Graffiti Can

This project is tagged under: physicalcomputing

25 Nov 2011

Inspired by “Picasso’s Drawing with Light” we wanted to make something similar but instead of taking pictures, we would be using live video.

While Picasso used a slow shutter speed and a quick hand with a flashlight to create the images.

We used Arduino and Processing to create our own “graffiti can”. Initially we wanted to only use an accelerometer to track the movement on the screen but that proved to be very challenging since there was a a lot of computational math involved in converting the acceleration of the sensor to actual X and Y points on the screen. After consulting ITP Resident Researcher Greg Borenstein he suggested that we should just track a light pointed at the camera in processing to create the images instead of the accelerometer. This was a last minute code change which changed our approach completely. But using examples in processing, it shortened the time to build the code.

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Here we are building the code and can at the same time.

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Adria testing the serial connection.

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Serial input coming in.

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Wiring for the red can.

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We opted for a smaller breadboard to make things lighter and compact inside.

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This might have worked better in another manner, but I mounted the Arduino Uno and the breadboard back to back on a strip of corrugated cardboard to make things easier to dismantle and attach by just screwing them.

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One slight problem, the 9V power connector was sticking out. That was eventually rectified and it all fit in the can.

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I used alligator clips to be able to quickly attach and detach the board from the super bright LED if we had to make any changes.

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Getting the bluetooth to work was very tricky, because in order for the bluetooth to work, the BT chip must be disconnected while uploading the code for the Arduino and connecting it afterwards. The BT will not pair with the computer unless the sketch was running. It took a bit of wrangling but it eventually worked.

We became ambitious and worked on a second can.

We also started using an external USB camera to make the video resolution a bit better. But, like the BT it was a challenge to get these two to work as well.

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Adria here with last minute changes to can.

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Crunch time! Need to fit everything inside working!

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Red vs Blue

By pressing the top button like a spray can, the “paint” will be drawn over the image. An accelerometer using only the Z-axis due to the position of the can inside would save the current image and clear the screen.

The project was shown at the ITP Winter Show 2011.

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More graffiti pictures.

Built with Adria Navarro-Lopez, Veronika Dubrovskaya and Joseph McCagherty at ITP.