Intro to PC

8/3/2019 Intro to PC

1/9

Physical Computingsay what??

Thursday, November 17, 2011


2/9

Computer Interactivity as We Know It

Input:

Keyboard

Mouse Voice

Output

Text Images (static & dynamic)

Audio



3/9

Physical Computing Interactivity: Input

Sensors that detect:

sound (volume; frequency; language)

light (luminosity; chroma)

movement / speed

proximity (infrared); global position (GPS)

heat

moisture

touch

force / pressure

digital information (computer)



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Physical Computing Interactivity: Output

sound

lights motors

digital devices



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Transduction

A fancy word referring to the convergence of one form

of energy into another. For us, it is converting the

intentions of the user into action.

A microphone changes sound waves into variable

electrical voltage. Speakers reverse the process.

Sensors convert forms of energy into digital data that

the micro-controller can then convert into instructions

to trigger specific actions (more energy) by an output

device.



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Processing

Turn a light on and off and the relationship between the switch and the light is

direct: if the switch is up, the light is on; if the switch is down, the light is off.

Insert a computer in the form of a micro-controller between the switch (input)

and the light (output) and you can add complexity to this simple formula. Perhaps

two clicks are required to turn it on. Or perhaps it only works if another light in the

adjoining room is on. This requires processing.

Giving the user choice requires coding with an if-then statement. If switch 2 is

also on, then turn on light 1.

The Arduino board uses a simple programming language with lots of built-incode. Another (more powerful) programming language used for physical computing

is the Processing language.



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Circuits & Micro-controllers

A circuit is a closed loop containing a source of electrical energy

(e..g, a battery) and a load (e.g., a light bulb).

A circuit board connects wires from the transducers and

channels the input to the micro-controller Schematics are diagrams showing the connections between the

electronic components

Think ofmicro-controllers as small computers embedded on a

chip, whose job it is to act as a gateway between the physical

world and the computing world Arduino is an open-source, single-board micro-controller. It has

minimal bult-in intelligence. You have to clearly tell it everything you

want it to do.



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Electricity & Electronics

Electricity, and specifically electric current, is the flow of

electrons, which can be converted into energy that can power

mechanical devices (but only since the late 19th century!). A switch interrupts the flow of electrons.

A.C. (alternating current) travels in two directions and is better for

longer distances.

D.C. (direct current) travels in one direction

Most electronic devices use D.C. at low voltage, which is whythese devices come with converters

Electronics is a subset ofelectricity, converting the flow of

electrons into information; it uses very little power.



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Physical Computing Possibilities

Any action you can detect with a sensor can be

converted into digital information that can then be used

to control an output device. For example, someones position in a room as

determined by a GPS could control the choice or

volume of an audio selection.

Physical computing is used in toys, mobile devices,art installations, and interactive performance.

The skys the limit!

Thursday November 17 2011

Documents

Intro to PC