[Lab] Controlling Light with a Ventilator
The Big Plan - Chris B
tbp at ghostwise.com
Sun Mar 24 16:05:45 EDT 2013
Hi Modlabbers (and especially Kirk, Roman and Henri in this message)!
Thanks so much Kirk for going ahead and programming a RaspPi dimming
function for the projector.
I think the projector is probably the best way to control the lighting
versus investing in LED lighting. How would I
connect the RaspPi to the projector?
From all the suggestions I've received on the list, I'd like to use
these two items to control the lighting via the ventilator:
A pressure sensor <http://www.digikey.com/product-detail/en/MPVZ5010GW7U/MPVZ5010GW7U-ND/1168379
I've never used a RaspPI so I don't know would I need for it. What
kind of cables, enclosure, PSU does it need?
If the order requirements could be spelt out to me I'd appreciate it.
I would then go ahead and order the equipment
needed to do this.
Last night a friend suggested a possible problem: If I backlight the
painting, the squares on the front may end
up simply looking dark. Would it be smarter to project onto the front
of the painting? I was hoping the light source
wouldn't be so apparent but if the visual doesn't work with
backlighting, I may have to. It is a pretty thin layer
of acrylic paint so the light may glow through it.
I'm also trying to figure out how to suspend the canvas. It's not
stretched on a frame. I'd like to keep it loose like a
sail with it bulging a little forward towards the viewers. My friend
suggested using a fan on low to keep it bulging
forward. I wonder if the same effect could be done through tension.
As a BIG aside, If I had an iPhone, iPad and possibly a computer all
working together to create music, what would
I need to make the painting into a giant visualizer for the music? :D
I suppose video of a visualizer of some sort
would have to be projected onto the canvas.
Thanks again for all your interest! I hope I can put together version
1.0 of the painting installation in May / June.
On 24-Mar-13, at 12:33 AM, Kirk Sutherland wrote:
> Hi Chris,
> I had a chance to try out the visual aspect of what you are
> describing on a Raspberry Pi and it was pleasantly easy! The code
> was written in Python on a stock install of the operating system
> 'Rasbian', I simply turned on the Pi, wrote the code and ran it -
> didn't have to install anything else!
> The code displays 5 'breaths', each cycle lasts 2 seconds going from
> black to full white. If you had the Pi connected to a projector as
> your 'light' I believe this could work nicely. There are some
> artifacts as the colour changes because I am simply refreshing the
> screen really fast, but if you have you canvas to act as a diffuser
> I don't think you would see them.
> Have you picked your sensor yet?
> On Mar 22, 2013 9:03 AM, "Kirk Sutherland"
> <kirk.sutherland at gmail.com> wrote:
> I second the raspberry pi as a projector controller! Its cheap,
> projectors are bright (and can be borrowed!), and I don't think the
> code would be that hard. You will have to use some external
> controller with the Pi if the sensor is analog as the pi has only
> digital io. I could try out some simple code tonight to see if the
> video part is possible without getting into opengl code :)
> On Mar 21, 2013 9:21 PM, "Henri Kuschkowitz" <henri.kuschkowitz at gmail.com
> > wrote:
> Hey Chris,
> I know you already received tons of ideas, but i was thinking about
> a mini fan put somewhere between parts of the tube (maybe after the
> bacteria filter) and you then just measure the speed of it to
> determine the power for your lights?
> For the question regarding lights, there are hundreds of
> controllable led strips out there that could suit your needs. or
> maybe EL solutions (though it would cost you more i think) like
> this: https://www.sparkfun.com/products/10800
> Also, you can dim a projector simply by projecting grey scale
> images… which means a raspberry pi connected to the sensor could be
> a neat solution.
> Just my 2 cents.
> Cheers and good luck,
> On 2013-03-21, at 5:46 PM, The Big Plan - Chris B wrote:
>> Hi Modlabbers,
>> Thanks for all the interest in my art installation!
>> So far it looks like the pressure sensor idea is the one I'm
>> leaning towards. Having a microphone detect the ventilator breaths
>> sounds more finicky to me.
>> Still trying to figure out how to back light the canvas. Would a
>> projector work instead of using LED lighting? Can a projector
>> be connected to the pressure sensor set up to do the variable
>> Club SAW has 3 projectors available:
>> Panasonic PTAX200U HD Video Projector
>> 16mm Projector
>> 35mm Projector
>> As for a timeline / schedule. If I could do this in May / June that
>> would be great but it may be more realistic to wait until September.
