The Testing Range is Complacent Chaos

'Physical Computing' is the term used to describe that general interface between artists and geeks. Half the people who enter his classes are non-technical, almost? to the point of not being able to turn on a computer. These notes include tech stuff and URL's...

(These are my notes, and observations from Tom's talk. This is a mish mash of Tom's talk, and my thoughts on his talk. It is not always clear who said what. I am also extrapolating in places Sorry.)

Tom is a professor at the interactive telecom... Program at NYU. Tom's Physical Computing home page

During the course of the semester they design and build computerized art projects.

These are projects that live at the edge between art and technology. Things that are often 'easy' to do from the technical standpoint, but require a spark and a vision to bring physical artifacts into existence. Physical artifacts that implement an idea in electronics.

The physical computing program is for folks who are:

interested in hardware hacking
want to get their hands dirty
have little or no background in electronics

A former student of Tom's, and a FOAF (yury gitman, the creater of the award winning Node Runner game, and number one on the google search 'Wireless Art') introduced me to Tom before the talk. Yury graduated from NYU.

I told him that whenever I tried to hack hardware I ended up with solder burns and a pile of destroyed parts. He smiled and said that meant that I was doing it right. If only I had realized that in 1985, I'd be a different person today. Well, at the least I would have more solder burns.

They have an 'interactive design track' (check spelling) where they operate from this quote:

Interactivity is a cyclic process in which two actors alternatively listen, think, and speak." chris crawford, understanding interactivity

This makes me think of my different yard art ideas in a different way. Many of my ideas involve a single iteration in that process. The art becomes more compelling, more engaging, with each loop that is added to the iteration through the listen/think/speak loop.

The user reads a screen, or reads the 'text' implicit in the installation, thinks on it, and then pushes a button. The computer then listens, thinks, and speaks...

Do we have interaction when you turn on a light switch? Absolutely. You listen to the text created by the existence of the light switch. You think about your decision to change the state of the light (assuming that you have bought into the basic premise that the switch actually does something understandable and linear), and then you act by altering the state of the switch.

The switch 'listens' for the change in state, processes that change, and then speaks by zipping them electrons on through the gap... And you can repeat this process ad infinitum.

But that conversation isn't going anywhere. The electronic Foosball table (see below) has the same conditions. It supports the desired actions of the users, but it does not engate the user in a conversation. The jello instrument does...

I don't always want to be in a conversation! I am happy to turn the lights on by pushing a button. I also read trashy fiction more often than Shakespeare.

I'm interested in conversation with a twist. The Hello Fountain idea...a person passes by my house, and is greeted with playful fountains spurting up in response to their presence. As they walk past, fountains spurt up in order, or out of order. All in reaction/interaction to the actions of the person passing by.

So what is a computer? Tom has the students draw a computer. Invariably people draw a keyboard, mouse and screen...

Then he showed his slide "How we see the computer" (as a pile of componenents, and "how the computer sees us," (as a hand with an eyeball...as a dwarf-handian (?).

The work of physical computing differs from robotics. Physical Computing compared to robotics:

low level of autonomy vs high level of autonomy.
focus on input vs focus on output
simple programming relies on user intelligence vs complex programming that relies on machine 'intellegence'

We are used to having easy to use scripting tools. Perl is an example. With perl you can do quick and dirty software hacks that are powerful and easy to create. This whole model breaks down when we enter into the physical world. We expect to be able to hack software easily. We have no such expection on the hardware side.

Tom's work is all about enabling people to make these sorts of 'what if' statements at the hardware level.

'What if we could make a foosball table that keeps score automatically?"

Physical computing is all about 'Transduction,' the conversion of one form of physical energy into another.

Look at one form of energy and convert it to another...pushing a button turns mechanical energy into electrical....etc through the range of real world applications

(After this are URL's and fragmentary notes)

Forest Mims ... patron saint of physical computing

And now on to some meat...

