From Trammell Hudson's Projects
The mission of the October First committee is to enable artists, not to dictate art ideas. We want to present our creative collaborators with a menu of proven components and to encourage them to incorporate these items into their designs early in their artistic process.
Additionally, we want the "worker bees" to be able to quickly assemble the art pieces on playa during the first few days of build week and then enjoy the party. We don't want to spend the entire week soldering in a shipping container -- even with flux it is hard to do due to the dust. Common components, connectors and modular design make this easier.
- 1 Playa-proven Hardware
- 2 Common Software platforms
- 3 Robust connectors
- 4 Power Supplies
- 5 Enclosures and Cases
- 6 Structural Components
- 7 Outputs
- 8 Interactivity
- 9 Connectivity
The harsh environment of the Playa provides a difficult testing environment for electrical components. While the power supplies have historically been the most common failure, the compute hardware that drives the outputs and interactive elements must also be very robust.
For 2013 to drive the WS2812 LED strips, we designed boards based on the Teensy 3.1 and multiple bare BeagleBone Blacks running a very early version of LEDscape (using patterns written in processing and UDP to communicate to the four Blacks). The biggest problem that we ran into was instability in the long USB cables required to reach the different parts of the pyramid.
These were reused on the DEX for 2014, although the Molex connectors and old strips were problematic. The other problem is that the micro USB connectors on the teensy boards failed frequently by snapping off, so we can not recommend using them.
The 2014 frontage and Helios used an updated version of the software and a custom BeagleBone Black cape that used the PRU to drive up to 32 of the WS2812 strands. The patterns were written in ??? and communicated to the LEDscape controller with OPC over TCP.
Older Panasonic Toughbooks were used both years for various projects and are suitable if the entire stack is not pre-rendered or requires more CPU than the BeagleBone boards. Multiple CF-30 models were purchased for $200-$300 each.
- BeagleBone Black controllers, with custom capes
Common Software platforms
The LEDscape software is at the bottom level of the stack -- it handles the interface between the real-world components likes LED strips, matrix panels, relays, etc. It receives data from the next layer up over OPC or other protocols, using UDP to gracefully deal with intermitent network failures.
The patterns for the 2013 pyramid were written in Processing. These were mixed in the same process, which required extensive CPU and also required the Toughbook to be tethered to the pyramid for the entire week. Later these patterns were written to a file and a special replay process on the BeagleBone Black allowed the mini-pyramid to run stand-alone and without concern about the CPU usage on the slow Toughbook.
The 2014 frontage used ??? running on a Thinkpad, talking to the LEDscape controller over OPC/TCP. This also required tethering the laptop full-time to the signage. This system had a custom visualization and mixing process -- writing a general one for the various components would be very useful.
One lengthy step with many systems is figuring out which outputs are going to which display elements. An external camera system could be used to identify the 3-space position of the pixels and map them to their coordinates in the display.
All of these displays were non-interactive, so they did not require any outside inputs. Future art projects will need to consider interactivity with the audience and connectivity between other art pieces.
- Expand LEDscape to support:
- OPC over UDP
- Replay of OPC data
- ffmpeg replay, mixing
- Blending from multiple sources
- Write visualization component
- Write 3D pixel calibration system
- Meet with projection mapping experts
Each year we have had problems with having the right set of cables to wire up the projects. If we pick a few to standardize for the few different needs (power and data), we can fill a container with them and be able to more easily adapt to the conditions on the playa.
2013 used Teensy boards connected over their MicroUSB connectors. Over short distances with limited dynamics these worked ok, but over longer distances there were frequent protocol errors that caused the USB port to hang.
In 2014 these were reused on the DEX, but the vibration and stress on the connectors caused all of the MicroUSB jacks to rip off the boards. The jacks are not robust against the dust or pluging,
These are suitable for higher amperage loads and are fairly easy to adapt on the fly, but are not very fast to connect. Sufficient access for tools is important.
Readily available and highly robust, but very low density. Only three conductors (plus shield). Field termination requires soldering, but the lugs are large and easy to work. Can be used for power transmission and single-ended data, or with extra hardware and phantom power for differential data. DMX uses XLR5, although most applications continue to use XLR3.
RJ45 / Cat5
Very cheap and available anywhere, ok density (8 conductors). Pre-made cables are available in any length and color, plus field termination is easy without a soldering iron. Ethernet uses it, which is useful for connecting controllers together up to a few hundred meters.
Thus far they have held up quite well in the dust, despite the small contact area of the pins and the recessed nature of the RJ45. A quick blow with compressed air seems to keep them in good shape. If it becomes an issue, waterproof RJ45 are available.
DMX has a specified RJ45 encoding with two channels per cable, so this is a natural fit for our new LED connectors.
Commonly used in small electronics projects, good density but poor robustness. Limited strain relief makes them subject to stress failures. Available from online sources, but not in stores.
The 2013 LED panels were wired with 6-pin pre-terminated Molex connectors. They are frustrating to disconnect and not widely available. They filled with dust and were subject to pins bending while being connected. Not commonly available in stores, although some autoparts shops might carry them.
