Time Never Moves Slowly With This Clock

A clock is by its very nature a device for measuring time, and thus it moves forward at a constant rate. But how about in a theatrical setting, where time runs at the whim of the director? For the stage, a clock with more flexibility is required. To this endeavor [Playful Technology] has you covered, with a larger than life stage clock whose hands are independently controllable by DMX.

Behind the clock is a very unusual part, not the modified clock mechanism one might expect, but a dual stepper motor with a concentric shaft. This is driven by an Arduino with a stepper driver shield more familiar from the world of 3D printers, and an RS485 interface for DMX interfacing. The hands are built in OpenSCAD, and 3D printed to be an interference fit on the shafts. The DMX controller software has a handy rotating knob style interface, allowing easy hand manipulation.

You can see the results in the video below, complete with an exhaustive dissection of the Arduino code. Meanwhile DMX is itself a fascinating subject, and in the past we’ve taken a deep dive into RS485.

Continue reading “Time Never Moves Slowly With This Clock”

Stage Lighting Hack Keeps La Bohème From Becoming A Dumpster Fire

With all due respect to the Utah Opera’s production of La bohème, we just couldn’t resist poking a little fun at master electrician [David Smith]’s quick lighting hack for the opera. And who knew an opera from 1896 would need a garbage can fire? Live and learn.

In what appears to be a case of “The show must go on,” [David] was called on to improve an existing fire effect for one scene in the opera, which was reportedly a bit “artificial and distracting.” This is a pretty common problem in live productions of all types; it’s easy to throw light at a problem, but it’s often hard to make it both convincing and unobtrusive. Luckily, he had both the time to come up with something, and a kit full of goodies to make it happen. A balled-up strip of Neopixels provided the light, with an Arduino running some simple code to randomize the intensity and color of the RGBs. [David] stuck with the warm white, red, and green colors, to keep the color temperature about right for a fire, and drove the LEDs with a couple of MOSFETs that he keeps in his kit to fix busted dimmer packs.

The overall effect worked well, but the holes knocked in the side of the greatly abused garbage can let too much light out, making the effect distracting on stage. The remedy was simple: a cylinder of printer paper surrounding the LED tape. The paper not only acted as a diffuser but held the tape in place inside the can. The electrical crew ran two circuits to the can — one to keep the Arduino running throughout the show, and one to power the LED tape. The former made sure the audience didn’t see the microcontroller boot sequence, and the latter gave the electrician a way to control the effect from the dimmer console. The brief video below shows it in action during a rehearsal.

Hats off to [David] and the whole crew for the stagecraft heroics and for getting this thrown together so quickly.

Continue reading “Stage Lighting Hack Keeps La Bohème From Becoming A Dumpster Fire”

Learn DMX512 Basics

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.

Continue reading “Learn DMX512 Basics”

Developing A Power Over Ethernet Stack Light

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.

An early Arduino-based prototype.

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.

Ljusmaskinen Takes The Rave To The Streets (Eventually)

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!

Control Lighting Effects Without Programming

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)]

LED-ifying A Guitar, Part Two

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.