Light Painting is an photographic technique which is made by taking a long exposure photograph on moving handheld sources of light. There are several problems with this approach:
- There is no feedback system. The artist is unable to see exactly what they're drawing
- There is a limited amount of time to take a long exposure shot, and on top of that there are no room for mistakes
- It's a difficult technique; creating complex art requires practice and skill
- All artwork made with conventional light painting techniques seem hand-drawn. It looks like someone just drew their artwork with a marker
What it does
So in traditional light painting the artist just sets the camera to long exposure and waves a flashlight around at it to create their artwork. So, what if you had 288 LEDs on a two meter long stick? One can upload an image to this stick, then hold it upright, and as they move it through 3D space, the stick scans through the image and shoots out each column of pixels in light. It's essentially a 3D light printer.
How We built it
We used a Raspberry Pi 3, a two-meter-long strip of 288-LED tape we soldered together, a breadboard, and various electrical components for our circuits. The Raspberry Pi intakes images through a USB drive and processes them with code in Python and C.
Challenges We ran into
Due to the nature of the hack and how we were building custom circuits for it, we were not able to afford any mistakes in our circuitry because that could potentially damage the Raspberry Pi or the LED tape or any other of the irreplaceable components we used. A lot of these components are expensive and thus any error could be very very very very very catastrophic. As a result, precision soldering and an insane amount of testing/sanity-checking was of upmost importance. We would test a circuit a couple times before soldering/assembling, then test it a couple times while soldering, and then test it three times after soldering.
Accomplishments that we're proud of
What I learned
One of our member who rarely do hardware projects learned about connecting circuits, how to use a soldering iron, and how to connect hardware to the raspberry Pi. As a team we also learned how to do hardware unit and integration testing for hardware.
What's next for Project Firefly
We are thinking of using a bigger stick or smaller LEDs for higher resolution picture. We are also thinking of mounting a small camera on the stick to record video while taking pictures.