>> Here's a photo of the painting below. It's about 7 by 11 feet:
>> <2012-11-12 14.51.55.jpg>
>> On 15-Mar-13, at 8:41 AM, Michael Sepa wrote:
>>> The clarification of the project really helps out. I looked up
>>> the manual for the Puritan Bennet LP10 (http://www.meql.com/Manuals/Puritan-Bennett-LP6-Plus-and-10-Ops-Manual.pdf
>>> ) in the hope that there would be a simple electronic monitor
>>> connector on the back that you could hook into, but no such luck.
>>> There are pressure alarms that can be set and a remote alarm
>>> connection on the back of the machine, but you'll get audible
>>> alarms off the machine at the same time. Not what you intend.
>>> One approach would be to do the following:
>>> 1. Lights start off, no ventilator pressure
>>> 2. Ventilator turns on, a microphone beside the patient air tube
>>> senses flow
>>> 3. Arduino detects change from microphone
>>> 4. Arudino uses pulse width modulation to brighten an LED array
>>> from off to full on in 1.5s, and holds
>>> 5. Ventilator turns off
>>> 6. Microphone detects stop of flow from patient air tube
>>> 7. Arduino uses pulse width modulation to dim an LED array from
>>> current level to off in 1.5s and holds
>>>  pulse width modulation is just a fancy way to say turn on/off
>>> the LED array fast enough to control brightness. This is built
>>> into the Arduino system, so it's very easy.
>>> Connecting to and dimming an LED array with an Arduino is well
>>> understood. No issues there.
>>> The microphone will require an amp chip to get it producing a
>>> signal the Arduino can easily read. If we can find a pre-made
>>> microphone and amp, then it will be all so much easier.
>>> The programming of the system would be straight forward.
>>> Certainly less than a day of effort.
>>> The system would work well if the room was reasonably quiet. If
>>> there was other noise it might trigger the microphone causing
>>> premature light adjustment. A better approach would be to use a
>>> pressure sensor. I checked ebay and see several pressure sensors
>>> available, all use I2C interfaces. That would take a bit more
>>> programming effort, but certainly less than a day or two.
>>> If you go with a pressure sensor, we'd need to makes sure the
>>> sensor has the right range to sense the ventilator pressure. That
>>> I couldn't get from the quick ebay search because they don't
>>> usually publish specs with sale items. I'm confident we could
>>> find an appropriate one on ebay, spark fun, or somewhere else.
>>> As for your budget, I'd think you should have no issues buying all
>>> the tech plus paying someone a small honorarium for helping you
>>> program it all.
>>> My big question would be what's your schedule?
>>> -Michael Sepa
>>> Date: Thu, 14 Mar 2013 17:49:08 -0400
>>> From: The Big Plan - Chris B <tbp at ghostwise.com>
>>> To: lab at artengine.ca
>>> Subject: Re: [Lab] Controlling Light with Sound
>>> Message-ID: <F3148EB9-8831-464E-92AA-2144AB15E72B at ghostwise.com>
>>> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
>>> Hi everyone,
>>> Thanks for the awesome replies so far. I think I should clarify my
>>> My plan is to suspend a loose canvas that is approximately 7 by 11
>>> feet on an angle from the ceiling.
>>> I would like to put lighting behind it (I don't know what lighting
>>> use or whether it
>>> should be a set of lights). The rest of the room will be dark.
>>> A ventilator (Puritan Bennett LP10) will be on the floor. Every
>>> of the ventilator
>>> should cause the lights to turn on in a gradual way and then dim
>>> as the breath
>>> ends. Each breath should take about 1.2-1.5 seconds.
>>> I like the idea of an Arduino or Raspberry Pi controlling the
>>> It sounds like I will also need a mic by the ventilator.
>>> Finally, I have zero programming experience or overall technical
>>> experience to do this. I'm the artist
>>> with a vision. I would appreciate assistance from anyone
>>> interested in
>>> this project.
>>> It would be great if it could be done on a $250-500 budget.
>>> Thanks in advance,
>>> On 14-Mar-13, at 4:11 PM, The Big Plan - Chris B wrote:
>>>> Looking for some advice for an art installation. I'd like to have a
>>>> light or set of lights respond to an auditory
>>>> input. I'd like the lights to turn on in time with the sound of a
>>>> ventilator (a medical one). So when the ventilator is
>>>> not doing a breath, the lights would be off, but then when the
>>>> ventilator starts doing a breath they would
>>>> turn on for the duration of the breath. I'd like the lights to
>>>> up and dim gradually, not just on an off.
>>>> What's a simple or best way to do this?
>>>> Lab mailing list
>>>> Lab at artengine.ca
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