Philip Friedin Takes Us On A Deep Dive Into His OSHChip

March 8, 2016 by Sonya Vasquez 33 Comments

Once a month, Bay-area hackers and engineers-by-night gather in the grand office of our evil overlords (Supplyframe) and take us on an adventure in hardware. This past month, [Philip Friedin] gave us the hands-on tour of the OSHChip, a project we’ve seen floating around our pages for the last year. OSHChip might look like another open source development board, but the DIP package and all the packaged features are telltale signs that OSHChip is the offspring of a seasoned double-E. Scroll down to watch his presentation in full.

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How Low Can You Go? The World Of QRP Operation

March 8, 2016 by Dan Maloney 52 Comments

Newly minted hams like me generally find themselves asking, “What now?” after getting their tickets. Amateur radio has a lot of different sub-disciplines, ranging from volunteering for public service gigs to contesting, the closest thing the hobby has to a full-contact sport. But as I explore my options in the world of ham radio, I keep coming back to the one discipline that seems like the purest technical expression of the art and science of radio communication – low-power operation, or what’s known to hams as QRP. With QRP you can literally talk with someone across the planet on less power than it takes to run a night-light using a radio you built in an Altoids tin. Now that’s a challenge I can sink my teeth into.

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Game Boy Camera Cartridge Reversed, Photos Dumped

March 8, 2016 by Elliot Williams 12 Comments

There’s something magical and nostalgic about extremely low resolution in this era of mega-megapixels on every cell phone. And the Game Boy’s big bulbous camera module just looks so cool. [Robson Couto] didn’t stop at simply using the camera — that’s been done before — but actually reversed the card’s protocol so that he could leave it entirely intact. As you can see from the banner image, it was a success.

A project like this doesn’t get done overnight, and [Robson] drew on a lot of his own previous work as well as the work of others. For instance, he’d already made a board that interfaces Game Boy Paks to his PC through an ATmega32 and a serial port. He’d also written software that understands the card header format on the PC side. So dumping the ROMs contents should be no problem. But of course, it was.

[Robson] could read one bank of memory, but not any of the others. It turns out that the camera pack uses a clock signal that not many other cards use. It took [Robson] some serious work — a lot of it false starts and dead ends — to get this particular part working.

If you’re into Game Boy hacking, give [Robson]’s writeup a good read. Also note that he’s got fantastic links to previous research in all of his posts. If you couldn’t care less about keeping the cartridge intact, you can simply interface the camera with a TI calculator, use the camera to transmit Morse code, or simply add a thermal printer for a low-res instant camera with style.

Thanks For The Memories: Touring The Awesome Random Access Of Old

March 8, 2016 by Al Williams 41 Comments

I was buying a new laptop the other day and had to make a choice between 4GB of memory and 8. I can remember how big a deal it was when a TRS-80 went from 4K (that’s .000004 GB, if you are counting) to 48K. Today just about all RAM (at least in PCs) is dynamic–it relies on tiny capacitors to hold a charge. The downside to that is that the RAM is unavailable sometimes while the capacitors get refreshed. The upside is you can inexpensively pack lots of bits into a small area. All of the common memory you plug into a PC motherboard–DDR, DDR2, SDRAM, RDRAM, and so on–are types of dynamic memory.

The other kind of common RAM you see is static. This is more or less an array of flip flops. They don’t require refreshing, but a static RAM cell is much larger than an equivalent bit of dynamic memory, so static memory is much less dense than dynamic. Static RAM lives in your PC, too, as cache memory where speed is important.

For now, at least, these two types of RAM technology dominate the market for fast random access read/write memory. Sure, there are a few new technologies that could gain wider usage. There’s also things like flash memory that are useful, but can’t displace regular RAM because of speed, durability, or complex write cycles. However, computers didn’t always use static and dynamic RAM. In fact, they are relatively newcomers to the scene. What did early computers use for fast read/write storage?

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Ask Hackaday: Is PLA Biodegradable?

March 8, 2016 by Brian Benchoff 79 Comments

The most popular plastic for 3D printers is PLA – polylactic acid – a plastic that’s either derived from corn starch, inedible plant detritus, or sugar cane, depending where in the world it was manufactured. Being derived from natural materials, PLA is marketed as being biodegradable. You don’t need to worry about low-poly Pokemon and other plastic trinkets filling landfills when you’re printing with PLA, all these plastic baubles will return to the Earth from whence it came.