Common microcontrollers...they are just a computer. bx24 microcontroller mem, voltage serial io ports and cpu... basic stamp 2 www.parallaxinc.com great place to start. great educational tools available... but...slow, and expensive vs PIC but once you blink the LED it is all downhill from there...you can do anything once you blink the LED! $35-40 apiece, so too much for starving art students. So now they use: BX-24 www.basicx.com faster better basic more features but fewer code samples available and still expensive relative to the BS-2 The mainstay of his work... PIC www.microchip.com -steeper learning curve a few more components harder to use but the most expensive pic is $10, cheapest under a dollar... The easy software environments are not free... needs an external programmer... used to need uv eraser... irc comment is that open source compiler exists...maybe gcc... javelin www.parallaxinc.com programmed in java wicked expensive, 80 apiece There are others, but these three or four do everything he needs... Sensors human to device conscious vs unconscious actions c. primary focus to send computer something uc. has other primary purpose... ex. person left room, primary purpose is to get out of room because he is bored, but computer can detect it... c. physical action should be clear and obvious... ex. where is the eject button for the cd on the Mac G4 tower... ie: where are the switches. uc. physical affordance may not be obvious. ex. scary anti theft detectors in Barnes and Noble are way obvious... c. sensing is ofen in a very contained area uc. wide area... c ex. buttons, switches, etc card swiper uc ex door entry floor triggers faucet sensors - should be a bit better!j motion detectors Discete vs continuous sensing (digital vs analog) discrete: discrete number of states...often just two. continuous: analog...sense a continuous, bounded range of states. resolution is theoretically infinite, but is constrained by A-D conversion Look at the application...how much resolution does it need? then double it. light - photocells heat - thermistors (chair sensor based on butt heat) The real world is messy! don't discount that...incorporate it into your project. Touch...capacitive field sensor Quantum QT113H - cool $3 chip. A mesh, like screen cloth-could have been wired to the easter egg foil Force sensitive resistors www.interlinkelec.com feliforce.com flex sensor www.jameco.com www.digikey.com Conductive rubber - press stuff www.allcorp.com other surplus retailers... Infrared Ranger Sharp GP2D12 - radio shack ir motion detector 49-426 is the same thing and then hack on the led... Did something cross my path? polaroid sonar ranger, ultrasonic ranger www.acroname.com lots of sensors here the polaroid makes noise object tracking video cmucam nice board...packaged camera w. microcontroller and serial port. can get image or x/y of brightest object on screen. costs about $100 track them colors www.smoothwae.com cyclops and jitter www.cycling74.com for Cycling 74's Max/MSP big eye www.stteim.nl Acoustic sensing... simple... sound level via piezo is easy use multiple piexos to one microcontroller for rough triangulation is possible. Complex... Frequency analysis via fast fourier transforms not easy on microcontroller, best done on desktop pc. "Go get a low end PC, throw it into the bottom of your project..." There is no operating system...infinite loops are okay. Everytime you do something, it is all you are doing...no event loop. so if you have a 'pause' you are not receiving your input... Device to device.. mostly serial we are just connecting blocks of things to do something, we don't care how those things do it. Just pulsing a wire on and off... Once you solve the problem of getting the wires connected it is software... Why not attach these to the net? ethernet is just another form of serial, so all you need is a microcontroller taht can deciper ethernet packets...an ethernet controller... www.embeddedtether.net embeddedethernet.com www.edtp.com/packetwhacker.htm (slide of a packet sniffer connecgted to a piano, every packet plays a note) Serial to ethernet modules higher level siteplayer.com $30 web server web interface udp send and recieve serial to talk to microcontroller 10 minutes and you are up! they made 30 banquest table centerpieces! cobox micro lantronix.com no web interface open a port and data is going... 2 serial ports really nice for unix programmers telnet into it, open a port. i he has a siteplayer attached to a fan. If a student hits his page looking for notes, he gets a little breeze. Wireless! radio -omni -large distances -good for many to many -higher power infrared -directional -shorter distances -good for one to one -lower power abacom.com links? RF pulse an ir led then read a photo diode... once you've lit the led, it is all downhill, even if it is an infrared led samples of student work... Big Brother foosball goals connected and card reader to track who is playing. There is only one concsious action-swiping their card... Jellophone by michael sharon... and because he is a bit of a freak, he likes to play with jello... squeeze jello and you hear notes...great fun Flight Simulator for birds...wired stuff to themselves and you flap your wings, lean, etc! They didn't know enough code to leave the trees on the ground, so the trees fly with you... :-) all of this is stuff you can get your hands on now! itp.nyu.edu/tigoe/pcomp bioinformatics, like hand readings, very off the shelf but 3-400 bucks each. siemens makes a mouse that has a fingerprint reader for $100 802.11b dev kit? iosoft.co.uk/wlan.php (broken url) someone talked about ambiant orb... and oem gps's are out there... the guy took a 'taplight' as a good container and put in led's and wierd epoxy hooked to a pic and an RF tx/rx to a serial... A Cool Taplight project Cormac also talked about the slimp3 ... an mp3 player with a rj45... with a two line display... how about a search engine voyers to a little display as a break the ice tool...you are at a party, not sure what to talk about... passive devices rock.

Oct 1, 2007 - Hire me to do something...