Hardware

Structural

The current version of the Pulsefield is a standalone aluminum structure formed of lengths of 1″ anodized square tubing connected using press-fit connectors from Etso and Brunner. It forms an hexagonal or octagonal (or larger) ring about 3 feet high with a single entry corridor.  All of the cameras and LED strips are then mounted on this structure to keep them stable relative to each other.

The time-lapse video below illustrates the assembly of the Pulsefield.

Computer

The main subsystems shown in the system architecture page can be run on any MacOS computer or set of computers, since the software modules communicate over a LAN in any case.  It is possible to run the entire setup on a single Mac Mini (2013 version running OS X Server) at full speed.

LEDs

Strips of RGB Addressable LEDS are mounted around the inside perimeter near the top of the aluminum structure.  Each strip contains 160 individually controllable LEDs for a total of 960.  The LED colors (8-bits for each of red, green, and blue) are set from an Arduino running a custom program (in the Git repository) allowing all LEDs to be updated approximately 20 times per second based on commands from the LED Server program running on a Mac.  Custom hardware was designed and built to distribute signal lines and power to the LEDs.   With a maximum drain of 60mA per LED, total current approaches  50A at 5 volts .  Attempting to distribute that much power on anything less than 10 gauge wire results in severe dimming of the maximum light output.  Instead, power is distributed at 48V to custom voltage converter/regulators mounted near each strip end.   At full output the display is extremely bright — over 7,000 lumens.

Cameras

On six corners of the aluminum structure, slightly below the LED strips, high-resolution video cameras are mounted.   These 10 megapixel cameras from Arecont Vision communicate and receive power over ethernet cables.  To cover the entire field of view, the lenses on these have been replaced with fisheye lenses.  The cameras are housed inside a weatherproof dome security case.

Video

Video generated by the Pulsefield software is displayed on a 20′ x 15′ stretch fabric screen suspended behind the installation.   An extreme short-throw projector (Mitsubishi WD390U-EST) with 1280×720 resolution is used to project the image.

iPad

The ubiquitous iPad is used for monitoring the operation and control of the Pulsefield, using the TouchOSC app which communicates with the Pulsefield server over OSC.

 

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