These are really neat hermaphroditic connectors -- instead of male/female ends, they can plug into themselves. Not weather sealed, but fairly rugged and high current. Must be soldered and only available from Anderson.
Official Amphenol connectors are incredibly robust, but expensive and not available outside of specific distributors. Adafruit sells a similar hanging inline four-conductor waterproof connector that is much smaller than a XLR. Waterproof Polarized 4-wire cable set ($2.50)
- Screw terminals for power, up to 30 amps
- Cat5 for communication, both ethernet and custom data
- USB where necessary, inside of boxes over short runs that will not be exposed to the dust.
- Support daisy chainable wiring when possible.
- Get Monoprice quote for 1000 ethernet cables in orange and different lengths.
One of the single largest points of failure in the playa projects has been the DC power supplies. Attempts in 2013 to weather proof them lead to limited airflow and failures. We managed to keep the pyramid running by removing all of the covers and exposing the supplies to the elements, which lasted the week, but caused eventual failures due to dust build up on the fans.
One problem with the WS2812 and LED panels is that they are running at +5V. For high power loads very thick wires are required. Running a higher voltage supply and regulating at the point of use would make more supplies available -- there are many +12V supplies for industrial applications that are already weatherized.
- Test sealed +5V supplies, like Meanwell LPV-35-5, a $15, 5V5A supply that is rated to 65C and waterproof.
- Test sealed +12V supplies with point-of-use 12V-5V DC-DC regulators.
Enclosures and Cases
2013 and 2014 both used cheap plastic ammo cases. For fanless systems, these can be sealed and provide a fairly weather proof environment for electronics. With the covers on, however, there is limited airflow and anything with a fan will certainly fail.
Pelican cases and Otterboxes can be modified to provide a truly waterproof system, although the connectors are always an issue. These are also more expensive than the ammo boxes.
Bare boards had a suprisingly low failure rate. We had numerous LEDscape boards running in the dust without any failures.
- Use ammo boxes where possible
- Improve ruggedness of cables; add seals and strain relief
- Follow guidelines in Weatherproof Enclosure Build Tutorial
- Misumi extrusion ($/m ?), need library of brackets
- M3/M4/M5 hardware everywhere
- Avoid screwing to wooden structures -- too much MOOP.
- Pipe and u-bolt clamps
- Incorporate palate rack into structure?
- How to build art pieces in modular ways (easier packing and assembly)?
- No wood!
- Price quote for 15mm and 25mm extrusion in 2m lengths
- Buckets of M3 hardware
2012, 2013 and 2014 all used WS2812 flexible LED strips, in both 30 LED/m and 60 LED/m strips. They have the advantage of being very cheap, have a simple one-wire protocol and are easy to build into large, non-rectilinear structures. The LEDscape hardware can drive very large numbers of them from the a single BeagleBone, making it simple to control.
Unfortunately, all years have had significant number of strip failures, both mechanical and electrical. The flexible PCB is difficult to solder to and prone to failure where the wires attach. The first LED on the strip frequently fails due to static or mis-wiring, causing all other LEDs on the strip to stop functioning.
Jumbotron panels are cheaper than the WS2812 strips, but are harder to drive effectively. The Octoscroller control board can drive up to 64 panels (a 256x256 matrix) from a single BeagleBone Black at 30fps.
These are readily available from China in a range of sizes -- 6-15mm are common -- and are also available in waterproof varieties. The default connector is a 16-pin ribbon cable and not as robust as others, but it does daisy chain easily between adjacent panels.
- Small/Large venue?
- Calibration software?
- Air filtration?
- 512 outputs per channel
- Traditional dimmer packs
- New LEDs with built-in DMX
- Need to write LEDscape firmware to talk DMX
- Normally uses XLR connectors, but we can also route over cat5
- Trigger or turn on other devices
- Useful for AC loads, fog machines, button pushes, etc
- Need to build a cape to handle lots of relays (or a DMX relay driver)
- DC motors
- Steppers motors
- Which are sealed?
- Servitron Six or DMX interface?
- Soft - fabric choices
- Hard - HDPE, acrylic
- Edge lighted materials
- Laser cut separators
- Lasers / pan-tilt stages?
- Tethered Blimps?
- Fog/mist machines?
- WS2812 strips are unreliable. Even in the best of conditions, they have frequent failures.
- Outside LED panels are great if they work with the art.
- Need to consult experts on projection mapping and other topics
Most of the Disorient frontage has been display pre-rendered patterns, although future art pieces might interact with the music and audience. Some ideas that have been discussed:
- Audio inputs from DJ
- Directional microphones for audience
- Kinnect / Depth sensors
- Laser trip wire
- Communication between art pieces
- Discuss interactivity with artists.
- Spec out some robust buttons, knobs, etc.
- Find weather proof microphones, etc.
As we add more pieces to the frontage, art cars and public spaces of the camp, it would be great if they had some common themes and elements. Part of having a common software stack is that it allows us to more easily have them communicate with each other to synchronize patterns and responses.
- Ethernet is best for static pieces
- Ad-hoc wifi networks work great to bridge in art cars, if DPW allows it
- Multi-drop serial can work, but is very low bandwidth.