Spell Out The Time With Frickin’ Laser Beams

Clocks are a never-ending source of fascination to hackers. We get all kinds around here, from Steampunk Nixie clocks to retro cool flip clocks to clocks that don’t even look like clocks. But this is something new — a glow-in-the-dark laser tracing clock.

What [tuckershannon]’s clock lacks in practicality it makes up for in the gee-whiz department. The idea is simple: trace the characters out on a phosphorescent screen using a laser. To accomplish this, [tuckershannon] adapted the design of this whiteboard marker robot clock, replacing the drawing surface with glow-in-the-dark stickers. A 405 nm laser diode module is traced over the surface by the two-servo pantograph plotter, charging up the phosphors. He offers no clue as to how long the ghostly image lingers, but from the look of it, we’d bet that it lasts for a good fraction of a minute, especially in a dark room. Then again, you’d want the image totally faded before the next write cycle comes up, to prevent overwriting the previous time.

All in all, it’s a nice design and a clever new clock display modality. And who knows — maybe this whole glowing phosphor display thing could really catch on.

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Save Your Thumbs With This Netflix Password Sender

Chances are anyone who has an entry-level to mid-range smart TV knows that setting them up with your streaming account credentials is a royal pain. Akin to the days of texting on a flip phone, using the number pad or arrow keys to compose your user name and password seems to take forever.  So why not avoid the issue with this automated Netflix logger-inner?

As if the initial setup wasn’t bad enough, when [krucho5]’s LG smart TV started asking for his Netflix credentials every few days, he knew something needed to be done. An Arduino to send “keystrokes” was the obvious solution, but when initial attempts to spoof the HID on the set proved fruitless, [krucho5] turned to the IR remote interface. He used an IR receiver module to capture the codes sent while entering user name and password, and an IR LED plays it back anytime the TV ask for it. The video below shows how much easier it is now, and the method should work just fine for any other online service accounts.

We like [krucho5]’s build, but the fit and finish are a little rough. Perhaps slipping them into a pair of Netflix-enabled socks would be a nice touch?

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Hackaday Prize Entry: A Manual, CNC Pick And Place Machine

Everyone who wants a 3D printer probably already has one, and even laser cutters and CNC machines are making their way into garages and basements ’round the world. Pick and place machines are the next great frontier of personal manufacturing, and even though that’s a long way off, [Tegwyn]’s project for this year’s Hackaday Prize is bringing us that much closer to popping down 0201 LEDs reliably.

This project is a manual pick and place machine — otherwise known as ‘tweezers’. It’s a bit more complicated than that, because the entire idea behind [Tegwyn]’s build is to decouple a human’s fine motor skills from the ability to place components on a board. To do that, this project is using an off-the-shelf, blue light special CNC machine. There’s not much to it, just a bit of aluminum extrusion and some threaded rods. However, with the addition of a vacuum pump, a hollow needle, and a few manual controls to move the axes around, the operator has very fine control over where a resistor, cap, or LED goes.

There are a few neat additions to the, ‘put a vacuum pump on a CNC machine’ idea. This is a 4 axis machine, giving the user the ability to rotate the part around a pad. There’s also a microscope hooked up to a small monitor mounted to the machine. If you’re assembling hundreds of boards, this is not the machine you want. If, however, you only need a handful, don’t mind spending a few hours placing parts, and don’t want to go insane with tiny QFN packages, this is a great build and a great entry for the Hackaday Prize.

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Ourselves As Others See Us Through The Lens Of Traditional Media

When I presented myself at the SHACamp 2017 info desk bright and early on the first full day of the camp, I was surprised to find that I was to be assigned a volunteer along with my press badge. Because of the way our community is sometimes covered by the traditional media, it was necessary that any journalists touring the site have a helping hand to ensure that they respect the privacy of the attendees, gain permission from people likely to be in any photographs, and generally not be idiots about the whole Hacker thing. I pointed out that I was working for Hackaday and not The Sun, and that as an active hackspace member and former hackspace director I was very much a part of the community attending SHA 2017 who would simply be wasting the valuable time of any volunteer assigned to me. Fortunately for the next volunteer in line they agreed with my point of view, so one of the angels was spared a day of my breakneck walking pace and impenetrable British colloquialisms.

It’s interesting therefore a few weeks after the event, to investigate how it was portrayed through the eyes of people who aren’t coming as Hackaday is, from within the bubble. To take a look at that disconnect between what we know about our community and its events, and how the traditional media sometimes like to portray us. Are they imagining the set of a Hollywood “hacker” movie in which assorted geniuses penetrate the computer systems of various international institutions by the simple expedient of banging wildly at a keyboard for a few seconds, or will the reality of a bunch of like-minded technology enthusiasts gathering in a field for several days of tinkering and other fun activities be what makes their reports?

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A Diode By Any Other Name

As active devices go, it doesn’t get much simpler than a diode. Two terminals. Current flows in one direction and not in the other. Simple, right? Well, then there are examples with useful side effects like light emitting diodes. [GreatScott] points out that there are other useful diodes and, in particular, he posted a video covering Schottky and Zener diodes.

These special diodes have particular purposes. A Schottky diode has a very low voltage drop and fast switching speed. Zener diodes have application in simple voltage regulation.

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Control Thy LED

In a previous article, I discussed LEDs in general and their properties. In this write-up, I want to give some examples of driving LEDs and comparing a few of the most commonly used methods. There is no “one size fits all” but I will try and generalize as much as possible. The idea is to be able to effectively control the brightness of the LED and prolong their life while doing it. An efficient driver can make all the difference if you plan to deploy them for the long-haul. Let’s take a look at the problem and then discuss the solutions. Continue reading “Control Thy LED”

Color Sensor From An RGB LED And A Photocell

When you need to quantify the color of an object, you’ve got quite a few options. You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to basics and build this reflective RGB sensor from an LED and a photocell.

The principle behind [TechMartian]’s approach is simplicity itself: shine different colored lights on an object and measure how much light it reflects. If you know the red, green, and blue components of the light that correspond to maximum reflectance, then you know the color of the object. Their sensor uses a four-lead RGB LED, but we suppose a Neopixel could be used as well. The photosensor is a simple cadmium sulfide cell, which measures the intensity of light bouncing back from an object as an Arduino drives the LED through all possible colors with PWM signals. The sensor needs to be white balanced before use but seems to give sensible results in the video below. One imagines that a microcontroller-free design would be possible too, with 555s sweeping the PWN signals and op-amps taking care of detection.

And what’s the natural endpoint for a good RGB sensor? A candy sorter, or course, of which we have many examples, from the sleek and polished to the slightly more hackish.

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