MEA10731 // Mini Project // conductor stand

For our mini project we chose to design and prototype a semester project related artefact. Our semester project is called Orkestrariet and based on a project call from DR for a new music experience center called Musikarium.

The Orkestrariet is an interactive music learning installation using finger tracking. Until now, the system needed to be activated/deactivated by pressing the enter key. For a public installation, this is definitely not an ideal input method.

So what device could improve the interaction? Verplank’s interaction design framework was used to design the concept this mini project is based on:

It was thus decided to build a wooden conductor stand for the user. So to trigger the application, the user needs to step onto the stand. The application status is indicated by a curtain in the interface. If the application is active, the curtain is open and displays the orchestra. If the application is deactivated, the curtain is closed. Stepping off the stand automatically ends the session thus closing the curtain, saving the user data and deactivating the system.

To register a user, a force sensitive resistor (FSR) was built into the stand. The following sketch illustrates the stand.

The actual stand consists of the frame (image 1), a bottom plate mounted onto the frame with the FSR attached to it (image 2) and a plate losely placed on top of the bottom plate (image 3).

image 1

image 2

image 3

For installation purposes, 2 footprints on the top plate indicate where the user needs to stand. Furthermore, an instruction plate was designed. It explains how to use the system.

The FSR is connected to a CUI32 board. Using a small program written for StickOS, the CUI32 sends the analogue input signal of the pin the FSR is connected to (an3) to a patch in MaxMSP.

StickOS program:

10 dim a as pin an0 for analog input
20 dim b as pin an1 for analog input
30 dim c as pin an2 for analog input
40 dim d as pin an3 for analog input
50 dim e as pin an4 for analog input
60 rem — pin an5 usurped by USB —
70 dim g as pin an6 for analog input
80 dim h as pin an7 for analog input
90 dim i as pin an8 for analog input
100 dim j as pin an9 for analog input
110 dim k as pin an10 for analog input
120 dim l as pin an11 for analog input
130 dim m as pin an12 for analog input
140 dim n as pin an13 for analog input
150 dim o as pin an14 for analog input
160 dim p as pin an15 for analog input
170 configure timer 0 for 10 ms
180 on timer 0 do print “A”,a,b,c,d,e,”0″,g,h,i,j,k,l,m,n,o,p
190 while 1 do
200 endwhile

Excerpt of the patch in MaxMSP:

The analogue signal is fed to a threshold which then controls the binary message from MaxMSP to Processing (sending 1 when the FSR detects pressure (any value >0) and 0 when there is no pressure). We used MaxLink External library in order to communicate from MaxMSP to Processing which is where the main Orkestrariet application is run. The received value (1 or 0) controls the activation/deactivation of the system.

The following video shows the working prototype of the conductor stand.