Going Servo

So I have this desire to redo "Breath" using a servomotor to accurately actuate breath strength, rather than just on/off. Here are some options:

1) Pololu has a 3A Motor Controller with feedback($49.95). It works with a tach on a motor, and you can interrogate it over USB to control/configure it and get all kinds of neat info. It also works with TTL, PWM, and analog input for control.

2) Geckodrive G320X 20A ($114) motor controller that works with a quadrature encoder. It only accepts pulse control. This is probably great if I needed bi-directional strict control of a big expensive motor with a quadrature encoder, but is probably overkill for a fan.

3) Encodergeek's Model 100 3A ($99) motor controller. It isn't clear to me if it works with tach or quadrature encoders (though he sells quadrature encoders, so you'd think it would work with them) and does pulse and analog control. He also sells his own 3A motors with encoders for $40, as well as compatible gearboxes, encoder wheels, encoders.

Also I'd need a motor. A case fan needs to spin up to 2K-3K RPM or so. I saw some motors with tach encoders over at All Electronics in Van Nuys, maybe I'll check there and see what they have.

Updates

Here are some quick updates:

My Breath OSC Interface App is now on iTunes, hurrah!

I am picking up from three years ago on DogCeleration. Especially now that my beagles are in LA and just had their first movie released, I thought they should join the art world as world. They key to interfacing with the Bluetooth BlueRadios on OS X is Zterm, just remember to hit shift when you run it to choose the right connection.

Alberto Gaitán recently mentioned the existance of Pachube, "realtime sensor, energy and environment data", which includes wind sensor data. Which would be a great source for "wind over IP" to a servomotor driven fan.

I also recently picked up a Mini2440, which is an awesome Linux-capable ARM-based SBC with Ethernet, serial ports, A/D converters, a cheap camera, and much more! I am still exploring it, but it seems pretty cool.

Breath OSC Interface iPhone App Support

This page is for support of the Breath OSC Interface iPhone App. Please feel free to ask any questions or provide bug reports below.

Ordered SheevaPlug

So I went ahead and put in an order for a SheevaPlug. They say it will take "2-3 weeks" from order date. I ignored the GuruPlugs because of the reported heat problems. I may use the SheevaPlug as a "more reliable/powerful" network interface for physical computing systems like Arduino that can hang off of its USB. I may also use it as an el-cheapo "meet-in-the-middle" server for PHY2PHY projects.

No sooner had I ordered the SheevaPlug did I see a neat mini-systemboard ALIX3d2. LAN / 2 miniPCI / LX800 / 256 MB / USB / 500 MHz AMD Geode LX800, $99. Needs an external DC power supply. But, hmmm.

Then I saw the Mini2440. Also in the $100 department, it has a 405 MHz Samsung S3C2440A ARM920T chip, a 3.5″ touch screen display, 2MB NOR flash, 64MB SRAM, and 128MB NAND flash, Ethernet, USB, COM, audio out. It comes preinstalled with Linux 2.6.3 and a Qtopia graphics. There seems to be a version without the touch screen a bit cheaper here. And it appears to have a cheap camera available as well. And, oh yeah, it has 8‐channel 10 bit A/D converter with sample and hold, and a bunch of digital GPIOs (more info here). And here is a video of the GPIO at work. This sounds like an awesome system for PHY2PHY projects, it could be its own webcam and webcam display as well.

Tesseract OCR

If you need a free OCR program, try Tesseract. It is awesome!!! Skip GOCR.

No problems building it on OS X. One thing you may need to know is to use ImageMagick "convert" command with "-depth 8" to build TIFF files that Tesseract can read.

Breath-over-IP redux

So honestly, my breath-over-IP project is not at cool as I want it to be. It actually an on/off system rather than a more "analog" transmission of breath speed.

The problem is that the anemometer impeller and the output fan both have too much inertia. The anemometer impeller is incredibly sensitive, but once it starts spinning it can take several seconds to stop, even without any breath. The fan is the same way, once you turn it off, it takes several seconds to spin down.

So I am contemplating redoing Breath-over-IP using a servo motor and servo controller. This should allow me to speed up and slow down the fan motor very quickly. On the breath sensor side, I could use a pressure sensor chip.

Finally, I'd like to solve my networking challenges using a plug based Linux PC with a USB-attached Arduino. That way I can do very complex networking in Python on the plug computer, and let the Arduino handle analog/digital I/O, which it does well.

So that's my plan...

Physical Computing Talk TONIGHT [Thousand Oaks]

“Physical Computing – Interaction Design and Systems Engineering”

Wednesday, 10 March 2010, 6:30-8:30pm

Richter Auditorium, Cal Lutheran University, Thousand Oaks

Meetings are free and open to the public. Parking is free.

Carlyn Maw, a co-founder of CrashSpace, a Los Angeles Hackerspace, formerly an instructor and graduate of NYU ITP, presents an introduction to Physical Computing.

Physical Computing is a hands-on multidisciplinary approach to interaction design and systems engineering. It is neither electrical engineering light nor advanced hobby electronics, but rather a holistic approach to invention and problem solving. Practitioners are frequently experts in their fields who want to harness the power of electronics within their own discipline. Examples include:

· A musician composing a symphonies based on data collected from sensors on the body.

· An occupational therapist working to develop a pressure vest for children with sensory modulation disorders.

· A scientist tracking monkeys.

· A fashion designer creating a dress that unfurls like a flower.

Physical Computing methodologies quickly grab the imagination of beginners by treating electronics and programing as tools which extend what the new-comer already knows rather than as complete separate realms of expertise. With an emphasis on learning by doing and rapid prototyping, Physical Computing provides a quick pay off for those just starting out and for experts making “sketches.”

Additionally, Physical Computing has become a way of life for the communities forming around it. People around the world are working to increase the accessibility of the making things way of life. Carlyn will provide an overview of the conceptual approaches, tools, people and communities that are contributing to Physical Computing today.