The Possibility Of Driving 16,000 RGB LEDs

April 16, 2015 by Brian Benchoff 17 Comments

Like just about everyone we know, [Luis] decided a gigantic RGB LED matrix would be a cool thing to build. Gigantic LED matrices are very hard to build, though: not only do you have to deal with large power requirements and the inevitable problems of overheating, you also need to drive a boat load of LEDs. This is not easy.

[Luis] found a solution to the problem of driving these LEDs with a new, fancy ARM Cortex M4 microcontroller. All Cortex M4 ARMs have DMA, making automatic memory transfers to peripherals and LED strips a breeze.

The microcontroler [Luis] is using only supports 1024 transfers per transfer set, equating to a maximum of 14 LEDs per transfer. This problem can be fixed by using the ping-pong mode in the DMA controller by switching between data structures for every DMA request. Basically, he’s extending the number of LEDs is just switching between two regions of memory and setting up the DMA transfer.

The result is much better than [Luis]’ original circuit that was just a bunch of SPI lines. It also looks really good, judging by the video below. It’s not quite a gigantic LED matrix yet, but if you want to see what that would look like, check out the huge 6 by 4 foot matrix hanging in the Hackaday overlord office.

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RadioShack Demise Could Signal The Rise Of Mom-and-Pop

April 16, 2015 by Mike Szczys 103 Comments

No matter how you feel about RadioShack, for many hackers it was the one place that components could be sourced locally. Upon hearing that the stores are being shuttered (at least for those seeking non-cellphone items) we wondered if someone would rise to meet the maker market. The answer may actually be mom-and-pops — independent stores owned by people passionate about hacking and making.

At SXSW Create in March the Hackaday booth was right next door one such establishment. [Martin Bogomolni] is hard at work launching his brick and mortar store called Tinker & Twist. In the video below he speaks briefly about the concept of the store, which focuses on curating the best products and tools available and stocking them locally.

The store will be located in a shopping mall in Austin, Texas. But it takes about 100 days launch a storefront considering the permits and build-out. [Martin] decided to take the store to the hackers by exhibiting (and selling products) at SXSW Create. How else would you do this than by building a store-front as your booth? The store’s sign was CNC routed from rigid foam, and combined with a set of columns and storefront window. We stopped by late on the last day of the event and they had been having a great weekend. What started as a very well stocked set of shelves looked nearly bare.

Tinker & Twist is just the most recent in a growing trend of standalone stores focusing on hackers and makers. Our friends at Deezmaker in Pasadena, CA gave us tour last year. They’ve married the concepts of hackerspace, small-run manufacturer (in the form of their 3D printers), and retail store all-in-one. These types of examples make us quite happy — it’s been years since RadioShack was tightly focused on those actually building things. We hope to see more stores like Tinker & Twist up and running to support and enhance hacker communities everywhere.

We Have A Problem: Health Care Where There Are No Health Care Workers

April 16, 2015 by Mike Szczys 46 Comments

Hackaday, we have a problem. There are a lot of people on this earth and not a lot of health care workers. Let’s use our skills to help alleviate this problem. What can we do to give medical professionals a wider reach, to bridge the distances between hospital and patient, and make it easier for bystanders to administer lifesaving care.

Scope of the Problem

We’d wager that your most recent and vivid remembrance of a health care worker shortage is the Ebola outbreak in West Africa. The shortage of trained professionals and supplies certainly compounded the situation in the countries worst hit. But it didn’t create the problem. Check out this list of doctors per 1,000 people (sorted lowest-to-highest with 2010 numbers). The three countries hit hardest by the outbreak — Guinea, Liberia, and Sierra Leone — register a whopping 0.0 doctors for every 1000 people. Yeah, that’s years before the outbreak.

Keep scrolling down and you’ll see that this isn’t limited to one geographic location. All over the world there are low numbers, with India and Iraq both at 0.6, and interestingly Cuba and Qatar topping the list at 6.7 and 7.7 respectively.

This isn’t a statistics post so let’s pivot. The point is made that we’re a large world population. What kind of engineering solutions can we wield to help provide everyone with the care they need? Leave your comments below but also considered entering the Hackaday Prize with them. Write down your idea as a Hackaday.io project and tag it 2015 Hackaday Prize.

Proof That We Can Do This

It’s safe to say we’ve all seen engineering solve part of this problem already. Over the last decade, Automatic External Defibrillators have become ubiquitous. The life-saving hardware is designed to be used by non-doctors to save someone whose heart rhythms have become irregular. [Chris Nefcy] helped develop AEDs and one ended up saving his life. If that’s not proof that we can change the world with our builds we don’t know what is.

Pull on that thinking cap and jump into this conversation. What can we build? What problems need to be solved right now? Where should each of us be looking to make a difference in the availability of health care in the absence of the trained professionals?

