Turn a PC on with a Knock and an ATTiny

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Pressing the power button on your computer usually isn’t too much trouble, unless your computer is stored away somewhere hard to reach. [Joonas] has been hard at work on a solution that would also impress his friends, building a knock sensor to turn on his PC.

For around $10 in parts he put together an ATTiny45 that emulates a PS/2 device, which takes advantage of his computer’s ability to boot upon receiving PS/2 input. The build uses a Piezo buzzer and a 1M Ohm resistor as a knock sensor exactly as the official Arduino tutorial demonstrates, and one of those PS/2-to-USB adapters that are most likely lurking in the back corner of every drawer in your office.

[Joonas] used AVRweb to disable the 8X clock divider so there’d be enough clock cycles for PS/2 communication, then loaded some test code to make sure the vibrations were being detected correctly. You can check out his Github for the final code here, and stick around after the break for a quick video demo. Then check out a similar hack with [Mathieu's] home automation knock sensor.


Slap Hackaday Logo on Something and Win a Trinket

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It’s no secret that we love to see project demos that pander to Hackaday. This often comes in the form of our page loaded on the screen in build photos, or creative use of our skull and wrenches logo. Now’s your chance to pander for a smidge of loot. [Phillip Torrone] offered up 20 of Adafruit’s new 5v Trinket boards as giveaways, and we can’t say no to getting free stuff in the hands of the readers.

So here’s the deal: Use the Hackaday logo on something. This can be just about anything. The images above show three examples made by Hackaday staff. There’s the logo built brick-by-brick on a Minecraft Survival server, a 3D version printed as a badge, and a somewhat squished version inside of a QR code. We will (seemingly arbitrarily) pick twenty winners from all of the submissions, but here’s a few guidelines to help you rise above:

Send your submission details to our tips line (don’t forget to say something like [Trinket Contest] in the title!). In order to receive a prize you must include your name, address, and email address (these will only be used by Adafruit to deliver the hardware and notify you when it has shipped). Get your entry in by Friday, November 1st in order to qualify. Obviously Hackaday, SupplyFrame, and Adafruit employees and their families aren’t eligible to win.

Adventures in Hackerspacing: Freeside Atlanta, Part II

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AppId is over the quota


This week on Adventures in Hackerspacing, Freeside Atlanta Part II: Hacking the Hackerspace!

After learning about the culture behind the space, I was eager to ask hackerspace veterans [Alan] and [Steven] about nuts and bolts, about behind-the-scenes crucial decisions, and one question in particular: What’s the most important requirement for a hackerspace? [Alan] jumped in with this response:

Number one by and far is a willing landlord. I think if you have a willing landlord everything else is incidental. You make it hard on yourself if you are on the second story, but take the second story if you have a willing landlord.

That wasn’t the answer I was expecting, but when you look around Freeside, it starts to make sense…


Graffiti, street art, or some kind of mural covers nearly every wall, including a bowel-evacuatingly frightening Slenderman who lurks behind the bathroom door. I expected “size of the facility” to rank higher on their list—and at nearly 6,000 square feet, Freeside has heaps of leg room—but even a garage or a small office can function as a hackerspace for a handful of folks doing software or small electronics work.

Instead, [Alan] and [Steven] cast their vote for a place you can modify and improve. Freeside is located among the warehouses of the Metropolitan Business and Art District, which has a history of housing those who make creative use of the spaces. According to [Alan], Freeside is a conservative user of the property as compared to others in the same warehouse community. It’s also on the ground floor, because lugging heavy equipment up stairs is more trouble than it’s worth. There are exceptions. MASScollective, as [Alan] pointed out, is a three-story space with a freight elevator, so a space off the ground floor isn’t necessarily a deal-breaker. You just need to be creative about getting equipment above the ground floor.

[Alan] and [Steven] also took time to detail some of the legal issues that a hackerspace and its administrators may face. But first, the typical disclaimer:

I am not a lawyer, and the following information is not legal advice. [Alan] and [Steven] aren’t lawyers either, so be sure to consult an actual attorney before making any legal decisions about your hackerspace.

Freeside is officially a Georgia Non-Profit corporation, and they’ve applied for federal 501(c)(3) status, which comes with some tax breaks. Filing as a federal non-profit is quite the undertaking. [Alan] explained that the mountain of paperwork (around 80 pages) and increased responsibility for consistent and accurate record keeping can deter a space from applying. For Freeside, it’s worth the effort. Federal non-profit status looks good on grant applications, and [Steven] admits that they’ve been turned down for a few microgrants because Freeside’s still waiting to hear back on the 501(c)(3); their application is stuck in the backlog.

