If you’ve done anything with modern lighting effects, you’ve probably heard of DMX, also known as DMX512. Ever wonder what’s really happening under the hood? If so, then you should have a look at [EEForEveryone’s] video on the topic, which you can see below.
At the core, the DMX512 uses RS485, but adds software layers and features. The video uses the OSI model to show how the system works.
A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).
Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.
He decided to take the scenic route and designed his own custom PCB that combines an Ethernet interface, PoE hardware, and the ESP32 into one compact unit. It’s no great secret that it only takes a few extra components to plug the ESP32 into the network rather than relying on WiFi, but it’s still not something we see done very often by hobbyists. Rarer still is seeing somebody roll their own PoE solution, but thanks to the in-depth documentation [Tyler] has provided for his circuit, that may change in the future.
On the software side [Tyler] has developed a firmware for the ESP32 that supports both Art-Net and RDM protocols, which are subsets of the larger DMX protocol. That means the controller should be compatible with existing software designed for controlling theatrical lighting systems. If you’d rather take a more direct approach, the firmware also sports a web interface and simple HTTP API to provide some additional flexibility.
While it’s exceptionally impressive, not everyone will need such a robust solution. If you just want a quick and easy way to fire up your stack light, a USB controlled relay and some Python can get you where you need to go.
When humanity comes out the other side of this pandemic there will be a mountain of awesome projects to show off in person. For instance, this backpack mounted DMX lighting was built to be worn as a mobile rave rig by Swedish hacker [Tim Gremalm]. In-person raves aren’t happening right now but that just means there’s time to add waaaaay to many features to this thing until lockdowns become a thing of the past.
The frame holding the lighting integrates into this backpack and we assume that’s where the battery is stored. The Y-shaped masts hold four PAR lights. Incidentally, that mean parabolic aluminized reflectors, which are commonly used for stage lighting, but in this case the halogen bulbs have been torn out for a trio of 4 W RGBW LEDs. The yellow rectangles are 10 W Chip-on-Board LED panels that serve as strobe lights.
But merely having the lights does not make it a Rave — this party needs both music and a way to synchronize the lighting effects with it. The music part was already built and used at the West Pride Gothenburg festival (the second largest in Sweden after Stockholm) five years ago. That project, called Festmaskinen, works in conjunction with Ljusmaskinen (the Light Machine). So two people carry the rave on their backs, one with music, the other with the lighting, now that’s a party!
The light controller board uses a set of four Arduino Nano boards along with four voltage regulators to provide control to each of the PAR lights. All of it is stitched together by control from a DMX input board which also controls the COBs. (In this image the DMX board is hidden below the light control board.) Of course you need something that can process the audio and turn it into DMX512 to bring those lighting animations to life and for that he reached for a Raspberry Pi.
[Tim] has a quick demo of the rig at work which we’ve embedded below. What we’re missing is seeing how the top-heavy structure handles when worn as a backpack. Hopefully he’ll be able to get out of his low-ceilinged home and let the stage lights fly before too long!
Working in a theater or night club often requires a specialized set of technical skills that you might not instantly think about. Sure, the audio system needs to be set up and managed but the lighting system is often actively managed as well. For simple setups, this is usually not too difficult to learn. With more complicated systems you will need to get elbow-deep into some software. With [trackme518]’s latest tool, though, you will only need to be able to edit video.
Sure, this sounds like just trading one piece of software for another, but it’s more likely that professionals working in lighting will already know how to edit video rather than know programming or complicated proprietary lighting software. All you have to do to control a set of lights is to create a video, or use an existing one, and the lighting system will mimic the video on its own. If you do know programming, though, it’s written in Processing Java so changes aren’t too difficult to make.
The software (available on the project’s GitHub page) will also work outside of a professional environment, as well. It’s set up to work with DMX systems as well as LED strips so you could use it to run a large LED display board using only an input video as control. You could even use it to run the display on your guitar.
Photo courtesy of Rob Sinclair (Gribiche) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)]
An electric guitar is all about stage presence. Need to be cooler than a single guitar? No problem — there are double neck guitars. Need to be cooler than that? No problem, the guy from Cheap Trick has a five-neck guitar. Need to be cooler than that? Robbie Robertson played a guitar with an extra mandolin neck on The Last Waltz. Where do you go from there? Obviously, the solution is putting a TV in your guitar with a boatload of individually addressable LEDs in a guitar. That’s what [Englandsaurus] is doing, and the build thread is now getting into how to turn a bunch of LEDs into a display.
In the first installment of this build thread, [Englandsaurus] went over the construction of the guitar itself and how a hundred individually addressable RGB LEDs were installed inside two pieces of plexiglass. When the guitar is displaying white at full brightness, the power draw is 500 W. This, in itself, is remarkable; no sane person would ever plug a guitar into a 500 W amp, and even 100 Watts is just too damn loud. There’s more power going to the lights here than the amplifier, and that’s awesome.
