Let’s take a look at the DMX-2900, one of the decoders that GLLS offers for use with our Vivid Pixel products.

What is it?

It is a DMX to SPI decoder, but it was created with a very specific purpose and some might not be aware of its advantages.

This decoder can be applied normally as an SPI decoder, just as the LT-1809-5A for example. It receives the DMX input signal from a DMX controller and decodes it into SPI signal that our Vivid Pixel fixtures understand.


Using your DMX controller combined with a DMX-2900 decoder, you can control LED NeonFlex Vivid Pixel, changing each channel individually, dimming from 0-100%, and creating various chasing color effects.

Advantages of the DMX-2900

This device also has the power of combining multiple pixel modules in one unified length, in different configurations. For example: A Vivid Wave Pixel RGBW will normally require 4 channels per cutting unit (per pixel).

Using the DMX-2900 you can reduce the numbers of channels necessary by grouping pixels. There is a number of grouping combinations that can be made, ranging from pairs of pixels to controlling the entire fixture as one single color at a time. You can choose your pixel grouping configuration by setting dip switches P6 to P9 according to the chart below.


Take as example the Vivid Pixel fixture shown below. This fixture requires the use of 32 DMX channels of your controller.

Let’s say you don’t have those 32 DMX channels available and your application allows you to work with longer pixels. Using the DMX-2900 decoder, every 2 cutting units can be grouped simulating one single pixel by setting the dip switches to option “2 Px”.


With this setting, the fixture will act as if every 2 pixels are one, and the same run length can now be controlled using only 16 DMX channels.


This application is particularly useful for projects that require the fixture to change as one unified length. In that case, individually programing pixels will require an immense number of channels, and consequently a powerful, expensive controller. We created the 2900 to read the first 1 to 4 channels and continue that input to the rest of the fixture.

Using a regular DMX to SPI decoder, even if you decide to set one sin


gle color for the entire fixture, you need to make use of every channel individually. With the DMX-2900, the whole fixture can be grouped as one long pixel, allowing you to spend only 3 channels (RGB), or 4 channels (RGBW) of your controller.

Let’s take a look at this example:

The length of one Vivid Wave cutting unit is 3.28 inches. Take a 65.6ft run of this fixture, and you have 240 cutting units (pixels) available to create chasing effects. Every cutting unit needs 4 channels, so that would require 960 channels of control.

240 pixels * 4 channels per pixel = 960 DMX channels

That means the capacity of your controller and decoder would have to be at least 2 DMX universes (1 universe=512 channels) using a regular decoder.

With the DMX-2900, creating fading effects (color changing) would require only 4 channels, if you select the option “All”.

Those features make the DMX-2900 a very versatile device, not only decoding DMX to SPI for pixel chasing effects, but also creating more possibilities when the number of channels available is more limited.

Installation and Configuration

All the functions –  either using the DMX-2900 for pixel chasing effects, or single color fading transitions by grouping pixels, DMX addresses and number of channels per pixel – can be chosen by setting up dip switches. Be aware that the DMX-2900 is always in testing mode if it is not receiving a DMX input signal.

When installing the DMX-2900, read the specification sheets of all fixtures and accessories being used to ensure compatibility and proper functionality.

We created 2 reference wiring diagrams to help on the installation of our Vivid Pixel products:

For more information on decoders and GLLS product line, take a look at our documentation page.

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