"MAKING SENSE VI"
25-28 May 2005
I attended the Making Sense VI workshop led by Erich Berger at Atelier Nord,
Oslo.
This workshop was an introduction to physical computing and sensor building. I took the opportunity to test the sharp distance detecting sensor I had ordered for the organ. I intend to use 8 distance sensors on the 8 stop levers to make them into dynamic midi controllers. I am also planning to use 2 distance sensors on the knee levers (but am currently uncertain as to where they should be installed).
DISTANCE DETECT 30CM; Voltage rating, DC:7V; Width, external:44.5mm; Current, operating DC:50mA; Depth, external:18.9mm; Distance, detecting:30; Length / Height, external:13.5mm; Output type:Analogue; Temperature, operating.
While the sensor is actually designed to operate with distances between 4-30 cm, I intend to use the first 4cm distance range (see diagram below) and invert the data.
Having soldered power cables to the sensor, I tested it on an osciloscope.
The next stage was to try it out with the Interface-z midi interface. Using
midi monitor I got a midi range of 0-90 when objects moved within a 0-4cm
range of the sensor. I then took the sensor and the interface to my studio
to test it on the stop levers (which also have a movement range of 0-4cm)
of the organ to make them into dynamic midi controllers.
(click on image for higher resolution)
I placed a piece of white cardbaord, which acted as the reflective surface,
on the back of the stop levers, and the sensor on the back of the stop lever
board. This installation worked well, and, as the first implimentation of
a sensor in the organ itself, felt like a real acheivement!
However, I decided to rebuild the organ with the sensor installed and discovered 2 conflicts that I had overlooked:
01. When I reconnected the stop levers to the sound module I discovered that
there is a metal rod I had forgotten about that obstructs the movement of
the reflective surface.
Solution: Either work on an alternative solution for the placement of the
reflective surface on the back of the stop levers, or work out a way to install
the sensor and reflective surface on the inner part of the stops bar.
02. Not all the stop levers slide smoothly when the stops bar was reconnected
to the sound module. Some of them snap into on-off positions - another feature
of the instrument I had forgotten to take into account.
Solution: Install the dynamic distance detector senses anyway, even though
some of them may eventually end up as acting as on/off switches.
REFERENCE LINK
For more info on the Making Sense workshops got to the project section of Atelier Nord's website:
http://www.anart.no