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Controlling lights with your own laptop

(Under construction by Daan)

Introduction

This is a guide on how to control lights on the go, using your own laptop, outside of the blackbox.

In this guide, we will use a device called a DMX interface to communicate with an LED light or dimmerpak, using the free software called QLC+. We will need to download a driver for the DMX interface, and install a fixture profile for the light you wish to use. I will guide you through these simple steps


1. Materials needed

We will need a couple of ingredients for this to work. You should be able to find all of these in one of HKU’s uitleens. You'll need a:
-

  • Working laptop or computer
    -
  • If you’re on Mac, a usb-c dongle to connect the USB device
    -
  • DMX interface (ENTTEC USB Pro MK1 or 2)
    -
  • 5-pin DMX cable
    -
  • LED light with DMX input (or a dimmerpack with DMX input + a halogen light)

2. DMX interface & driver

Before connecting the DMX interface, we need to install the driver for it. The company that makes the interface is called ENTTEC, and they also make their own light control software. We need to install this software so our computer can communicate with the interface. The software is called EMU, you can download it here.
You need to make an account to download the file (any email will work, no verification needed). If you a re opposed to this, a blackbox employee can give you the file if you want.

After installing the driver, we can now start connecting our devices. The DMX interface we connect with a USB cable to our computer, and using a DMX cable we connect the DMX interface to our light. Pay extra attention that you connect the cable to the 'DMX OUT' of the interface to the 'DMX IN' of the light. See pictures below.

Laptop -> (USB-C dongle ->) DMX interface -> LED light

IMG_6055.jpeg

3. DMX interface in QLC+

The software we use to control lights in the blackbox is QLC+ (among other softwares, for different use cases). You can download QLC+ here. When you open QLC, this window will pop up:

image.png

Click on Q Light Controller Plus. An empty QLC file will pop up.

Screenshot 2025-11-25 at 15.20.31.png

In the bottom we see a bar with several options, including fixtures, functions, shows, etc. The first step is to check if QLC is recognising our DMX interface. To do this, in the bottom bar, navigate to the inputs/outputs tab.

Screenshot 2025-11-25 at 15.27.18.png

Here we should see our DMX USB Pro interface. If it's not yet visible for you and the output box is not checked like in the picture above, make sure your DMX interface is connected. If it is, and it's not showing up, in the list under 'plugin', click DMX USB in the list and then press this icon:

Screenshot 2025-11-25 at 15.55.21.png  Screenshot 2025-11-25 at 15.53.04.png

The list should now refresh and the DMX interface should become visible and connected.

After you've confirmed this, navigate back to the 'Fixtures' tab.

4. Configuring our light

Before we can communicate with our light, we need to understand how our light is configured. The settings we enter in our light need to correspond with how we set our light in QLC. For this there are two terms to understand. Channel Mode, and DMX Address. We'll start with Channel Mode.

Channel Mode

To understand what a light's channel mode is, it's a good idea to look up your light in the Open Fixture Library. Once in the library, look up your light, which in my case is a ColorSource PAR Deep Blue by ETC. 

Screenshot 2025-12-16 at 13.03.01.pngScreenshot 2025-12-16 at 13.04.28.png

This page gives an overview of the different channel modes your light can be programmed in. Each channel mode gives us access to a different set of parameters to edit, like intensity, red, green, blue, or strobe. Use the small buttons on your light to figure out which channel mode your light is set to (you might have to keep the 'mode' button pressed for a couple of seconds to acces this menu, depending on the light you're using).

IMG_6057.jpeg

My light is telling me that it's set to '5ch' mode. Looking back at the Open Fixture Library, I can see that the 5 Channel mode gives me access to:

  1. Intensity
  2. Red
  3. Green
  4. Indigo (Blue)
  5. Strobe

This channel mode is fine for now, as it gives me access to a lot of different parameters. It's import to note the order that the parameters are listed in. This has to do with the DMX Address of the light.

DMX Address

Each light can be assigned its own DMX address. Think of the DMX address as the lights house number. We can send a letter to this address, and the letter wil contain a command to turn on for example. My light is set to number 21, which can be found on the lights display (make sure the light is set to DMX mode which displays a number, like in the image below, not the standalone mode which displays something like P:01 or similar)

image.jpeg

By knowing the lights address, we can send a command to this address. This command is a value, usually ranging from 0 to 255. If we send '0' to address number 21, we are sending a value of zero to the first parameter, which in case of the 5 Channel mode, is 'Intensity'. By sending it a value of 0, it means the light is turned all the way off. By sending it a value of 255, the light is turned all the way on. How to send values to different channels in QLC+, we'll get to in a bit. First, we need to input the light's parameters into QLC+, by creating a fixture profile.

5. Adding a fixture profile to QLC+

Going back to QLC+, look in the bottom bar where we also found inputs/outputs, but this time click on the 'Fixtures' tab.

Screenshot 2025-12-16 at 15.23.48.png

Press the green + button. This will open up the Add Fixture menu:

Screenshot 2025-12-16 at 15.26.25.png

In this menu, we can look for the light that we're using. As you can see, there are a lot of brands already listed. In my case, I navigated to ETC, and then found the ColorSource PAR. Find the light that you're using, and click on it.

On the right side of this menu, we now see the tab 'Fixture Properties'. It's important that the settings that we input here, correspond to the settings that were input into the light. So, my light was set to 5 Channel mode, and its DMX address was 21. Make sure these settings correspond, otherwise we end up sending values to the wrong addresses (making your light blue instead of red for example, or your light not turning on at all). Press OK, and then we should see our light in our list of fixtures.

Screenshot 2025-12-16 at 15.43.22.png

6. Controlling lights!

Now finally onto actually controlling lights. To see if we if we set up everything correctly, in the bottom bar, navigate to the  'Simple Desk'.

Screenshot 2025-12-16 at 15.45.34.png

Here we see a representation of what DMX addresses are in use. Channels 21 - 25 have been set with the Intensity, Red, Green, Blue, and Strobe parameters, dictated by the way the 5-channel mode is setup. Turn up the slider with the lightbulb; this will turn the light on, but, we can't see anything yet. This is because the light was turned on for a certain amount, but we aren't outputting any color yet. Use the sliders to output a color.

Screenshot 2026-01-12 at 14.46.27.png

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If we've done everything correctly, the light should now turn on! Please note that operating QLC+ from the Simple Desk will not give you access to all the functionalities that QLC+ has to offer. If you're looking for an overview of some of QLC+'s other features, check out this video tutorial.

Is the light still not working for you? Check if:

  • Your light is receiving power
  • All DMX and USB cables are properly plugged in
  • Your DMX interface is still listed and connected in the Input/Output tab in QLC+
  • Your DMX address and channel mode are the same between the light and QLC+

Light still not working? Please feel free to contact a blackbox employee!

More information on how to control lights in QLC+:

Daisy chaining

Dimmer packs

Isadora

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