It’s also important to pick the correct type of organization for your space. Freeside chose 501(c)(3)—an educational and/or scientific organization—because they make an effort to educate the community and their members have published scholarly articles in the medical field. Some spaces go the route of the 501(c)(7)—social and recreational—because they can only claim to be a workshop organization.

They also pointed out the benefits of registering as a Limited Liability; if there’s a debt incurred by the organization, it’s founders are not liable for that debt. They can dissolve the corporation: assuming the organization has otherwise behaved responsibly. As [Steven] puts it, negligence trumps most legal safety nets, so it’s best to be above board on your paperwork and practices.

Then there’s the other kind of liability concern: safety.


Freeside has one hell of a workshop, and [Alan] was happy to give me a tour, but not before I strapped on the safety goggles that he handed me. No one expects members to walk in with an encyclopedic knowledge of how to operate every power tool. Whoever teaches you to use the big, loud equipment, however, is potentially liable for misuse by the trainee. If [Alan] taught you how to operate the table saw and you got hurt, whose fault is it? This was a problem that had Freeside members on edge. [Alan] explained how they approached the issue by carefully choosing the language that surrounds instruction, then securing a legal solution:

We don’t say ‘we certify’ you to use anything. There’s a welder guy we know who is able to actually certify people to weld, but if we’re doing a build-out of the space where we’re cutting 2×4's, I’m going to assume that they’ll use the chop saw. If they use the table saw and hurt themselves, that’s where things get tricky. They volunteered, so they can’t hold Freeside responsible, but that doesn’t include me personally. So I took out an umbrella policy to protect me from things like that.

The personal umbrella insurance is less expensive than directors and officers insurance—which [Alan] only recommends if you plan to hire staff members (it covers equal opportunity, etc.) Now, as long as the Freeside guys aren’t creating a negligent environment, instruction is no longer a problem. You can check out Freeside’s policy page for more information and other guidelines. Many of these policies should be read as an “operations manual” rather than a strict rule book. Like most things at Freeside, their policies are empowered by fluidity.


Freeside has more stories to tell, but I’ll end the adventure here and instead suggest that you check out their space yourself. Swing by on Tuesday evenings for their open house, where you’re sure to meet plenty of friendly, knowledgeable folks, and can enjoy [Alan's] bizarre taste in YouTube videos on the big screen.

A monumental thank you to both [Alan Fay] and [Steven Sutton] for tolerating over three hours of my questions and at least as many hours of lurking, and a much overdue thanks to my old friend [Brian Cribbs] for introducing me to the Freeside community.

Finally, I want to hear about your adventures. Drop me a line and tell me about your space’s politics, crazy mishaps, how you regulate safety, legal threats, the creepy guy who sat in his car outside your space while calling to ask if he can use it to put on a puppet show for children (You’ll have to ask [Steven] about that one), or anything you’d like to see in the next installment of Adventures in Hackerspacing.

USB Implementers Forum Says No to Open Source

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For the longest time. one of the major barriers to hobbyists and very small companies selling hardware with a USB port is the USB Implementers Forum. Each USB device sold requires a vendor ID (VID) and a product ID (PID) to be certified as USB compliant. Adafruit, Sparkfun, and the other big guys in the hobbyist market have all paid the USB Implementers Forum for a USB VID, but that doesn’t help the guy in his garage hoping to sell a few hundred homebrew USB devices.

Arachnid Labs had an interesting idea to solve this problem. Since other USB device vendors such as Microchip and FTDI give away USB PIDs for free, a not for profit foundation could buy a VID, give PIDs away to foundation members making open source hardware, and we would all live in a magical world of homebrew devices that are certified as USB compliant.

This idea did not sit well with VTM Group, the people serving as the management, PR, legal, and membership and licensing department of the USB Implementers Forum. In a slightly disproportionate response, the VTM Group told Arachnid Labs to,

Please immediately cease and desist raising funds to purchase a unique USB VID for the purpose of transferring, reselling or sublicensing PIDs and delete all references to the USB-IF, VIDs and PIDs for transfer, resale or sublicense from your website and other marketing materials.

Interestingly, Arachnid Labs’ and scores of other requests for an open source USB VID haven’t hit the desk of anyone at the USB Implementers Forum, the people who are actually in charge of designating USB VIDs and PIDs. There are a number of ideas to get around VTM Group that include squatting on USB VID 0xF055, but we’re at a loss why there couldn’t be a foundation that gives out open source USB PIDs. Microchip, FTDI, and Openmoko do the same, so perhaps it’s time to email some key people at HP, Intel, and Microsoft

The Most Minimal Homebrew Computer

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Perfection is achieved not when there is nothing more to add, but when there is nothing left to fail. Going by that metric, [Stian]‘s three-chip 6502 homebrew computer is the epitome of perfection. It’s a real, working, homebrew retrocomputer using only three chips: a CPU, some RAM, and a microcontroller to bootstrap the computer and provide a video output,

The key to this minimalist build is having the entire boot process controlled by an ATMega16 microcontroller, This interfaces to the 6502 through a dual-port SRAM, a 1 kilobyte Cypress CY7C130. This dual-port RAM allows the CPU and microcontroller to access the same bit of memory, making it easy to bootstrap a computer from a bit of AVR code.

