Closer spacing reads as a solid line and gives you more resolution for effects. Wider spacing costs less and gives a more classic bulb-by-bulb look.

The math is simple:

Pixels = run length in inches ÷ spacing in inches
DMX channels = pixels × 3

For Nathanial's house we grouped the 19 measured sections into four continuous runs and used 3 inch spacing:

Run	Length	Pixels (3" spacing)	DMX channels	Watts at full white
Garage front	26 ft	104	312	57
Garage, over the doors	34 ft	136	408	75
Front of house, upper	53 ft	212	636	117
Front of house, lower	31 ft	124	372	68
Total	144 ft	576	1,728	317

At 170 pixels per DMX universe, 576 pixels needs 4 universes. Any current E1.31 pixel controller handles that over a single network cable.

Step 5: Plan your power

Our 12v, 12mm nodes draw about 0.55 watts each at full white (45 milliamps). That's where the watts column above comes from: 576 pixels × 0.55 W = about 317 watts, or roughly 26 amps at 12 volts. Size your power supplies with headroom above that number, since draw varies with temperature, wiring and supply voltage.

The second question is how far the power can travel. As power runs down a string, voltage drops through the LEDs and the wire itself. Our 100-count node strings are designed to run the full 100 nodes with power fed at the start. Past that, plan to inject power. Three of the four runs above are over 100 pixels, so each would get power injection partway along, or be split into two shorter runs fed from separate outputs.

To inject, run heavier-gauge wire (14 AWG is a good start) from the power supply to the injection point and connect it to the power and ground of the string there. The data passes straight through, since each pixel regenerates it. See our guide to wire selection for sizing the injection wire.

Test before it goes on the house. Build a section, set it to full white for 15 to 30 minutes and measure the voltage at the controller output and at the last pixel with a multimeter. A drop of 10 to 20% is usually fine. Much more than that and you'll see dimming or color shift at the end of the run, or random flicker if the voltage falls below what the pixel chips need. Finding that on the ground is a lot easier than finding it on the roof.

Step 6: Place the controller

Look at your photo for where runs start and end. Places where two runs meet, like a garage corner or the peak over a front door, are natural spots to feed two outputs from one location. Current pixel controllers and sequencing software let you reverse a run's direction, so a run can start at either end.

The data signal from a pixel controller output only travels a limited distance to the first pixel, so you have two basic layouts:

• One central controller. An AlphaPix Classic with 4 or 16 outputs, placed somewhere central and close to the runs. It keeps everything in one enclosure, and spare outputs can drive other props in the yard.
• A controller plus long-range receivers. With a Flex system, the controller can sit in the garage and small long-range receivers go near the roofline where the runs start. This is the better fit for large houses, runs that start far apart, or when you want the main controller out of sight.

For Nathanial's four runs and about 317 watts, a single 4-output controller placed near the garage corner would handle the whole outline. Adding props later, or splitting the long runs, is where a 16-output controller or a Flex system with receivers starts to make sense. Our Controller Selection Wizard walks you through the options.

Step 7: Build and test on the ground

One of the biggest advantages of Pixel Pipe and PixaTrack is that you can build each section on the ground, plug it in and test it before it goes up. With connectors between sections, a problem later means unplugging one section, fixing it in the garage and putting it back without disturbing your spacing. With a seasonal install, the sections come down as a unit and go back up next year exactly as they were.

Watch the full process

Our house outline video walks through planning and building an outline with Pixel Pipe and PixaTrack from start to finish:

Let us put it together for you

You don't have to work out every part of the system yourself. Fill out our project design form and we'll send you instructions for sending one photo of your house and your measurements. We'll look at what you're planning and put together a recommendation and a complete quote with the controller, mounting, hardware and accessories you'll need.

Want to see the mounting in person first? Pixel Pipe and PixaTrack samples let you compare colors against your house before choosing a system.

HolidayCoro.com

DMX & LOR Protocols and RS-485 (Legacy Serial Networks Explained)

Legacy technology notice (updated September 2026): This post covers the DMX and Light-O-Rama protocols running over RS-485 serial cable. That is now considered ancient technology. All modern lighting control, including every pixel controller we sell, runs over Ethernet using E1.31.

If you are building or expanding a display today, start with our guide, Where Do I Start When Designing a New RGB Pixel Project. About 80% of our residential customers sequence with xLights, which is free and works with all of our controllers. We have kept this post, which now also includes our former "Understanding the DMX Protocol and the RS-485 Relationship" article, for anyone still running legacy serial hardware.

