Via Raspihub Via Design Spark.
Earlier this year I was offered the opportunity to put on an installation in an amazing space – the old ice wells under the London Canal Museum. Although visitors cannot normally go down into the wells, they can be viewed from a balcony in the museum. Having created a low light installation recently, these dark wells offered me a chance develop these ideas further.
One interesting thing about the ice wells was that they were originally much deeper. But after the second world war they were used dump rubble in during the clear up from the Blitz. I started to think about the idea of some odd, even alien, technological relic being buried down there, collecting information for some unguessable purpose. Working with this idea would give me the opportunity to create a show that responds to viewer some way, and I’d able to incorporate the new technologies I’ve been playing with.
So, I had a starting point for the installation, but then the sheer logistical complexity and constraints of project started to hit me. Any technology that I used would need to be capable of being started up and shut down by the museum staff, doing nothing more complex than pressing an on or off switch. It would also have to operate for 7 hours a day, 6 days a week without crashing. Any work in the ice well would only be seen from about 4m above, so would have to be bright and large enough to be visible at that distance, or be very cleverly lit. Anything installed down there needs to be lowered using a pulley system. And of course there was no way I could test anything in situ until my two setup days. By which time it would be way too late to make any significant changes.
I revised my initially over ambitious ideas accordingly and decided that one of the best ways to fill the well, simply and dramatically, was to put some kind of surface down there and project onto it.
In a recent show I did a piece where the viewer was subtly captured on a webcam and incorporated into the image displayed. If I wanted to do that, I needed to get people close enough to the camera capture recognisable faces. I came up with the idea of using a display case. I could display a piece of work as though it was an exhibit in the museum, and capture images while people were looking at it.
RS Components generously supplied me with some components for installation, including a Raspberry Pi and a picamera which I could use as a webcam. At this stage I roped in a developer friend to help me. I wanted to capture a slow ghostly image that would appear and fade over time. I didn’t want anything too obvious and the time lapse meant that someone could look at the display with the camera in, and then down into the well and still see their face. The software that my friend developed captured periodic images and superimposed each one onto a composite of the previous images.
I performed a couple of sessions of stress testing with the pi running the software and outputting through projector. Thankfully everything performed as hoped. The pi was impressively stable, not crashing once during the sessions.
So now I have everything set up and ready to install. We have one day to set everything up while the museum closed, then another day for tweaking if necessary (although with an audience of museum visitors!).
The installation opens officially at the London Canal Museum on 20th August and closes on 14 September. If you’re in London and would like to take a look, the details are on the show website.
Further details about my project including the Python code used, can be found on my Tumblr page.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
