Year: 2011

Hackaday Links: December 25, 2011

December 25, 2011 by 13 Comments

Ah, Christmas. That wonderful time of year when you can roll out of bed to the screams and wails of children, grab a hot cocoa, and spend several hours arguing with an 8-year-old about which LEGO set to build first. Simply magical. While you’re waiting for the Doctor Who Christmas special to come on, settle down with these wonderful Christmas-themed builds that came in over the last few weeks.

One step closer to Robot Santa

Here’s an interesting way to spice up your seasonal headwear. [Mark] took a Santa hat and added a string of multicolored LEDs to the brim. The lights were picked up at a drug store for a dollar. Control is through a simple push button connected to an ATtiny13. Press the button, the lights cycle in a different pattern. Very cool, so check out the video.

A holographic holiday tree

[Auger] posted this very cool light up Christmas tree decoration on Instructables. This tree is made up of three pieces of acrylic. Different designs were laser cut into each piece of plastic – candy canes for the ‘red’ piece, stars and tinsel for the ‘yellow’ piece, and the tree for the ‘green’ piece. LEDs of the respective colors are cemented to the bottom of each bit of plastic. It’s called light piping and is used everywhere. This is the first time we’ve seen three colors, though.

This is what nerds do, and it’s awesome

[Rickard Dahlstrand] was playing around with his phone trying to take deliberately fuzzy pictures of his tree. He noticed the dashes produced from the LED Christmas lights must be produced from PCM dimming. Going through the EXIF data in the picture, he found the exposure time was 1/17th of a second. 1/17 of a second = ~ 58 ms / 5 (cycles on the picture) = ~11 ms per cycle = ~100 Hz frequency on the PCM dimming. Of course this is just about 2 times the line frequency in [Rickard]’s native Sweden, so we’ll call this confirmed. There’s no blog post for this, but we’ve never seen a clearer example of applied geekery. Simply awesome.

Yeah, we measured [Rickard] on a nerd meter

In the spirit of giving, [Johannes] decided to tell the entire world exactly how nerdy he is. He built a ‘Nerd Alert’ meter out of an old 1950s Japanese multimeter. The old guts of the meter were chucked, and a simple amp made out of a transistor amplifies the current flowing through the user’s fingers. A neat scale ([Johannes] measures somewhere between Amiga Workbench and Space invaders) replaces the old, boring, number-based one. Again, no write-up, but here’s some awesome build pictures.

Finally a use for all those old radio tubes

[AUTUIN] took apart a vacuum tube with a blow torch and a diamond cutting wheel. Surprisingly, he was able to put it back together, but not before making a wonderful Christmas ornament. There are two copper wires inside the envelope that are the leads to a single orange-red LED. The whole thing is powered by a watch battery. We’ll be sure to reference [AUTUIN] next time we have to take apart a glass bulb, because he managed not to burn, cut or blind himself.

Six things in a links post? It’s a Christmas miracle!

[Darryl] sent in a nice tool to select and display all of the hacker/maker merit badges available from Adafruit. Oh, we’re still trying to figure out who to give 10 badges to. We’re giving away skull ‘n wrench badges to the top ten hacks ever featured here. Leave a note in the comments, or tell us who should win.

Holiday wishes

Now put the computer down and go spend some time with your families, or failing that, strangers. Of course there’s an all day Doctor Who marathon, and that thing isn’t going to watch itself…

Reduced-cost Braille Display For Use With Computers

December 24, 2011 by 12 Comments

Apparently a Braille computer display can cost several thousand dollars. That’s why [David Pankhurst] is working on a low-cost alternative. His offering is an open source version he calls the Audrey Braille Display.

The concept is quite good. This prototype has one line of six Braille characters. Each character is made of two sliding strips containing eight arrangements of bumps. These can make up any character when positioned correctly. Two motors do all the work, one engages a single strip to reposition it, the other moves the first motor to select which strip should move. This is explained quite well in [David’s] most recent post. Or you can get a preview of the physical build here.

The concept is sound, but the refresh rate must be very slow. We wonder if there’s a way to keep one motor stationary and use solenoids to engage a drive shaft on the individual slide rods? This way, every row could be changed at the same time, disengaging when the appropriate slot is reached.

This hardware is much needed until developing Braille technologies actually come to market.

[via Dangerous Prototypes]

We’re On An Atari Jaguar Kick, Apparently

December 24, 2011 by 11 Comments

We don’t know why, but the Atari Jaguar is getting a lot of attention this week. [10P6] just came up with this Jaguar/CD combo that reminds us what Atari could have come up with in 1993.