I'm a firm believer in understanding "why" something does what it does and what effect those systems have on performance and reliability.  It is only when a person understands the underlying systems and processes that the "mystery" of why issues occur can be understood.  One area of confusion I see with customers comes up over and over and that is the relationship that the DMX and LOR protocols have with RS-485.  First, lets start with some basics:

• Both DMX and the LOR controllers use a protocol for communicating between a PC (usually) and a controller (AC or DC) to make lights turn on or off at a specific time.  A protocol is nothing more than a definition of how two systems talk with each other - another example of a protocol would be TCP/IP or even the English language - it is nothing more than a set of rules that both parties/controllers agree on.
• DMX Protocol:  The DMX protocol was defined in the early 1990's by the theatrical lighting community and is codified in a specific standard usually called DMX512 or E1.11.
• LOR Protocol:  The LOR protocol was designed by Dan at Light-o-Rama in the late 1990's.  This protocol is unique to LOR and for the most part is not publicly used by other controller vendors.  The reason this protocol was created instead of using the existing DMX protocol was because of it's need to run very slowly (19,200 kb/s) compared to DMX's 250,000 kb/s as a result of a need to run on cheap, poor quality flat telephone cable (this is why you have a phone jack on an LOR controller.)
• Both DMX and the LOR protocols run "over" RS-485.  RS-485 is a signalling protocol that defines the physical and electrical nature of the way each system will talk with each other.  Examples of this would be the Ethernet standard or how the letters of the English language are written.  RS-485 doesn't concern itself with what protocol is running over RS-485 but simply how the controllers interact at the physical and electrical levels.  This is why you can use a LOR "dongle" and output either the LOR or DMX protocols because the dongle is nothing more than a RS-485 output device - it is the software (LOR S3) that defines the protocol that is going out over the RS-485 connection.

There are some pros and cons to both the LOR and DMX protocols and we've covered those in previous presentations.  What is more important than the protocol (DMX, LOR) is RS-485 - this is where I see the majority of confusion, misunderstanding and problems.  Here are some common questions and answers to issues surrounding RS-485:

