Synchronized Light Displays

A straightforward approach for synchronizing Christmas lights to music.

Inspiration strikes — During the Christmas and Halloween seasons while watching random videos, you may have come across a crazy looking house with lights blinking and flashing synchronized to music. If you thought to yourself, "Wow! I would love to do that to my house," then this article is for you. With a little patience, this seizure-inducing fantasy can be yours, thanks to many off-the-shelf solutions available to illumination enthusiasts. I must warn you, however, if your neighbors or wife are not agreeable to flashing lights, hours of programming, and potentially hundreds of holiday revelers, then this may be your last chance to step away from an obsessive hobby. At the beginning, ask yourself what your goal is and work towards that. This will help you budget your time, money, and sanity accordingly.

In this article, I will be focusing on Light-O-Rama products, which is what I got started with. I initially chose the Light-O-Rama solution because this hobby can be very complex, and Light-O-Rama provides a straightforward approach to synchronizing lights that got me up and running in a short amount of time. I will also show how Light-O-Rama is compatible with different brands, allowing you to mix in other products so your light show can grow in scale and complexity.

Basic System Overview

From a system level, there are several components that make up a Light-O-Rama setup. Figure 1 shows the typical light system. The general concept of the light display is that you have a PC at the heart of the system that sends out signals to light controllers to turn channels on and off so the lights blink on and off as programmed in the sequence. Each channel is an individually controlled element in the display.

FIGURE 1. Typical light display configuration using Light-O-Rama controllers.

The PC runs Light-O-Rama’s S3 software. The computer runs scheduled shows; each show contains sequences, and each sequence includes a song (.wav or .mp3) and commands that are sent to the light controllers to turn the light channels on and off based on timings.

The PC connects via an RS-485 converter (USB-to-serial) to a network of Light-O-Rama controllers. The controllers connect to the RS-485 converter using a CAT5 cable, and then can be daisy-chained to each other using CAT5 cables.

Light-O-Rama has a wide variety of light controllers. The most common is the CTB16PC (shown with its case open in Figure 2). These can be bought in kit form or fully assembled, and there are commercial grade versions, as well. The controller will plug into a power source and provide power to individual channels. The CTB16PC has 16 channels represented by 16 AC plugs coming out the bottom. Each of these plugs represents an individually controlled channel in the display.

FIGURE 2. Light-O-Rama CTB16PC light controller.

A string of lights plugged into the channel will be turned on and off based on the programming in the sequence. So, one channel may be the lights around a window, another channel may control the lights on a wreath, etc.

This solution requires large amounts of extension cords (one per channel, plus for the controllers themselves). Making your own extension cords is easy using vampire plugs and SPT wire. This DIY method is cheaper than store-bought versions and is a great way to get custom length extension cords.

For audio, most people will connect an FM transmitter or speakers to the audio out port of the PC. Many build their own transmitters from kits; others purchase transmitters online. The quality of transmitters varies greatly, so this is an area you will want to do your homework in.

For the past few years, the EDM kit has been a popular choice. People visiting the display will drive up, tune their radio to a specified frequency, and listen to the music while admiring your lights from the comfort of
their car. This method also has the advantage of not blasting loud music which tends to disturb neighbors.

The downside is you may get dozens of cars parked in front of your house, which will probably still annoy your neighbors (even the nice ones).

Light-O-Rama 3 Software

Software is needed to program light sequences and to run the show. Light-O-Rama software operates in two modes:

1) A software development kit for designing your light display and programming sequences.

Light-O-Rama provides a Sequence Editor that helps you take a song and synchronize it to lights. First, the software has built-in wizards that will automatically find the beat of the music and also automatically create timings that you can program to. You have the option of just tapping along with the music — then your tapping is converted into a timing grid. Since each sequence can have multiple timing grids, you can use multiple sets of timings to get the best result.

Using the Sequence Editor is much like using a spreadsheet (see Figure 3). The columns represent the timings and the rows represent the channels. You color in the cells to specify if you want the lights to be on, fade-on, fade-off, shimmer, or twinkle.

FIGURE 3. Screenshot of Light-O-Rama's S3 Sequence Editor.

There is a definite art and a learning curve to sequencing songs, so plan to devote significant time to it. This is actually my favorite part, and I have online tutorials posted on YouTube that may be useful to you.
The S3 software also provides a visualizer that simulates how your display will look when programmed, without having to hang a single strand of lights. This way, you can develop all of your sequences in advance of putting the lights up.

2) Software that executes your light display schedule.

You configure a schedule that allows you to create an appointment for a show to start at a certain time and end at a certain time. A schedule can run the same show over and over, or run a variety of different shows that you create.

Recall that each show contains sequences. The shows allow you to specify sequences that will start and end your show, and a list of sequences that loop until it is time to end the show. You can even have sequences that run in the background (Figure 4).

FIGURE 4. Schedules contain shows that contain sequences that contain channels.

Currently, Light-O-Rama software only runs on PCs. System requirements grow as your display grows. Typically, running the show does not take a very beefy computer, but you may want some more processing power when programming the sequences and running the visualizer. Often, you will see people program their sequences on one computer, then run the show from a different one. In my display, I run the show using an Acer netbook with very little processing power.

