The Light Grid
April 2007 - completed
My friends and I used to throw warehouse parties at a place called The Fake House in West Philadelphia. It was recently torn down after decades as a brick tree house for a rotating group of friendly anarchists. I filmed my senior thesis film project there and got to know Dan some of the other folks that ran it, and they were kind enough to let us throw parties of ever-increasing complexity there.
The third one was Party Party, with an elaborate backstory about harnessing "party energy" with a "party capacitor", which was constructed by my friend Jule Maurer of Maurer Welding, and contained 12 RBG incandecent lights that I wanted to turn on and off in different patterns. I knew that theater people had faders and switches and things, but I wanted to control everything with a computer, and sync it up to music and visuals. I looked into those horrible X-11 things, but the latency was a ridiculous second or two range after sending a signal, and i needed at least 10ms accuracy. Enter what is, perhaps, the most dangerous thing I ever constructed and screwed to the ceiling of a remarkably flammably wooden building: the light grid and party capacitor.
I'd been doing a little bit of microcontroller work for a professor at Temple University, so I had enough chops to wire up a microcontroller over a serial adapter that woudl turn pins on and off via some simple byte codes. The brains of the system were just that, a 40pin PIC chip with a serial interface to a computer, a few transitor arrays that would let me switch more enough current with the PIC's pins to control electromechanical relays, and electromechanical relays that would let me control a terrifying 120volts a piece... 25 of them....
My father is a practical and skilled woodworker from the original This Old House school, and repurposed some varnished plywood he had lying around to build the box. It was about the size of a large suitcase with a handle screwed into the side. On the far end were two computer-power-supply-style electrical sockets to drive the arrangement of 13 (lucky!) electrical outlets that festooned the hinged top of the box, none quite square. Each of these outlets was split so that each individual socket could be separately controlled, and beside each of those I mounted (with a hot glue gun) a small electromechanical relay rated for 5A/400V. These would be in line between the AC current coming in from the wall and the outlets, with wires going from each to the microcontroller, where the turning on and off of its pins would trigger tiny 12v electromagnets to energize, closing mechanical switches in each relay that opened the 120v floodgates to whatever light happened to be on the other side. I also had three spare general purpose relays in place that were not hooked to 120V that I could use for fog-machine-related purposes.
Also of note, all this was in addition to a wall of TVs we had wired to a handful of VCRs, which used exclusively as RCA->channel3 adapters so we could run video over the cheapest, crappiest spool of coax cable money could buy. It was a thing, and it was complicated.
The lighting grid got finished on time, and worked more or less perfectly except that it ended up requireing a cooling fan and a bunch of heat sinks on all my transistor arrays (again, SUPER SAFE). After wiring those up, I let it sit on our dining room table for a while and run a chase sequence of the colored bulbs I would use for the party capacitor. The relays made a wonderful, gentle clicking sound when they turned on, reminiscent of the old flapping text displays they'd have at train stations until 10 years ago or so.
The video for the party was controlled by a Max/MSP patch, and the lighting cues were stored in a CSV, with each cue being the frame number of a video which was the backbone of the whole operation, and contained our music and visuals, and which had two sister videos that we kept fairly closely framesynced over the network with occasional polls back and forth. As the video played, it would pass its current frame number to a function that'd poll the CSV for a row that starts with that number, and if it found one or more, it would go through them and send ON or OFF signals to the lighting grid. Not the sexiest setup, but it worked very well, and we ended up plotting out over 900 lighting and video cues for this 4 hour party. We had moments where the party would get too high energy, and the capacitor would glow red, and fog would shoot out and warnings would flash on our 3 projectors and 11 television screens and then all the lights would go out. We had moments where fireworks videos would play on screen, and our strobe lights would flickr on and off at random, puffs of fog spitting out from either side. It was great, and I am eternally grateful that none of it caught fire.
Where is it now?
Jule and Steve, never ones to leave a man behind, went to the Fake House and retrieved the lighting grid they'd put there 5 years prior just before it was demolished. It now resides at Maurer Welding, with the promise that I would wire it up again in situ if Jule retrieved it. He called my bluff, and my promise remains outstanding.
- Photos and videos on Flickr
- Source code pending and potentially lost to the cruel sands of time