AdrianFreed's blog

I almost killed Bob Moog

The 1989 International Computer Music Conference was a standout event in my career that almost turned into a disaster. My name was on three papers, CNMAT was beginning to function well, I met two of my childhood heroes there, Bob Moog and Wendy Carlos, and I was demonstrating an ambitious product in the trade show, the Reson8 DSP multiprocessor designed and built by myself and Marie-Dominique Baudot.

Leaving IRCAM in 1984

"Date: September 21st 1984
Duties: Computer Services Manager
Reason for leaving: Looking for a more research-oriented position

Adrian Freed is an extremely competent - and recognized - UNIX expert. Being always innovative and well organized, he was a very efficient group leader.

Adrian Freed was always available when needed, including off-hour moments (late at night or at weekends) when difficult tasks arose"

Jean-Pierre Keller"

My best π day

My best π day was in 1975 when I invented a new way to estimate π using elementary geometry and algebra. This wasn’t a particularly important result for the mathematical world because there were already so many ways to estimate π but it was one of those moments I can see now as watershed that strongly shaped the rest of my life.

555 Timer resources

History

There are few inaccurate histories of the 555 timer invention on the web so a good source is from the designer himself, e.g., http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzi...

He also wrote several interesting books. The history and detailed design considerations are covered in a book he kindly made available as a PDF file before his death in 2012: http://www.designinganalogchips.com/_count/designinganalogchips.pdf

Circuits

This is a reasonable compendium of interesting circuits using the IC: http://www.555-timer-circuits.com

Circuit Layout Design Patterns for eTextiles Appliqués with Conductive Fabric

In the usual approach to PCB layout traces are laid out to connect signals and power to the pads of packaged parts and I/O connectors. This is a style that evolved for very high speed digital circuits. One usually also employs ground and/or power planes or a ground flood.

This style is not convenient for eTextile Appliqués which are most commonly single-sided and are based on cut traces rather than etched boards.

Sound Making Technologies Ordered by Increasing Complexity/Cost/Size

The entries in this table with an * were briefly reviewed in the 3 hour workshop the 2018 eTextile Spring camp. As the table shows, these are in the middle of the affordability/complexity/size axis and were selected for their potential in e-textile and wearable contexts. We had the good fortune to have Bela well represented in another workshop at the camp. Bela is transitioning to a new compact form factor which will make it easier to use with e-textiles.

FastTouch Open Source Arduino Library for Fast, Portable, Low Fidelity Capacitive Sensing

The fast touch algorithm reimplemented in the library available here was developed for my FingerPhone Instrument. The fast touch library senses touch on any digital I/O pin on many embedded controllers with the Arduino IDE. This includes Atmega 8-bit, SAMD21, and Teensy. This includes most pins on most micro-controllers. A few micro controllers have analog input pins that can't also do digital I/O . The library relies on the ability to enable a built-in pull-up resistor on the pin being sensed. Here is the algorithm:
  • set the pin to output a LOW value for 1uS or so.
  • A Self Organizing Classification System by BLW Chapman

    I learned about this work as a teenager and managed to trace my fuzzy recollection while researching connections between textiles and electronics. It was published in Cybernetica Volume 2.

    "I have recently completed building an electronic model of the 'growth net' principle and will now give a brief outline of its method of operation."

    "What I described earlier as a common boundary now takes of the form of a moist fibre of cotton yarn connecting each input to the control grid of a pentode"

    Caña Dulce and Caña Brava in San Francisco

    Caña Dulce and Caña Brava is my favorite performance group of the latest recrudescence of Son Jarocho tradition. They have been active now for ten years. These notes and the translated article below were prompted by my joyful discovery this week that all the members of the group are also extremely skilled and generous teachers.