3D printers have been around for a few years now, and now objects printed in PLA have been around the sun a few times. A few of these objects have been completely forgotten. How’s that claim of being biodegradable holding up? The results are mixed, and as always, more data is needed.

A few weeks ago, [LazyGecko] found one of his first experiments in 3D printing. In 2012, he was experimenting with tie dying PLA prints by putting his prints in a jar filled with water and blue dye. This jar was then placed in the back of his cupboard and quickly forgotten. 3.5 years later, [LazyGecko] remembered his experiment. Absolutely nothing happened, save for a little bit of blue dye turning the print a pastel baby blue. The print looks and feels exactly like the day it came off the printer.

[LazyGecko]’s blog post was noticed by [Bill Waters], and he has one datum that points to PLA being biodegradable. In 2015, [Bill] printed a filter basket for his fish tank. The first filter basket worked well, but made a small design change a week later, printed out another, and put the first print in storage. He now has two nearly identical prints, one in constant use in a biologically interesting environment, the other sitting on a shelf for a year.

[Bill]’s inadvertent experiment is very close to the best possible experimental design to make the case for PLA biodegradability. The 3D printed filter basket in constant use for a year suffered significant breakdown, and the honeycomb walls are starting to crumble. The ‘inert’ printed filter basket looks like it just came off the build plate.

If that’s not confusing enough, [Bill] also has another print that has spent a year in a fish tank. This end cap for a filter spray bar didn’t see any degradation, despite being underwater in a biologically active environment. The environment is a little different from a filter basket, though; an aquarium filter is designed to break down organics.

To answer the question, ‘is PLA biodegradable,’ the most accurate answer is, ‘maybe’. Three data points in uncontrolled environments isn’t enough to draw any conclusions. There are, undoubtedly, more forgotten 3D prints out there, and more data to back up the claim of PLA being biodegradable.

This is where you come in. Do you have some forgotten prints out there? Your input is needed, the fruits of your labors are evidence, your prints might be decaying and we want to know about it below.

Wall-E Goes Corporate, Offering Telepresence Service

March 8, 2016 by Richard Baguley 4 Comments

I guess if you are going to build a robot to do something boring like telepresence, you might as well make it cute. That’s obviously what [Andrew Maurer] was thinking when he built a telepresence robot using a Wall-E toy. The result is kind of adorable: Wall-E is holding the 5-inch HDMI screen that shows the video, and can scoot around in true Pixar fashion under remote control.

It’s also a neat build on the inside, using a Raspberry Pi for the brains and an Adafruit MotorHat to control the motors. The original toy didn’t have motors, so he added a new RC gearbox and motors to drive the little fella around. Installed behind Wall-Es eye is a USB webcam. Running behind the scenes is a mumble server that does the audio, a copy of Chromium that shows the video, and an Apache server that feeds the captured video to the other end of the conversation. The whole thing is tied together by a few scripts that kick things off appropriately and allow the user to remotely control Wall-E. It’s a cute build, and hopefully Wall-E can still find his EVE while performing his new corporate duties.

[via reddit]

Geodesic Dome Build At Rev Space Den Haag

March 7, 2016 by Jenny List 24 Comments

[Morphje] has always wanted to build a geodesic dome. The shape and design, and the possibility of building one with basic materials interest him. So with the help of a few friends to erect the finished dome, he set about realising his ambition by building a 9.1 metre diameter structure.

The action took place at Rev Space (Dutch language site), the hackspace in The Hague, Netherlands. [Morphje] first had to create a huge number of wooden struts, each with a piece of tube hammered down to a flat lug set in each end, and with a collar on the outside of the strut to prevent it from splitting. The action of flattening the ends of hundreds of pieces of tube is a fairly simple process if you own a hefty fly press with the correct tooling set up in it, but [Morphje] didn’t have that luxury, and had to hammer each one flat by hand.

The struts are then bolted together by those flattened tube lugs into triangular sections, and those triangles are further bolted together into the final dome. Or that’s the theory. In the video below you can see they make an aborted start assembling the dome from the outside inwards, before changing tack to assemble it from the roof downwards.

This project is still a work-in-progress, [Morphje] has only assembled the frame of the dome and it has no covering or door as yet. But it’s still a build worth following, and we look forward to seeing the finished dome at one or other of the European maker events in the summer.

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