- contract works
Ausstellung Zeitmaschine campusCOUNTdown / / LED Counter Design – 14.6.2012
The project “Hörverbindung zur Quelle” is an art project by Katarina Hinterlechner. It consists of a modified phone booth which allows users to listen to the gurgling noise of the different fountains that make up Vienna’s water supply.
This project was part of the centenary celebration for Vienna’s water main supply. More Details can be found on this website (in German).
Planning, organization and mechanical construction by Katarina Hinterlechner and Christian Deschka,
Hardware and software engineering by Simon Laburda
Here are some pictures of the construction process (I’ll upload more pics of the finished project soon):
We were contracted by Areus Engineering to develop a control system for a passive LED matrix of up to 768 white LEDs (48×16 pixels). The LED-matrix was attached to a scale model of the prototype for a Maybach car. The idea of Michal Plata was to make the car sort of invisible by recording video from one side with a webcam and projecting it to the other side. (If you’ve seen the James Bond movie “Die Another Day”, you’ll know what I mean ;) ). “sort of invisible” because of course with blocky 48×16 pixels and no colors you could never do an accurate representation….
The LED control-system should be able to receive pixeldata from an attached PC and do 16 shades of gray. With this configuration our system managed to display 15fps with a refresh rate of up to 100Hz. The pixeldata came from a webcam attached to a Linux Netbook. On this computer the image was scaled an dedistorted using OpenCV and transferred to the LED-screen using ledbridge.
The controller had to drive the 15mA rated LEDs at 240mA to achieve the full brightness while scanning through the 16 rows, yet never stop scanning the matrix because that would burn out the LEDs instantly! Achieving the high frame- and refresh-rate with the ATMega32 was a difficult task, I had to think of an optimized framebuffer layout to decode the incoming pixeldata to in order to achieve the high refresh rate. Also I had to use assembler because with C the required performance just can’t be reached.
The Lighthead Projekt consists of a number of semitransparent helmets. A single helmet contains a 433 MHz Receiver, a microcontroller and very bright leds.
We controlled it by using processing running on a small linux machine directly hooked into the audiomixer.
Developed for Katarina Hinterlechner and Christian Deschka
The cube MHE-Cube was my first LED art project. It was a gift from a number of employees at Statistics Austria to new founded company MHE & Partner. The cube form was chosen because that company was working with “OLAP Cubes” which is a form of representing data in a three-dimensional table (sort of…).