Tag Archives: DIY

Arduino Watchdog Has Bite And Doesn’t Need Treats

My dog Jasper isn’t much of a watchdog: he’s too interested in sleeping and chasing my cats to keep an eye on things. Fortunately, [Vadim] has come up with a more reliable alternative with this simple Arduino watchdog. It’s designed to work with crypto coin mining rigs, but it could be easily adapted for other high-uptime uses, such as file servers or doomsday weapons.

The way it works is simple: a small program on the watched computer sends a command over the serial port: a polite “hello”. The Arduino watchdog picks this up and responds with an equally polite “HELLO”. That starts the watchdog running. A simple Java program on the watched computer then sends a ping every five seconds over the serial port to let the watchdog know it is still running okay.

If the watchdog doesn’t receive this ping, it uses reed relay wired into the reset pins of the computer to trigger a reset. It then waits for the watched computer to say hello, starting the process again.

[Vadim] includes a demo video where the system resets an unreliable crypto mining rig. It does have limitations, of course: if the mining program crashes without taking down the entire computer, the watchdog won’t be triggered, and it won’t work if the problem requires a full hard power reset rather than a soft reset. dIt’s a neat little build that could be easily modified to handle all these issues, though, and you don’t need to keep feeding it treats to keep its attention, unlike Jasper.

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Rapidly Prototyping Prosthetics, Braille, and Wheelchairs

We live in an amazing time where the availability of rapid prototyping tools and expertise to use them has expanded faster than at any other time in human history. We now have an amazing ability to quickly bring together creative solutions — perfect examples of this are the designs for specialized arm prosthetics, Braille printing, and custom wheelchair builds that came together last week.

Earlier this month we published details about the S.T.E.A.M. Fabrikarium program taking place at Maker’s Asylum in Mumbai. The five-day event was designed to match up groups of makers with mentors to build assistive devices which help improve the condition of differently-abled people.

The participants were split into eight teams and they came up with some amazing results at the end of the five-day program.

Hands-On: Prosthetic Designs That Go Beyond

Three teams worked on projects based on Bionico – a myoelectric prosthesis

DIY Prosthetic Socket – a Human Machine Interface : [Mahendra Pitav aka Mahen] lost his left arm during the series of train bomb blasts in Mumbai in 2006, which killed 200 and injured over 700 commuters. He uses a prosthetic arm which is essentially a three-pronged claw that is cable activated using his other good arm. While it is useful, the limited functionality restricted him from doing many simple things. The DIY Prosthetic socket team worked with [Mahen] and [Nico Huchet] from MyHumanKit (who lost his right arm in an accident 16 years back), and fabricated a prosthetic forearm for [Mahen] with a modular, 3D printed accessory socket. Embedded within the arm is a rechargeable power source that provides 5V USB output at the socket end to power the devices that are plugged in. It also provides a second port to help recharge mobile phones. Also embedded in the arm was an IR reflective sensor that can be used to sense muscle movements and help trigger specific functions of add-on circuits, for example servos.

Hackberry Feedback System – assembly of the Hackberry Hand and improvisation of the feedback system : The prosthetic forearm with socket needs attachments to make it useful. The Hackberry Feedback System project built a pair of articulated hands with sensors for feedback. This team assembled two Exiii Hackberry right and left hand kits, which by itself is a pretty complicated process. An embedded Arduino drives several servos for the thumb and fingers. To extend functionality, team mentor [Jean Noel] helped add a temperature sensor which is embedded in the palm and hooked up to the Arduino, that drives a bunch of WS2812 smart RGB LEDs mounted as a bracelet on the wrist of the arm. In “Temperature” measurement mode, it indicates blue for cold and red for hot objects. In the “Fun” party mode, is does random animations. On the second assembly, they embedded a pair of force-sensing resistors connected to the Arduino on that hand. The Arduino drives a servo motor whose horn was used to provide tactile feedback.

SHIVA HANDS – Creating Funny/Tools Hands : Often, a specific accessory provides better functionality for the user compared to an articulated hand. The SHIVA hands team designed and built several add-on attachments that could fit on the DIY Prosthetic Arm. [Mahen] suggested a Mobile phone holder with a built-in laser pointer and a mosquito swatter holder (useful in tropical Mumbai), while [Nico] wanted a plectrum holder since he loves playing the guitar. They also planned to build a Nerf Gun holder attachment sometime in the future.

Words with Feeling: Making Braille

Three teams worked on braille devices based on the Braille rap – using a 3D printer as a braille embosser.

BrailleRap STEAM – A vision to create a Braille map for Visually Impaired people : For a visually impaired person who visits a public space such as a library, a restaurant or a train station, navigation is a big constraint. The goal of this team, mentored by [Hugues Aubin], was to investigate various ways in which public “braille” maps can be created and how additional information can be displayed at vital way points within the space, whose location is identified on the braille map. The team tried various fabrication methods using the tools and facilities available at the makerspace. Another idea they tried, after interacting with the visually impaired team members, was to use material of different textures to identify specific areas on a map. Abrasive textures (emery/sandpaper) in various grits were found to be quite useful, and they plan to investigate further the use of textures to embed information within the maps. Team member [Arthur] took a Makerbot Replicator 3D printer and modified its firmware to convert it into a Braille embossing machine. The only mechanical modification needed is a simple metal pin embedded in a 3D printed adapter that is snap fitted over the hot end. Using this, they were successful in using the 3D printer to emboss braille on thick paper and plastic film.