The 2015 Hackaday Prize is sponsored by:

Bouncing A Ball With A Robot

April 16, 2015 by James Hobson 6 Comments

A fan of kinetic projects, [Jimmy Demello] threw together a pretty cool robot that can bounce a ball back and forth between its hand(s).

Made from scraps around the house, it consists of some wood, a piece of a fishing pole, chop sticks, a single servo motor, and of course an Arduino Uno. His original plan was to make [Claude Shannon]’s juggling robot, but this is as far as he’s gotten — so far anyway.

It bounces a 2cm ball-bearing twice before catching it and passing it back again. He thinks it would be an awesome project to scale up and use basketballs, and we’d have to agree.

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What Is This? A Computer For Ants!?

April 16, 2015 by James Hobson 68 Comments

How can we be expected to teach children use a computer if they can’t even see it? I don’t wanna hear your excuses! The computer has to be at least… three times bigger than this!

Developed by the University of Michigan, the Michigan Micro Mote (M3) is quite possibly the world’s tiniest computer. It’s about the size of a grain of rice.

The multi-layered PCB (shown after the break) features 7 layers of components, surrounded in epoxy for protection. Drawing only 2 nano Amps during standby, the computer can be powered by a 1 millimeter squared solar cell. It’s designed to be glued to a window for use. It’s capable of input data via sensors, the ability to process and store the data, and then output the data wirelessly. Its range is only 2 meters at the moment, but they hope to extend it to about 20 meters.

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Arduino Vs. Arduino: The Reseller’s Conundrum

April 15, 2015 by Brian Benchoff 64 Comments

Over the last few months, the internal struggles between the various founders of Arduino have come to a head. This began last November when Arduino SRL (the Italian version of an LLC) sued Arduino LLC for trademark infringement in Massachusetts District court. To assuage the hearts and minds of the maker community, Arduino SRL said they were the real Arduino by virtue of being the first ones to manufacture Arduino boards. A fork of the Arduino IDE by Arduino SRL – simply an update to the version number – was a ploy to further cement their position as the true developers of Arduino.

This is a mess, but not just for two organizations fighting over a trademark. If you’re selling Arduinos in your web store, which Arduino do you side with?

[Nate] from Sparkfun is answering that question with a non-answer.

Currently, Arduino SRL is the only source of Arduino Unos. Sparkfun will continue to buy Unos from SRL, but they’re not necessarily siding with Arduino SRL; people demand blue Arduinos with Italy silkscreened on the board, and Sparkfun is more than happy to supply these.

There are, however, questions about the future of Arduino hardware. The Arduino software stack will surely be around in a year, but anyone that will be purchasing thousands of little blue boards over the next year is understandably nervous.

This isn’t the first time Sparkfun has faced a challenge in Arduino supply. In 2012, when the Arduino Uno R3 was released, all the documentation for their very popular Inventor’s Kit was obsoleted overnight. In response to these supply chain problems, Sparkfun created the RedBoard.

Sparkfun has always offered to pay royalties on the RedBoard to Arduino LLC, just as they do with the Arduino Pro and Pro Mini. Effectively, Sparkfun is on the fence, with offers to manufacture the Arduino Zero, Uno, Mega, and Due coming from the LLC.

The reason for this is consumers. If someone wants an Arduino SRL-manufactured board, they’ll buy it. If, however, a customer wants to support Arduino LLC, that option is on the table as well.

It’s not a pretty position to be in, but it does show how someone can support one Arduino over another. In a year or two, there will only be one Arduino, but until then, if you have a preference, at least Sparkfun is giving you a choice.

Credit to Sparkfun for the great Spy vs. Spy image. Why don’t you sell googly eyes?

An Improved Table Saw Fence With Threaded Rod

April 15, 2015 by Brian Benchoff 68 Comments

Back in the bad old days, table saw fences were terrible. You would have to measure the top and bottom of the fence before each cut, just to make sure the fence was square to the blade. In the 1970s, [Bill Biesemeyer] invented a better table saw fence, one that was always square, and included a measuring tape, right on the table saw.

[Jer] wanted an upgrade for his table saw and came up with what might be the next evolution of the table saw fence. It will always produce a square cut, but unlike the 1970s version, this fence has repeatability. If you rip a board to 1″, move the fence, come back to it after a month, and try to rip another board to 1″, those two boards will be exactly the same width.

The secret to this repeatability is a threaded rod. On the front of the fence is a big, beefy piece of threaded rod with 16 threads per inch. On the fence itself is two nuts, cut in half, welded to the guide, with a lever and cam to lock them in place.

When the lever is up and the nuts are disengaged from the threaded rod, the fence easily moves from one side of the table to the other. When the fence is locked down, it locks to the nearest 16th of an inch, and only the nearest 16th of an inch. While that may seem a little large for a relatively expensive tool, this is wood we’re talking about here. There’s not much reason to make the resolution of this fence any smaller; wait until the humidity changes and you’ll have a piece of wood that’s the desired dimension.

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