Output is provided with [Stian]‘s ATMega video text generator putting a 37×17 characters on any television with an RCA jack. While input isn’t handled yet, [Stian] says it should be possible with his AVR PS/2 keyboard library.

While other 6502 homebrew computers such as [Quinn Dunki] Veronica can reach unparalleled heights of complexity, there is a lot to be said about the minimalism of [Stian]‘s three-chip computer. With some clever coding and a modified parts list, it may well be possible to put a retrocomputer in the hands of everyone with a bare minimum of cost and parts.

CAN Hacking: Introductions

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There is a right way and a wrong way to design embedded systems.

The wrong way centralizes functionality that has no business being together, and makes it opaque to repairmen. This is usually chosen so as to “optimize for cost” by minimizing the number of computers… you know, in a “there’s maybe a market for 5 computers globally” kind of way.

The right way is to keep things as simple as will work, preferably not even using OS’s, when the tasks can be separated so one function per microcontroller. This way there is no multiplication of complication, and each separate processor’s code becomes simple and easily maintained. (and preferably also, kept with the install so that future repairmen have a chance to fix it!). This is known as robust design, engineering for maximum reliability, as a priority far above “cost”.

As manufacturers get better at this, expect, nay, demand that they become compliant! An essential, and yet still lacking part of this is the availability of the source, as well as the barrier-to-modification. The auto industry is notorious for keeping all their tech secret – so much so that most “scientifically published, peer reviewed” papers read more like sales brochures with even less actual detail than the patents that they’re trying to push.

Unfortunately, it seems keeping source code secret has a reputation as being some kind of “good” engineering practice, even though it’s basically fundamentally at odds with science and engineering. If you contract an engineer to make something for you, you will get the blueprints – if they don’t provide them, then they didn’t engineer it.

Car manufacturers have a lot to learn in this regard, but even more so do the “engineering software” companies who “sell products” in the MSFT style. It’s disgusting, and one day people will find it difficult to believe that it was ever considered reasonable business practice.

All that said: CAN is very good – no where near the performance of, say, FireWire, but still exactly as “KISS” like as you could hope for in a low speed / high reliability / easily debugged multidrop communications protocol. (Firewire is perfection at high bandwidth, but carries with it quite an overhead in terms of protocol, it was clearly designed by a comittee of computer engineers obessed with getting every little detail right. It is anarchistic democracy to USB’s benevolent dictatorship. CAN is just a few mechanics talking shop, and getting shit done whilst occasionally yelling over the other, but that’s ok, because everyone knows the pecking order, and shuts up and listens when it’s urgent.)

Apart from sheer BW, CAN shits all over ethernet’s stupid “if a collision, wait a random time, then try again” approach to sharing a wire. (Hint: this is why ethernet is not used to share wires anymore – do you know the difference between a “hub” and a “switch”? Remember 10Base2 ?)

Apart from the horribleness putting a “standard” behind a paywall (just like selling software licences imho, anti education.), CAN is a good bit of work, whose actual impact on the world for the better will be proportional to those benefiting from it, and therefore dependant upon being widely understood and used where appropriate. (Again, something that paywalls / licensing / general IP shit destroys).

I’m looking forward to this series :)

Introducing the Shapeoko 2

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For all the 3D printers that hit the Hackaday tip line, it’s surprising we don’t see more CNC routers. They’re arguably more useful tools, and with the ability to mill wood, plastic, and non-ferrous metals, open up the door to a whole bunch more potential builds. One of the most popular – and certainly one of the least expensive – CNC routers out there, the Shapeoko, just received a huge update that makes this minimal machine even more capable.

The new Shapeoko 2 keeps the same V wheel on an aluminium extrusion design with Makerslide, but fixes a few problems that limited the original Shapeoko. There’s a larger work area on this version, and the Y axes feature dual stepper motors. The biggest feature, we think, is the ability to handle materials larger than the machine itself thanks to its open front and back.

The Shapeoko 2 is available in two versions, a $300 mechanical kit that requires you to go out and get some motors, a power supply, and a grblShield, the full version, for $650, includes everything you’ll need to start routing wood metal and plastic at home.