learning the ropes » Happy Feet

Michael — Tue, 12 Dec 2006 01:32:02 +0000

- Modified MAX patch to playback samples instead of routing notes to a MIDI synthesizer
(full comments are found in 12/1 notes)

User Testing

Michael — Sun, 10 Dec 2006 00:05:02 +0000

Michael — Wed, 29 Nov 2006 02:51:03 +0000

- Continued construction using the perfboard/shrink tubing sensor package and finished two shoe prototypes
- User Test – Patricia (using foamboard prototype + Korg synth module)
- Felt that more sensitivity was needed. She found it difficult to trigger the samples without stomping really hard
- Didn’t like bass drum on the heel; felt it would be more natural on the front
- Cannot tell where the sensor is — perception is that it is close to the center of the shoe
- Feels the system is more responsive with the 10k resistor than with the 2k
- Could play either sitting or standing
- Would like to play along with some other music

Michael — Sun, 26 Nov 2006 03:03:41 +0000

- Problem: Sensitivity Training. It is difficult to get the sensors to trigger samples consistently. We’re concerned after studying the FSR datasheet and application notes that we might be saturating the sensors and going outside of their useful operating range. We try replacing the 10k resistors in the sensors’ voltage dividers with 2k resistors. We are also trying to eliminate the opposite problem: standing still on the prototype triggers samples. Is the circuitry too sensitive?

- Problem: The MAX patch plays two notes simultaneously. We work to debug this issue by breaking the MAX patch into sections… first by printing the received note data, then watching this data as it propagates through successive objects in the patch.

Michael — Tue, 21 Nov 2006 23:48:40 +0000

- Breakthrough: Tried sandwiching sensors between layers of foamboard in the hopes of avoiding sensor wear and exposed wiring. Much of the discussion continues to focus around protecting the sensors.

Michael — Fri, 17 Nov 2006 02:11:00 +0000

- I ordered connector samples from Samtec: female headers so we could prototype the FSR strain relief packages and 6-position modular jack connectors in the event we want to build printed circuit boards for this project.

Moving to MAX/MSP

Michael — Mon, 13 Nov 2006 02:44:02 +0000

- Finished rewriting Arduino code to send sensor data to MAX/MSP as NoteOn/NoteOff messages. This patch takes the NoteOn message(s) sent from the shoes and can remap them to different note numbers so it is not necessary to modify the Arduino code every time we want to change the sounds.

- We’ve been destroying FSRs. The tiny staples which make contact with the conductive layer of the FSR fall off if too much heat or pressure is applied.

- Discussed strain relief for FSRs. Lisa is going to call Interlink to see if we can get replacements for free. (see 11/12 notes for picture of initial strain relief Prototype)

Michael — Sat, 11 Nov 2006 00:00:00 +0000

- Crimped modular connectors (RJ-11?) onto the ends of phone cable. We are planning to use these connectors and jacks to improve the reliability of our system. These will replace the stripped wires plugged directly into the breadboard.

Michael — Wed, 18 Oct 2006 02:56:58 +0000

(from Lisa)

We continue to work on the housing for the sensor. We explore other
options to the lucite house, as the machining of it really time
consuming. We go back to the lucite housing, and retest the sensor to
make sure it still works. Michael does some stomping. It still works.

The question is as to whether this housing will last long-term as
built. The area with the solder seems to be the new vulnerable spot.
(Before the “ vulnerable spot” was the connector.) Will our strain
relief stand the test of time?? Stay tuned patient viewers..

We decide to create 2 versions, one is as described above, the other
is heat shrinked.
We are almost ready for user testing! Woo-hoo.. We still need to
attach them to the shoes, and will be attaching one to the front left
and the other to the front right, and seeing which is the victor, in
the test of durability.

Michael — Tue, 17 Oct 2006 02:53:31 +0000

(notes from Lisa)
Making a really robust flex sensor and a package to contain it.
The task at hand is how to house the sensors so that the “tail” will
be protected, and still function.
We start using a perf board, then put heat shrink tubing on the
sensors in order to that the contacts were secured.

We are looking to cut a hole out of the lucite blocks.
The idea is to make a channel through it to protect the top of the
sensor from being stamped and stepped and stomped on.
So we attach the female header to the perf. board, and solder it on.

I don’t like that I can’t make a clean square cut with the dremmel
tool on the lucite-housing.