The build itself is relatively simple once you get past [kevincal]’s ‘April Fools’ type joke he played on the Atari Age forum. [10P6] took a regular Jaguar CD drive and cut a hole into a Jaguar case. The whole case mod took less than a three hours, but [10P6] gives us a lot of commentary into what Atari could and/or should have built in 1993.

[10P6] suggests this type of Jaguar would have saved Atari money if the CD drive was stock on the base unit and released at a slightly increased price. This would cut out the cost of the cart slots and reduced the amount of plastic in manufacturing. [10P6] also talks about how Atari engineers could have dropped the 68000 coprocessor with an increase in the system clock. We’re not quite fond of that idea (ask us about our tattoo), but the logic does make sense.

Of course, this build comes on the heels of the Jaguar Portable we saw a few days ago. Honestly, we have no idea what’s going on with the Jaguar build.

DIY Solution Does PoE On The Cheap

December 24, 2011 by 23 Comments

diy-poe

Depending on the scope of your requirements, Power over Ethernet (PoE) components can get pretty pricey. [Fire] wrote in to share a 4-port PoE solution he put together for under 20 euros (Ignore any SSL errors – we’ve checked it out, it’s safe).

The most expensive part of the build was the 8-port patch panel he purchased for 11 euros. He popped it open, wiring the first four ports for power after drilling spots for an indicator LED and the PSU. He wound the power lines through ferrite beads to hoping to dampen any interference that might occur before reassembling the panel.

In the picture above, you might notice that the panel is being powered via the first Ethernet port rather than through the barrel jack, which [Fire] said was done for testing purposes. When deployed in his network, he plans on using a regulated power supply from a junked laptop to provide electricity.

If you need to provide PoE to devices on your network, this is a great way to go about it. Using a patch panel like [Fire] has gives you the flexibility to easily wire up as many powered ports as you need without much hassle.

Digital Synth For The Non-chiptune Inclined

December 24, 2011 by 5 Comments

Chiptunes are great, and we can’t imagine a world without the Mega Man 2 soundtrack, but sometimes we all like a more 70’s style synth. This is where the Roninsynth steps in. It’s an Arduino shield that puts the basic components of a wall of synth into your pocket.

Unlike the analog oscillators of yore, the Roninsynth is based on a single dsPIC33F chip. It has all the waveforms we would expect from its big brother – sine, saw, triangle, square, and noise – and a couple modulation options.  What’s really interesting is the GUI the Roninsynth team put together. Instead of going with the knobs and buttons approach of the MIDIbox SID, the Roninsynth does everything with software. Think of it as a hardware-based softsynth.

Of course, there isn’t support for looping and phrases like what we saw yesterday, but there’s a ton of neat sounds that can be made and the capability for analog input. If you’ve ever wanted to sound like Radiohead, we can’t think of an easier way to build an Ondes Martenot.

[Scot] Whips Up Breakout Board For His ARM Breakout Board

December 23, 2011 by 10 Comments

[Scot Kornak] got his hands on the new STM32 Discovery Board. He got his as a free giveaway, but at only $18 he probably would have picked one up anyway. His one complaint about the device is that he dual pin-headers which break out the ARM processor’s pins are not the most convenient for hooking up external components. He decided to make his own breakout board which would give him a more robust solution for the components he uses all the time.

The protoboard that he chose as a base is quite interesting. It’s made for interfacing DIL pin headers just like the ones on the STM32F4 Discovery board. Each row of the dual header is carried down the board perpendicular to those headers. [Scot] cut the traces underneath the STM32 board to isolate the right and left sides. He then added RS232 hardware to one side, while including another pair of DIL headers to break out the rest of the unused pins.

This is all he’s got so far, but there’s plenty of room on the base board to add more as the need arises.

A Vacuum Chamber From A Pressure Cooker

December 23, 2011 by 36 Comments

[Allan] needed a small vacuum chamber to get all the air out of clear casting resin. Degassing is a simple step in casting that improves the finished product immensely. The problem, though, is building a vacuum chamber. [Allan]’s chamber seems easy enough to build, and pulls enough air out to get to 0.1 atmospheres.

After a hole was drilled in the side of the pressure cooker, [Allan] installed a 15mm “speedfit” plastic tank connector. The seal around the connector is neoprene self-adhesive foam. This foam was also taped around the lip of the pressure cooker for the top.

A thick-walled pressure cooker is more than capable of handling the outside pressure when under vacuum, but [Allan] cautions against using acrylic plastic for the top. Acrylic has the tendency to fail catastrophically, so he used a thick sheet of Lexan. Check out the demo video of [Allan] sucking the air out of shaving cream after the break.

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