• You can't "Tee" or split DMX/LOR signals
• Again, this doesn't have anything to do with DMX or LOR - splitting a signal from an output dongle does have everything to do with RS-485.  On LOR controllers, there are two RJ45 plugs (excluding the one for telephone wire) for CAT5 cable.  You'll notice that there isn't really an "in" and "out" - why?  Because it doesn't matter.  As the signal comes from the output dongle to the first controller, then to the second and so on, all that is happening is that each controller is "tapped" or "tee'd" off a single data line.  Each controller simply listens to all the data on that RS-485 data line and waits for data that indicates that it should do something (dim, shimmer, etc).  This is the exact same with DMX controllers (in most cases) - the difference on DMX controllers being that some of them have XLR plugs which have a different connection for input vs output but in MOST cases, the controller is just connected to the wire.  (Yes there are some repeating/regeneration controllers but that is often the exception than the rule.)
• Have you seen DMX controllers that only have only an input but no output?  Have you wondered if you need to split the signal to each one or have a separate output dongle for each one? 
• Since there really isn't an input and output for the signal in most cases, all you need for a controller to work is to "tee" the controller off of the data line.  That could be that each controller is just manually soldered to each input and then the cable continues on to the next controller or by using a passive CAT5 splitter/tee.  So, if you have a controller that only has an input, it's not a problem - just split the signal outside of the controller as opposed to running the signal into the controller and then back out.  This is the same method we use on most HolidayCoro DMX controllers.
• I hear there is a limit to how many DMX controllers you can hookup to a single DMX output dongle.
• It depends.  Remember here that what really is at play is RS-485, not DMX.  So DMX doesn't limit you at all to how many controllers you can have hooked up to a single dongle - RS-485 limits you.  What are those limits - well it is a number of factors:
• Power output of dongle - The RS-485 standard allows up to 19 volts of power for signal (-7 to +12).  So, the more voltage that is used for the signal output, the better.  This is somewhat like the difference between just yelling at someone a long distance away or using a bull horn - clearly the more powerful and amplified signal using the bull horn will go much feature and be much clearer to the recipient and will also be able to more easily overcome any background noise.  While the RS-485 standard allows up to 19 volts, nearly all USB based devices are limited to the USB voltages - about 5v.  Why does this matter?  Two reasons - noise and power loss - see below for more details.
• Length and gauge of signal cable - Since cable itself induces loss, as your cable length increases or the gauge of the cable rises (see our blog entry on cable sizes and lengths), the overall strength of the signal also drops.  Lower power means there is a lower signal to noise ratio and you start to experience problems.
• Type of cable - When selecting wiring for RGB elements, you have lots of choices out there.  Excluding the gauge of the cable, the other major factor of cable selection is how the cable is constructed.  There are two basic methods - twisted and non-twisted.  Why does this matter?  Twisted pairs of wires inherently does a much better job of rejecting EMI (noise) - this is the reason that all CAT5 cables are designed with twisted pairs of wires.  If you selected a cable (alarm wire, SPT cable, etc) without a twisted pair for the data signal, you risk greater EMI interference over straight cable.
• Number of devices - Each controller exerts a "load" on the RS-485 line.  This basically means that as each new controller is added to the RS-485 line, it "sucks" some of the signal off, reducing the overall voltage on the line.  Once you get too many on the line and the voltage drops too much, the controllers are unable to determine the actual signal from any noise on the line.  So, how many can you put on a line?  It depends the the RS-485 chip used in the controller, some less efficient chips might limit you to 30 controllers, some might limit you to 100+ controllers on a single line.  How can you tell if you have too many controllers on the line?  Checkout this video article that shows about 50+ controllers connected to a single DMX output dongle.  You'll see that the only real way to know where you are pushing up against a limit is if you have the proper diagnostic equipment - namely a scope.  This is why we sell our pocket scope - so you can determine exactly what the RS-485 signal quality looks like.  We recommend this article by Maxim, the company that produces 485 chips if you would like in-depth details.
• Termination - While "technically" all RS-485 connections should be terminated with a resistor, the reality is that it is often not needed and in fact, LOR doesn't even terminate their controllers due to the inherent design of their system (slow speeds and forced bus connections/tapping.)   When and where you need termination mainly varies based on the wiring scheme (serial/bus, long taps, location of output dongle on the line, etc) - the best place for technical details on the do's and dont's of termination is in the Maxim article.  You can also watch our video showing a real world lighting display, over a scope, showing what effects adding or removing a terminator will do to the signal.  Be aware that termination is no free ride and won't fix a bad network design.  Terminators are resistors and as a result, the "suck up" and reduce the level of signal - so while it might clean up the signal, you might end up with too little signal to make a difference.

With all this said, the vast majority of networks are simple and even when improperly constructed with the wrong wire, bad termination, long taps and other errors, RS-485 (and thus DMX and LOR) still continues to work.  Why?  Because RS-485 was designed just for this - to work in environments like factories with bad wiring, lots of EMI and long runs of cable.  When you really need to be concerned about these issues is when you get dozens of controllers, over long lengths of cable and with bad cables or connections.  If you are one of those people, we *highly* recommend getting a scope because without one, you'll only be guessing as to what the quality of your network is or where a problem might exist.

DMX basics

• Where it came from. DMX (DMX512, standardized as ANSI E1.11) was developed in the early 1990s by the United States Institute for Theatre Technology (USITT) as a public standard, so lighting hardware and software from different vendors could work together.
• What it is. DMX is a protocol, a set of rules. It isn't a wiring standard or a physical thing. RS-485 is the "road" DMX traditionally runs on.
• Channels and universes. A DMX universe has 512 channels. Each channel is a level from 0 (off) to 255 (full on). A pixel uses 3 channels (red, green, blue), so one universe holds 170 pixels.
• Speed. DMX runs at 250 kbit/s. A full 512-channel universe takes about 22.7 milliseconds to send, so it refreshes about 44 times per second.
• One line, one universe. Over RS-485, each serial line carries a single universe, which is why large serial displays needed many dongles and cable runs.
• Effects come from software. DMX devices don't generate effects on their own. The sequencing software sends every level change, unlike the LOR protocol, where the controller carries out fades and effects itself.
• DMX over Ethernet. E1.31 (sACN) carries DMX universes over a standard network instead of RS-485, so one network cable can carry hundreds of universes. That is what every modern pixel controller uses today.

I welcome your feedback or suggestions below.

Thanks,
David
HolidayCoro.com