BrailleRap STEAM CNC – Modifications to the CNC for replicating BrailleRap : This team took possession of the ShapeOko CNC mill lying at the Maker’s Asylum and proceeded to add the electronics and code to it for use as a braille embosser. This is a fairly inexpensive and quick way to build a braille embosser using materials commonly available at a makerspace. Besides the mechanics of the CNC mill, all that’s needed is an Arduino, a motor driver shield and a power supply. [Arthur] wrote some great code which takes text input and converts it to Braille and then generates the required G-code that can be sent to the CNC for embossing. The CNC team was successful in embossing braille on paper, plastic as well as on thin metal obtained from discarded soda cans.

OpenBraille Steam – building a low cost braille printer : The OpenBraille team worked on building a braille printer from scratch using a kit of parts which the MyHumanKit team had got with them. The open source kit consisted of commonly available parts used for building 3D printers and a few custom, 3D printed pieces. The original project is still work in progress and a bit rough around the edges. Besides, the build team did not have much prior experience, so building this machine was a bit of a struggle for them but a great learning experience. Towards the end, they did manage to make a few sample prints, and we hope to see further progress on this over time.

Roll with It: Wheelchairs Where They Weren’t Before

The last two projects looked at how wheelchair bound people could be helped using assistive tech.

O-trotti – universal, cost-effective attachment to convert normal wheelchair to electric : In large parts of the world, the differently-abled do not have state support for subsidised assistive tech such as wheelchairs. Most people who need them can barely afford the low-cost, manual versions. Electric wheelchairs, consequently, are out of reach for most people. An easy workaround would be to build an add-on device that can convert a regular wheelchair to an electric one. Unfortunately, even these conversion kits are quite expensive.

The O-trotti team’s brief was to come up with a modular design for an electric wheel which could be snapped on to normal wheelchairs. The team, mentored by [Yohann Modulaire], worked on two projects simultaneously. One was to take a commercially available electric trike and use its components — inspired by the e-Trotti design. The other team worked on building a device from scratch. In both cases, the hardware required is pretty basic. A geared DC motor, sealed lead acid battery, and a controller for speed and direction control. Both versions were built within the five days, but this is a project that still needs work to get to a finished product.

Fl’Air – build a wheelchair that can be used for paragliding : This was, by far, the most ambitious project and the one that needed the most safety considerations. Paragliding is not something that the differently abled “need”, but it is certainly something that must be made more accessible for them to be able to enjoy the thrill of flying. Wheelchair paragliding is a tandem activity, so the pilot needs to be extremely skilled and licensed. [John Lejeune], the team mentor, is an expert paraglider himself, so he knew exactly what was required, especially in terms of safety. Also part of this team was [Avi Malik], an ex-Indian Air Force pilot and international paragliding expert who doesn’t let his artificial foot get in the way of his passion for flying. The team working on this had a couple of automotive and bike building enthusiasts and by the end of day 5, they had successfully managed to design the wheelchair, get all the required pipes cut and bent, and received a whole lot of minor parts cut in sheet metal from a local water-jet cutting facility. This build is still work in progress, but we look forward to seeing how it progresses and eventually see a test flight involving [John], [Avi] and the other experts at TemplePilots in Kamshet, near Mumbai.

It is not easy to concisely report on a five-day program involving almost 100 hackers working on multiple projects so we had to skip a lot of details. This was an amazing experience and that story is shared through each of the project pages. Take some time to further explore the projects that interest you, and please leave your feedback and encouragement for the teams on their project pages on Hackaday.io.

About Fabrikarium:

The S.T.E.A.M Fabrikarium was unlike most other “hackathons”. To start with, the 65 participants and 20 mentors included 15 differently abled people who not only provided their feedback, but were also an integral part of the various teams and took part in the design and building of the assistive devices. The MyHumanKit group had built five open source projects during an earlier Fabrikarium in France. The goal for this event was to build on these existing projects and replicate as well as improve them.

The event was hosted at Maker’s Asylum in Mumbai. [Bodo Hoenen] from New York, [Delphine] from the MyHumanKit group in Rennes, France and [Anool Mahidharia] from Mumbai were present on hand to help out with the documentation. Hackaday was proud to team up to provide documentation support via Hackaday.io to ensure that the teams could record their Open Source work and share it with the rest of the community.

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“The Commodore Story” Documentary Premieres Today

What is it about a computer that was introduced 36 years ago by a company that would be defunct 12 years later that engenders such passion that people still collect it to this day? We’re talking about the Commodore 64, of course, the iconic 8-bit wonder that along with the other offerings from Commodore International served as the first real computer to millions of us.

There’s more to the passion that Commodore aficionados exhibit than just plain nostalgia, though, and a new documentary film, The Commodore Story, seeks to explore both the meteoric rise and fall of Commodore International. Judging from the official trailer below, this is a film anyone with the slightest interest in Commodore is not going to want to miss.

