This project was commisioned to GK Tech by Kansai Electric Company located in Osaka, which has a large headquarters building in the city. The goal was to create an interactive installation for an outdoor platform which overlooks the high-rise. On top of Kansai building, there is an array of blue and white neon tubes arranged into an undulating shape and displaying an aurora-like animation governed by the motion of the wind. The sensing of wind velocity and corresponding animation has been previously developed by GK. (A similar animated display, also by GK Tech, can be seen on top of Mirai-kan science museum in Odaiba)

The installation we developed for Kansai was a bean-shaped object attached to a railing on the observation platform at shoulder-height, allowing visitors to interact with it by touching its surface. The object takes its shape from the neon light arrangement of Kansai building and it is illuminated from the inside by strips of blue and white LEDs that mirror the large display animation. A grid of infrared sensors is intersperced between the LED lights on the inside of the bean, allowing its entire surface to become responsive to near-proximity. By touching or sweeping hands across the plastic surface, visitors can affect the animation of lights on the installation as well as the large neon display visible at a distance.

I feel very fortunate to have had a chance to work on this project at GK as it represents a culmination and something of a personal "next-step" in terms of technical possibilities explored over the last few years. As this installation required an integration of a rather large number of LEDs and sensors updated in real-time, we decided to implement a hardware pipeline using programmable logic (FPGA) architecture.

The final design utilized two small boards by HumanData based on Spartan-3 FPGA family by Xilinx, together providing 128 channels of (normalized, 256-level) PWM output for LEDs and 32 channels of sensor input (for a total 256 sensors), processed in parallel. A working prototype of the installation was developed in the spring 2005, after many a 120-yen milk coffee and some number of sleepless nights debugging VHDL code with an oscilloscope ;)

GK Tech

Kansai Electric Power Co.

New KEPCO Building
I didn't get to visit the building intended for the installation, but this may be it.. the site seems to catalog every highrise in Japan!

Xilinx Spartan-3 FPGAs
A family of low-cost FPGAs compatible with the company's free ISE WebPack HDL synthesis environment.

Side view of the glowing bean, the plastic cover also acts as led diffusing material.
Another view of the object showing some light streaks animating across the surface.
Exposed view of the led structure and wiring during development.
Closeup of one of two programmable logic boards, each a parallel pipeline for over 100 digital I/O!
One stackable set of 32 electronics PCBs.. an led driver board on top and 8-channel infrared sensor board on the bottom.
Closeup of the two boards snapped together.. the LEDs and InfraRed sensors are visible poking through the holes in the top PCB.
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