If You Own a Camera You Need to Try Light Graffiti

Do you have a camera that’s capable of controlling how long of an exposure it takes?  With this and any small light source, you can make a really awesome illuminated image like the one featured above.  Combine this with the hacking skills that you’ve hopefully learned from reading Hackaday, and the visual possibilities are endless.

Let’s look at the background of this entertaining light hacking technique, and how you can make images like this yourself!

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Four Meter Light Paintings


We’ve seen some light painting before – waving a microcontroller and LED strip in front of a camera is a very interesting project after all. [Saulius]’ light painting stick is unlike anything we’ve seen before, though. It’s huge – four meters high, and is also very flexible in the field, drawing images served up from a smart phone.

To get his pictures onto his light painting stick, [Saulius] used the very cool Carambola, an exceedingly small board that also runs Python. The images were converted to a 128xWhatever .BMP file served to the Carambola over WiFi with a smart phone, Since the Carambola runs Linux, sometimes a kernel interrupt would mistakenly restart the drawing process. [Saulius] found a way around that by writing the drawing code in C and wrapping that in a Python module. The speed of C and the flexibility of Python, who could ask for more.

On the project page, you can see [Saulius] pulling off some very cool light paintings. Even though the Hackaday logo is the best way to get on the front page here, this pic is probably the most impressive

Super-precise light painting from a delta robot


The points of those geometric shapes line up perfectly thanks to the delta robot arm controlling the light source. The source is a simple LED that can be switched on and off as it moves. A camera is set up in a dark room to keep the shutter open while the arm moves. We’re assuming that all of the light for the stationary objects in this image comes from the LED as well.

[Sick Sad] built the delta bot for just for this purpose. Check out the video below to see, and perhaps more importantly hear, the thing in motion. Seriously, the whine of the stepper motors is pretty awesome on this one.

The delta concept uses a central head on three arms angled down from above. If the LED is also pointed down it won’t light up the hardware and that’s why it doesn’t show up in the image. We’ve seen similar accuracy when using this style of machine for 3D printing. But if you don’t want to build a complicated machine you can try this out with a simple string plotter.

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Hackaday Links: Sunday, June 9th, 2013


This week we saw an interesting animated motorcycle tail light over on Reddit. But there wasn’t really enough background to get its own feature.

The NeuroKnitting project captures brainwaves by weaving them into a scarf.

On Semiconductor is showing off an 8x8x8 LED cube which they claim as 12,000 LEDs. We can’t figure out where all those LEDs are used in the design, but maybe you can. Here’s one that we know has 4096 LEDs in its matrix.

[Jeff] used hard drive platters as the disc section of his original Enterprise desk model.

Play around with an SNES controller and Arduino by following [Damon’s] guide.

Hackaday Alum [Jeremy Cook] posted an update of his laser graffiti project. His earlier effort used camera tricks to capture the image but this time around he’s exciting phosphorescent glow material to make a persistent display visible to the human eye.

This server hides in plain sight after being wrapped in a hard cover book binding. Hopefully this won’t cause heat dissipation problems.

[Trumpkin] built his own Nixie tube wristwatch which we think has the potential to be as neat as the one [Woz] wears.


Light Graffiti with Servos and Python


Light Graffiti is can be lots of fun if you have a decent amount of artistic ability, and a keen sense of timing. If you don’t have the necessary skills, you can always compensate by using Python-controlled servos to move everything automatically. The Python code can be found here, and makes use of the Python Image Library to process the images into a “drawable” form. A [pyMCU] with firmware capable of simultaneous servo control was used to move the laser fixture around.

One of the more difficult aspects of this experiment was getting the timing correct between each laser pulse. The timing routine involes a bit of geometry, calculating the distance between each using trig. As explained in the article, this may be a bit of overkill.  It still didn’t compare to the trig involved in a previous experiment drawing a circle with this laser-servo fixture.  Be sure to check out the video of this laser-setup in action after the break.  I’ve been quite pleased with the results, and look forward to what can be done with it in the future!

Thanks to [pyMCU] for letting me have a few of these boards to play with!

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LED fun and Light Painting with the pyMCU


Recently [Richard] at [pyMCU] was nice enough to send me one of their units to try out. As featured here before, this little board allows you to control physical things using your computer and the Python programming language. After evaluating it and making a LED blink, there were a couple other LED projects I wanted to try.

The first idea was to make a LED chaser. This was quite simple, using a little code and plugging in a few LEDs. From this, since you can make the LEDs chase each other, then in the right sequence it should be able to be used to display images using long-exposure photography. Be sure to check out the video after the break of this 10 LED chaser/light bar being assembled.

The results of this LED light bar experiment were really cool, writing some simple text and image with 10 LEDs. Considering the low component count, this is one of the simplest light bar builds that we’ve seen. Programming was simple as well, since the computer using Python does all the processing of the drawing as well as physically turning the LEDs on and off. Of course this setup isn’t without its limitations, having to be connected to a computer being the most obvious. Continue reading “LED fun and Light Painting with the pyMCU”

LED wand brings ergonomics to light painting

Quit struggling with hastily patched together electronics for your light painting images. Follow [Madox’s] example and build a light painting wand designed with your hand in mind.

You wield it much like a sword, but the only damage it does is to the long-exposure camera pointed its way. The RGB LED strip is controlled by the guts of a tiny little wireless router, a TP-Link TL-WR703N. This lets [Madox] connect using an Android device to upload different images. It also lets you tweak the settings like adjusting the timing between columns to match your exposure settings. The custom handle design provides a home and mounting plan for everything involved. It was 3D printed at the Sydney Hackerspace.

This isn’t the first light painting device running Linux. We’ve actually seen the Raspberry Pi used in much the same way but that final project involved using an entire recumbent tricycle to move the colored lights.