They requested a single channel, variable speed [1 Hz – 10 Hz] LED flashing driver which could be battery powered and switch about 40 watts of LED light. There were to be two performer-accessible switches: one for power and a second for selecting between constant and flashing output.
Just over 2 weeks later, we delivered about 70 small controllers. They looked like this:
The flash-speed adjustment is inside the enclosure, hidden away from well-meaning but not-to-be-trusted performers. These controllers drove the ‘cube hat’ costumes which were seen at the very end of the show. Apparently the choreographers or directors chose not to use the flashing feature, as the hats glowed constantly.
However, it was fun seeing them live on stage.
Shortly after these controllers were delivered, we learned that they also needed more complicated control equipment. The 8-bit DMX Driven RGB Nodes discussed elsewhere on this site seemed like an ideal fit, so we designed a battery powered system which could receive DMX data (from a costume designer’s lighting console), store it to an SD card, then replay the patterns on command. 4 strings of 42 nodes would be driven and refreshed at about 30 frames per second.
Here’s a photo of the system’s enclosure and bare circuit board, before all the components and wiring harnesses were added:
After these controllers were designed and prototyped, but before they shipped to the customer, we learned that the 8-bit nodes were the wrong form factor for the two costumes. They were nice and bright, but didn’t fit like in the costume like they needed to.
So, the LED vendor suggested using two other products: a ‘smart’ strip containing RGB LEDs and HL1606 control chips (nice for discrete LED control) and a ‘dumb’ strip containing RGB LEDs wired in parallel.
The 1606 controller is an interesting beast, as nicely described by Alan on his website. Each chip uses a pseudo-SPI interface and drives two RGB LEDs. 5 meters of strip includes 160 SMD-5050 LEDs. Each LED can can be set to any of the seven major colors (R,G,B,R+G,R+B,B+G,White), and each LED can also be told to fade between major colors at a specific fade rate. The downside is that the LEDs can’t be set to arbitrary colors outside the major 7. If you want 80% red and 10% blue, you’ll only see it for an instant as the fade progresses.
In this regard, it’s not a terribly useful controller for our purposes, which is displaying live content. But, it was available in the time we had to work. And that’s what engineering as all about.
The costume designers deemed the form factor appropriate and the 7-color limitation acceptable, so we moved ahead.
Pity our regular 8-bit nodes didn’t fit properly.
In any case, the green cube controller from above was reworked to drive 2 strings of HL1606 LEDs. Each string could have up to 256 LEDs, consuming an entire universe of 512 channels. As each channel’s level is increased, the LED color cycles between red, redgreen, green, greenblue, blue, bluered and white.
For the costume based on the ‘dumb’ RGB strips, the designers requested that 16 discrete RGB outputs be available. So, we (very very quickly) designed and produced a much larger controller. 48 output drivers / 3 drivers per strip = 16 LED strips total. Controlled by 48 consecutive DMX channels. Due to the extremely tight time frame we worked in, the output stage is massively over-engineered. 5A switches per color, per output. But it worked beautifully.
Again, regular DMX data can be captured at 30 frames per second, is stored to permanent memory, and then plays / loops on cue.
This controller drove several hundred LEDs in Taboo’s suit.
The smart strip LEDs and controller were sewn into apl.de.ap’s costume. During the show, they ran a series of color-changing ‘spectrum analyzer’ type effects. Sadly, they were somewhat overpowered by the other stage lighting, and only visible if you looked quite closely. Thanks to GrandMA programmer Jerry McVay for some amazing work.
Wouldn’t it have been easier to drive the suit live with wireless DMX? Yes, absolutely. However, it wasn’t allowed inside the venue, probably due to hundreds and hundreds of other transceiver sets competing for the same radio space. I’d hate to be the RF guy charged with mapping the spectrum and making sure everyone’s bits played nicely together.
So at the beginning of the halftime show, the head costume technician received a cue from the broadcast truck 22.5 seconds before the performers took the stage. On that cue, a rigger high up in the steel of Cowboy stadium’s roof switched on both playback controllers. Each suit flashed a quick ‘hello world’ to confirm its operation, and the Peas descended from the ceiling.
Watching your small company’s custom-designed equipment run flawlessly in front of 110,000 live fans, plus another 100 million television viewers, is a massively humbling experience.
Thanks to those who worked with us through the last month. The costume technicians and seamstress crew did amazing work when faced with monumental deadlines. You know who you are.