It will of course dive into the story of how the C-64 came to be the best selling computer in history. But Commodore was far from a one-trick pony. The film traces the history of all the Commodore machines, from the PET computers right through to the Amiga. There are interviews with the key players, too, including our own Bil Herd. Bil was a hardware engineer at Commodore, designing several machines while there. He has shared some of these stories here on Hackaday, including the development of the C128  (success to the C64) and making the C364 speak.

We can’t wait to watch this new documentary and luckily we won’t have to. It’s set to start streaming on Netflix, Amazon, and iTunes today, so pop up some popcorn and settle in for a two-hour ride through computer history. However, those of you in the Mountain View area have an even better opportunity this evening.

The Commodore Story will be premiered live at 6:30pm PST at the Computer History Museum. Grab your tickets to the premiere and a Q&A session with Bil Herd, Leonard Tramiel, and Hedley Davis.

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Tiny OLED and 2/4 Port USB Hub for PocketBeagle


PocketBeagles, unless you’re referring to the adorable hound they are apparently named after, are single-board computers the size of a key fob, featuring half a gig of RAM and a one gigahertz processor. While we sometimes look past just how amazing systems like this are, if you grew up in the 1980s and 90s, you probably remember power like this at one point being mind-blowing in a full-sized computer.

Nonetheless, boards like this and their kind are now quite common, and hacker Microwavemont has come up with an addition that makes the PocketBeagle even more exciting—an extension board that adds 2 or 4 USB ports, as well as a fingernail-sized 64×32 pixel OLED display controlled via an I2C interface. The device plugs in on top of the base board as a “cape” and allows you to plug in all manner of accessories into it, and view what’s going on via its shockingly small display. Be sure to check out how great the display looks in the video below:

If you like this idea, but don’t need an OLED display, he does offer a version without it. On the other hand, the price difference between the two models is only $4, so adding a little screen would be tough to pass up!

The post Tiny OLED and 2/4 Port USB Hub for PocketBeagle appeared first on Tindie Blog.

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DIY Cryogel Sustains Live Cells

We like to think our readers are on the cutting edge. With the advent of CRISPR kits at home and DIY bio blooming in workshops across the world, we wanted to share a video which may be ahead of its time. [The Thought Emporium] has just shown us a way to store eukaryotic cells at room temperature. His technique is based on a paper published in Nature which he links to from the YouTube page, but you can see his video after the break.

Eukaryotic cells, the kind we are made of, have been transported at low temperatures with techniques like active refrigeration, liquid nitrogen, and dry ice but those come with a host of problems like cost, convenience, and portability. Storing the cells with cryogel has been shown to reliably keep the cells stable for up to a week at a time and [The Thought Emporium] made some in his homemade freeze-dryer which he’s shown us before. The result looks like a potato chip, but is probably less nutrious than astronaut ice cream.

If cell transport doesn’t tickle your fancy, cryogel is fascinating by itself as a durable, lightweight insulator similar to Aerogel. You can make Aerogel at home too.

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Next Week: Bring-A-Hack In NYC

Hackaday, along with Ultimaker and New Lab, are hosting an extravaganza of super hacks and more in New York next week. Grab a project you’re working on and join us on Wednesday, February 28 in Brooklyn.

This is all about showcasing the coolest, newest stuff being worked on by makers, hackers, artists, and engineers. Get ready to talk hardware, stare into far too many LEDs, and enjoy drinks and camaraderie. The event is being hosted by New Lab, and we’re teaming up with Ultimaker to bring you a night of fun and solder fumes. We have great speakers lined up, and we’ve blocked out some time for lightning talks too so fill out this form if you’re interested.

Support for the KiCad Project

RSVPs for this meetup are $5, with all proceeds being donated to the KiCad project via CERN.

Sending some funding to support this Open Source EDA project is a great thing. If this fee is a no-go for you, we’re also looking for a few volunteers for the event. If you’d like to help out and skip that $5 cover, send us a note on Hackaday.io.

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A Robot For Everything: Now Even Zippers

Sometimes we see projects that are so clever while being remarkably simple, that we can’t help thinking: Why didn’t I think of that! Take [Haresh Karnan]’s zipper robot, for example. It’s a well-designed 3D-printed shell with two geared motors for traction, that can both undo and do up zippers. Behind that seemingly simple design probably lies a huge iterative design process to arrive at a shape perfect for the job, but the end result is so elegant that even [Haresh]’s write-up and Hackaday.io page for the project are short and to the point. Download the STL file, snap in the motors, apply to a zipper, and away you go. He suggests rubber bands as a traction aid, but that’s pretty much it.

The results can be seen in the video below the break. While we might be tempted to make jokes about the terminally lazy using this device to save unnecessary labour after a toilet break, we can see that it might have a real application. If you have any friends with restricted dexterity you will understand how having an automated helper with such a fiddly task as a zipper could be an extremely useful accessibility aid.

While we’re on the subject of zippers, if you missed it a few weeks ago here’s our in-depth look at their story.

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