learning the ropes

Work continues on the second “PeopleScrubber.” I started off trying to make another more robust prototype so I could start experimenting with the content of the performance, but I got hung up on making the prototype. I thought I would try a combination of wire and cardboard for this prototype so I wouldn’t have to do so much cutting. It turns out that making the prototype with wire was more labor intensive because each piece had to be made by hand. The last prototype I made seemed easier; I drew templates for the in Visio, printed them out, glued them onto cardboard, and then cut them out.

Jamie had mentioned using a mouse to do the tracking, so I tracked down a free PS/2 mouse on Craig’s List and found Arduino code that implemented the PS/2 mouse serial protocol. Fed up with the last prototype attempt, I made a breakout connector for the mouse using a salvaged dual PS/2 mouse/keyboard jack from a computer motherboard on the junk shelf in the Physical Computing lab.

The test program ran perfectly and reported x and y movement (as deltas) as well as mouse button states. Very slick! There was only one problem: I would need to send serial information from Arduino into MAX/MSP. The test program I was working with printed out
1000010
x=123
y=-3

There were no delimiters other than carriage returns. I tried to figure out some way to interpret the strings using MAX/MSP, but I became extremely frustrated. Parsing strings in MAX/MSP is not pleasant. It’s alot like parsing strings in SIMPL. Again… unpleasant. The reason I wanted to parse the strings is so I could make sure the MAX/MSP patch would interpret the values in the correct order. With the “x=” and “y=” tags in front of data, I could be sure the x and y values weren’t being mixed up.

Once I started experimenting with the “=” character as a delimiter, I realized there was another problem with this scheme: the numbers could be variable lengths. This would be easy to handle using a procedural programming language, but I haven’t found anything like a “mid” or “left” function in MAX/MSP. I set the project aside for a bit to see what other ideas might present themselves.

I was really at a loss for what to present as a prepared interface. Rummaging around on the junk shelf at ITP I found the remains of a Sony compact bookshelf audio system with a 5-disc CD changer. I thought I could prepare something using the existing interface and the mechanism inside the device.

Originally, I thought I was going to make some sort of audio player, but the volume control had been salvaged from the unit.

Then, I thought I could use the trays in the CD player to pull strings and control an improvised kinetic sculpture. There was only one tray.

The following is what I came up with: using the interface and mechanism of the CD player as a filing cabinet.

I started off by making some paper “CDs” to put in the unit, but realized that it would hold the little business cards I carry around as my on-the-go notepad. The sound of the mechanism and the motion it made to deliver the cards from its electromechanical bowels was precious in an unexpected way.

I constructed some ear rigs for Urinetown based on some notes I found at Bright and Loud. The first set of rigs had long boom arms on them which the audience could easily see, so when I had to make a second version for Officer Lockstock in Urinetown, I modified the design to be much more discrete.

You’ll need the following supplies to make the rigs:

* 18 gauge wire (available from hardware stores — used to hang suspended ceiling tracks and repair fences)
* assorted diameters of heat shrinkable tubing
* solder
* flesh-colored Prismacolor or Zig paint markers
* pliers and wire cutters
* heat gun
* soldering iron

I took photos of each step. You can see annotations if you click on the images.