The Creative Process

Synchronized lights is a great project for people that like to tinker. You do both hardware and software, and it’s a project that can be done year round. This hobby does take considerable time, however.

1) First, plan out your display. This is usually done after binge-buying Christmas lights in post-holiday sales. Figure out where everything will go and what needs to be returned to the store. Creating a light display around a theme produces good results. This step usually takes the form of a picture with lots of notes (Figure 5).

FIGURE 5. Planning where everything will go.

2) Create a channel configuration. Here, you configure what controllers you are going to use, what lights will be hooked up to each channel, and configure the visualizer. You will store the channel configuration Sequence Editor, export it to a file, and use it for each sequence. Each year, you will update your channel configuration, so you want to do a good job since you will import this configuration into each sequence you do. Figure 6 shows my notes on mapping elements in my display to channels in my configuration.

FIGURE 6. Notes mapping display elements to channel configurations.

3) Create a library of effects. Using your channel configuration, create a library of effects that you can copy/paste into sequences. This is a personal and creative process, but having a wave left-to-right and right-to-left is a great place to start. This is an optional step, but will make each song much easier to sequence.

4) For each song, you need to get a timing grid. You can use the built-in beat wizard, tapper wizard, and VU wizard to create timing grids. Even with the wizards, you will need to plan substantial time for each song because moving timings around to get it just right will take a while.

5) For each song, you need to program the lights. This is the super fun part. Here, you decide what each channel will do, when it turns on, when it fades, etc. Having the effects library to pull from (step 3) will greatly speed up this step.

Making It Interactive

Normally, when people think about a light display, they think of the lights and sometimes the music, but there is another fun element that can be added: interaction. The Light-O-Rama controllers take a daughtercard, or you can buy an Input Pup that allows you to let people interact with your light show.

The Input Pup works off of simple circuits that — when closed — kick off a specified sequence. This can be used to rig a big red button that kicks off the show, let users pick the next song, or (with some creativity) be
used to turn your light show into a video game that people can play.

If the Input Pup is employed, then it is assigned a unique ID on your Light-O-Rama network just like the controllers (refer to Figure 7).

FIGURE 7. Light-O-Rama Input Pup used to trigger interactive events.

Making it RGB (Color Changing)

The big thing in light displays right now are RGB lights. These are color changing lights where you can set the lights to any color you can create by mixing red, green, and blue.

RGB lights are much harder to deploy than regular strings of lights. You can buy a prepackaged solution from Light-O-Rama, or you can purchase lights and controllers from China or small vendors. The latter solution requires some decisions and some homework to be successful.

There are two main types of RGB lights:

1) Pixels – Each light bulb can be independently controlled. Each bulb contains a microcontroller that watches for instructions and passes data on to the next bulb. These are often used on megatrees or matrixes, and can even display text and images.

2) Dumb – All the bulbs are controlled together. You can set them to any color, but they all change in unison.

What makes the addition of RGB lights challenging is the number of options available. The best approach for making decisions is deciding on pixels vs. dumb, voltage (12 or five volts), type of lights (bulbs, strips, etc.), and topology. Based on those options, you then decide on which controller solution works best for your needs (Figure 8).

FIGURE 8. RGB "dumb" strip.

Light-O-Rama provides an off-the-shelf solution of RGB controllers and lights that sit on your Light-O-Rama network. They also offer their SuperStar software to make programming them easier. For those wanting to do it themselves or to have more options, there are many other RGB light controllers on the market. Most RGB light controllers speak DMX and do not use the Light-O-Rama protocol, but Light-O-Rama software and hardware both speak DMX. This means that you can add non-Light-O-Rama controllers and still use the S3 software to program and control everything.

Figure 9 shows how you can have multiple light networks connected to your controlling computer. Here, I left the existing Light-O-Rama network in place and added a DMX interface to speak to the RGB controllers. This is a common configuration since many light displays will have a mix of RGB and non-RGB lights.

FIGURE 9. Light-O-Rama/DMX hybrid configuration."

The DMX interface could be multiple DMX interfaces. One common interface is E.131 which is a DMX over Ethernet protocol, and the PC and RGB controllers speak to each other using IP over Ethernet. Another popular interface is using an Enttec Pro dongle that connects to the PC via USB, and then speaks raw DMX to RGB controllers behind it. Again, there are other choices and some research is needed to make sure you find the best solution for your configuration.

RGB lights have very specific power requirements. RGB lights are DC powered, so voltage drop is a constant concern. Often, power injection into the lights or signal repeaters are needed to make sure the RGB lights get the needed power and data to operate as expected.

Again, there are many solutions out there, so it requires some tinkering to get it right. If the Light-O-Rama solution is used, then these concerns are already addressed since you get the controller with the RGB lights as a packaged solution.

Conclusion

All of the above can sound pretty complex and challenging. However, while time-consuming, there are enough resources and products out there that make putting together that seizure-inducing light show a straightforward effort. The hobby keeps you engaged as you sequence more and more songs and incorporate new technology. If this is something that is interesting to you, I leave you with one tip of advice: start early. NV

Light-O-Rama offers sequences for sale on their website, but there is also an active Christmas Light community where people freely share their sequences. Everyone’s display configuration is different, but with some copying/pasting and some gentle massaging, you can apply one of these pre-programmed sequences to your display vs. programming your own.