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[on:]

hi! i'm completely new to arduino and would like to know if it is possible to use it for my art installation that will be on a 20x20 billboard. essentially i would like to create a piece that looks like it's a "breathing" wall that expands and contracts in a gentle rhythm, using inflatables. The rising and falling of the piece mimics a living organism and will be controlled by the air quality in Los Angeles. So if it's particularly bad that day, the breathing will quicken, as if it were out of breath. I'm thinking that I will need an air compressor that can push air out and in and then hook up arduino to an air quality sensor or maybe a RSS feed online of air quality. However, that is really all I know and I would REALLY REALLY appreciate any help on this matter or how this could work. Thanks SO much in advance!!!

[Reply #1 on:]

Hi Karen,
OK, 20x20 in USA = Feet, right?  Just to understand scale.

How many segments might this installation have?

What might the horizontal displacement of the wall sections be?

Try to estimate the cubic feet of air that would be moved in a "breath in and out"..

Guesses:
- You need both positive and negative pressure to quickly move the sections in and out
- There is a 'lot' (several cubic feet) of air to be moved each 'breath'.
- The PRESSURE can be quite small (there is so much area)
- The VOLUME is fairly large
- An air mover much like a "Shop Vac" that has both input (suction) and output (pressure) ports may be workable. But noisy.
- The air pipes and valves needed to move this volume of air quickly need to be large. Maybe like the 2 1/4" Shopvac size.
- There are valves made for switching air pipes for dust collection in woodworking workshops
- "Servos" may work for controlling the valves.

An opinion: You can do the control part with Arduino.  The infrastructure and valves are the hard part.

Another: Embrace Stepwise Refinement and Prototyping. AKA "Get something small to work first!!"

Go for it...

[Reply #2 on:]

I'd be inclined to go for a mechanical drive mechanism rather than a blower, since it will be quieter and consume less power and be easier to control. If you have already designed the display portion and committed to it being pneumatic, I'd use some bellows to operate it and a mechanism to operate the bellows. It seems to me that what you're asking for so far would be achieved with a variable speed motor and a crank to operate the bellows. (If you aren't committed to pneumatics, I'd connect the crank directly to the moving parts.)

[Reply #3 on:]

Another consideration is how do you plan to get the air quality data the movement is based upon.  If the data is from local sensors (i.e. sensors in or around the "breathing" wall display) you can wire them directly to the control unit.  However, if the data is coming from sensors blocks away or aggregated from all over the city you'll probably need some sort of Internet connection (wired or wireless) or RF transceivers.  In either case you could use an Arduino-based system, but there can be a significant difference between the two in some of the parts you need, how you put them together, and the programming.