Simply sticking LEDs in a guitar does not a build log make, so how are these pixels addressed? How do you make a display out of a bunch of LEDs? This is a hell of a problem, but with Artnet and Resolume Arena 6 these pixels can be mapped into a cartesian grid, and from there it’s just putting video on the guitar.
While the first installment of this build is great and shows you how far you can take electronics in a guitar, this installment is a great demo of turning a bunch of LEDs into a display, something that applies to more than just a gigantic glowey guitar.
DMX512 is the standard for theatrical lighting, and it’s best described as, ‘MIDI for lights’. It’s been around since the 80s, and in the decades since it’s been used, abused, and shoved into just about everything imaginable.
For this week’s Hack Chat, we’re talking all about DMX512. What is DMX512? How does it work? What can you control with DMX512? What Open Source projects use it? There’s a wealth of information out there, and a lot of very cool tricks you can pull with this ubiquitous lighting protocol.
Our guest for this week’s Hack Chat is [Martin Searancke], owner of Dream Solutions Ltd. [Martin] was contacted early on in the development of Coca-Cola’s impressive 3D Times Square advertisement to see if Dream Solution’s LightFactory software could be used to drive this 3D screen. This software has pixel mapping and media playback capabilities and was used for the prototypes for the project. A subset of this product made it into the final installation, and is now driving a gargantuan display above Times Square in New York City.
This is a community Hack Chat, and of course we’re taking questions from the community. If you have a question you’d like to ask [Martin], add it to the discussion sheet.
Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. Our Hack Chats usually take place at noon, Pacific time on Friday, but this week is different. [Martin] is in New Zealand, so this Hack Chat is happening at 2pm Pacific, Friday, October 27th. Is that too hard for you? Here’s a time zone converter!
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io.
You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.
We’re also looking for new Hack Chat hosts! If you’ve built something cool, you’re working on an interesting project, or you’re about to introduce a really cool product, hit us up! Email our wonderful community managers, and we’ll see if we can slot you in.
For a few years now I’ve been developing an interactive army of delta robots. This ongoing project is fueled by my desire to control many mechanical extremities like an extension of my body (I’m assuming I’m not the only one who fantasizes about robots here).
Since my army doesn’t have a practical application… other than producing pretty light patterns and making the user feel extremely cool for a minute, I guess you’d call it art. In the past I’ve held a Kickstarter to fund the production of my art which I can now happily show at cool events with interesting people; Maker Faire being one of them.
Last year, for our debut at the big Bay Area Maker Faire, my collaborator, [Mark], and I displayed a smaller sampling of 30 robots for our installation. We also decided to create an interactive aspect for others to experience. After the end of our crowdfunding period last March, we had a little over a month to do any development before the big event, so our options were slim. The easy solution was to jam our delta code into the hand tracking demo which comes with the Xbox Kinect’s Open NI within Processing. This was cool enough to exhibit, but we hadn’t really anticipated how it would go over in an environment as densely packed as the dark room at Maker Faire.
We should have known better. Both of us were aware that there would be many, many children… all with micro hands to confuse and bewilder the Kinect, but we did it anyway. Our only resolve was to implement the feature that would force the Kinect to track one hand at a time, only after being waved at in a very particular fashion. After needing to explain this stipulation to every person who stopped by our booth over the course of the weekend, we decided never to use the Kinect for crowds ever again; lesson learned.
Over the past year since that experience, we’ve tripled the size of the installation and brainstormed some better demo ideas. As of now, the robots are all individually addressable over an RS485 bus, and we use the DMX protocol over a CAT5 cable to send commands. If you aren’t familiar with it, DMX is used in show production to control stage lighting… to which there is a super neat and free application called QLC+ that allows you to effectively orchestrate the motion and color of many individual light units; perfect for our cause.
Functionally, each of the 84 delta robots in the installation believes that it is a stage light (robots with identity issues). We mapped the X and Y axis of the end effector to the existing pan and tilt values, and the z axis to the beam focus value. The RGB of the LED mounted in the end effector of each delta maps directly to the RGB value of the stage light.
By using the sliders in the QLC+ GUI, I could select groups of robots and create presets for position and color. This was great, someone like me who doesn’t really write a lot of code could whip up impressive choreography with little sweat. Additionally, the program comes with a nice visualizer, where you can layout virtual nodes and view your effects as you develop them.
This is the layout of our installation mapped in QLC+. The teal and purple sliders around each light represent pan and tilt (or in our case X and Y):
Lighting control was an interesting solution. Having autonomous robots this year changed how people responded to them, as they were less like an army you’d command and more of a hypnotic field of glowing grass.
[Mark] and I are considering picking up some flex sensors and maybe playing with the Leap or an EEG headset as a means to reintroduce the interactive aspect. Bottom line, I have this cool new toy that I can’t wait to play with over the summer!
