Hackaday Links: February 9, 2014

hackaday-links-chain

Here’s a quick tip to extend the usefulness of your multimeter. It’s a set of mini test hooks soldered to alligator clips with a short hunk of stranded wire in between. You can buy mini test hooks that go right on the metal probes of your meter, but the weight and bulk of the meter probes and cords sometimes get in the way. This rig allows more flexibility because of that wire.

Staying on the theme of test equipment tips, here’s a simple way to make a Y-connector for logic analyzers. [Thomas] uses a dual-row pin header, shorting each pair of pins so that both rows are connected. When this is plugged into a pin socket it leave two pins for connecting your test equipment and the rest of the project hardware.

After seeing our feature of a 3-wire Character LCD [Chad] wrote in to mention he built a 1-wire version using an ATmega328.

If you’re going to be in Anaheim this week you can stop by the ATX-West expo and see a 3D printer with a 1m x 1m x 0.5m printing area. [Thanks Martin]

Speaking of 3D printers, here’s a big delta robot (seven feet tall) outfitted for alternative material printing. It’s printing a CT scan of ribs and a heart in hot glue. This seems to be a popular material for more artistic uses. We just saw a hexapod which deposits hot glue as it roams.

The weaponized quadcopter post from Tuesday was a controversial one. The really bad part of it was the laser, which strapped to anything is extremely dangerous. But the other hack may have just been poorly executed. Hackaday alum [Jeremy Cook] wrote in to mention that fireworks and quadcopters can be used more responsibly. He strapped a sparkler to his quadro and used it to make light graffiti. You may remember that [Jeremy] wrote an introduction to light graffiti for us back in November.

I Am the Midnight Message Board What Messages at Midnight

Photoluminescent stars on your bedroom wall or ceiling are pretty cool, though the stationary shapes can become boring. [Adi] felt this way, too. While doodling with a bright white light on some glow in the dark vinyl, it occurred to him that this could make for an interesting display. He set about making GLO, the midnight message board and RSS display.

[Adi]’s light writer uses 12 UV LEDs on a linear axis powered by a stepper motor to write RSS headlines, Twitter trends, or custom text on his wall. He finds the slow fade of the text very soothing to fall asleep by, and it’s easy to see why. The LED array imprints a section of a character consisting of a 6×5 bit pattern. The 12 LEDs are split into two groups, so it can write two lines at 45-50 characters each. [Adi] designed his own pixel font for this project, and advises that only upper case letter forms be used.

[Adi]’s write-up is quite admirable and comprehensive. In the circuit build section, he advises that the LEDs must be very close to the vinyl for optimum results, but that they should protrude farther than the shift registers so the chips don’t rub the vinyl. Of course you could opt for more intense light sources, like laser. See it in action after the break.

Continue reading “I Am the Midnight Message Board What Messages at Midnight”

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!

Continue reading “If You Own a Camera You Need to Try Light Graffiti”

Light Graffiti with Servos and Python

servo-laser-light-graffiti

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!

Continue reading “Light Graffiti with Servos and Python”

LED fun and Light Painting with the pyMCU

pymcu-led-pov-writing

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”