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.

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Vintage Sewing Machine To Computerized Embroidery Machine

It is February of 2018. Do you remember what you were doing in December of 2012? If you’re [juppiter], you were starting your CNC Embroidery Machine which would not be completed for more than half of a decade. Results speak for themselves, but this may be the last time we see a first-generation Raspberry Pi without calling it retro.

The heart of the build is a vintage Borletti sewing machine, and if you like machinery porn, you’re going to enjoy the video after the break. The brains of the machine are an Arduino UNO filled with GRBL goodness and the Pi which is running CherryPy. For muscles, there are three Postep25 stepper drivers and corresponding NEMA 17 stepper motors.

The first two axes are for an X-Y table responsible for moving the fabric through the machine. The third axis is the flywheel. The rigidity of the fabric frame comes from its brass construction which may have been soldered at the kitchen table and supervised by a big orange cat. A rigid frame is the first ingredient in reliable results, but belt tension can’t be understated. His belt tensioning trick may not be new to you, but it was new to some of us. Italian translation may be necessary.

The skills brought together for this build were vast. There was structural soldering, part machining, a microcontroller, and motion control. The first time we heard from [juppiter] was December 2012, and it was the result of a Portable CNC Mill which likely had some influence on this creation. Between then, he also shared his quarter-gobbling arcade cabinet with us.

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Debunking Moon Landing Denial With An Arduino And Science

It’s sad that nearly half a century after the achievements of the Apollo program we’re still arguing with a certain subset of people who insist it never happened. Poring through the historical record looking for evidence that proves the missions couldn’t possibly have occurred has become a sad little cottage industry, and debunking the deniers is a distasteful but necessary ongoing effort.

One particularly desperate denier theory holds that fully spacesuited astronauts could never have exited the tiny hatch of the Lunar Excursion Module (LEM). [AstronomyLive] fought back at this tendentious claim in a clever way — with a DIY LIDAR scanner to measure Apollo artifacts in museums. The hardware is straightforward, with a Garmin LIDAR-Lite V3 scanner mounted on a couple of servos to make a quick pan-tilt head. The rig has a decidedly compliant look to it, with the sensor flopping around a bit as the servos move. But for the purpose, it seems perfectly fine.

[AstronomyLive] took the scanner to two separate museum exhibits, one to scan a LEM hatch and one to scan the suit Gene Cernan, the last man to stand on the Moon so far, wore while training for Apollo 17. With the LEM flying from the rafters, the scanner was somewhat stretching its abilities, so the point clouds he captured were a little on the low-res side. But in the end, a virtual Cernan was able to transition through the virtual LEM hatch, as expected.

Sadly, such evidence will only ever be convincing to those who need no convincing; the willfully ignorant will always find ways to justify their position. So let’s just celebrate the achievements of Apollo.

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Handheld GPS Tracks All The Things

With a GPS on every smartphone, one would be forgiven for forgetting that handheld GPS units still exist. Seeking to keep accurate data on a few upcoming trips, [_Traveler] took on a custom-build that resulted in this GPS data logger.

Keeping tabs on [_Traveler] is a Ublox M8N GPS which is on full-time, logging data every 30 seconds, for up  to 2.5 days. All data is saved to an SD card, with an ESP32 to act as a brain and make downloading the info more accessible via WiFi . While tracking the obvious — like position, speed, and time — this data logger also displays temperature, elevation, dawn and dusk, on an ePaper screen which is a great choice for conserving battery.

The prototyping process is neat on this one. The first complete build used point-to-point soldering on a protoboard to link several breakout modules together. After that, a PCB design embraces the same modules, with a footprint for the ESP’s castellated edges and header footprints for USB charing board, SD card board, ePaper, etc. All of this finds a hope in a 3D printed enclosure. After a fair chunk of time coding in the Arduino IDE the logger is ready for [_Traveler]’s next excursion!

As far as power consumption in the field, [_Traveler] says the GPS takes a few moments to get a proper location — with the ESP chewing through battery life all the while — and plans to tinker with it in shorter order.

Not all GPS trackers are created equal: sometimes all you need is a stripped-down tracker for your jog, or to know exactly where every pothole is along your route.

[Via /r/electronics]

Car as a computer mouse

Turning A Car Into A Computer Mouse

[William Osman] and [Simone Giertz] have graced our pages before, both with weird, wacky and wonderful hacks so it’s no surprise that when they got together they did so to turn Simone’s car into a computer mouse. It’s trickier than you might think.

They started by replacing the lens of an optical mouse with a lens normally used for a security camera. Surprisingly, when mounted to the car’s front bumper it worked! But it wasn’t ideal. The problem lies in that to move a mouse cursor sideways you have to move the mouse sideways. However, cars don’t move sideways, they turn by going in an arc. Move your mouse in an arc right now without giving it any sideways motion and see what happens. The mouse cursor on the screen moves vertically up or down the screen, but not left or right. So how to tell if the car is turning? For that, they added a magnetometer. The mouse then gives the distance the car moved and the magnetometer gives the heading, or angle. With some simple trigonometry, they calculate the car’s coordinates.

The mouse click is done using the car’s horn, but details are vague there.

And yes, using the carmouse is as fun as it sounds, though we still don’t recommend texting while driving using this technique. Watch them in the videos below as they write an email and drive a self-portrait of the car.

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Underwater Logging For Science

Logging data with an Arduino is old-hat for most Hackaday readers. However, [Patricia Beddows] and [Edward Mallon] had some pretty daunting requirements. Their sensors were going underground and underwater as part of an effort to study conditions underwater and in caves. They needed to be accessible, yet rugged. They didn’t want to use batteries that would be difficult to take on airplanes, but also wanted more than a year of run time. You can buy all that, of course, if you are willing to pay the price.

Instead, they used off-the-shelf Arduino boards connected together inside PVC housings. Three alkaline AA batteries are compact and give them more than a year of run time. They wrote a journal paper to help other scientists use the same techniques for the Sensors journal published by the Multidisciplinary Digital Publishing Institute.

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Arduino Keyboard Is Gorgeous Inside And Out

While the vast majority of us are content to plod along with the squishy chiclet keyboards on our laptops, or the cheapest USB membrane keyboard we could find on Amazon, there’s a special breed out there who demand something more. To them, nothing beats a good old-fashioned mechanical keyboard, where each key-press sounds like a footfall of Zeus himself. They are truly the “Chad” of the input device world.

But what if even the most high end of mechanical keyboards doesn’t quench your thirst for spring-loaded perfection? In that case, the only thing left to do is design and build your own. [Matthew Cordier] recently unveiled the custom mechanical keyboard he’s been working on, and to say it’s an elegant piece of engineering is something of an understatement. It may even look better inside than it does on the outside.

The keyboard, which he is calling z.48, is based around the Arduino Pro Micro running a firmware generated on kbfirmware.com, and features some absolutely fantastic hand-wiring. No PCBs here, just a rainbow assortment of wire and the patience of a Buddhist monk. The particularly attentive reader may notice that [Matthew] used his soldering iron to melt away the insulation on his wires where they meet up with the keys, giving the final wiring job a very clean look.

Speaking of the keys, they are Gateron switches with DSA Hana caps. If none of those words mean anything to you, don’t worry. We’re through the Looking Glass and into the world of the keyboard aficionado now.

Finally, the case itself is printed on a CR-10 with a 0.3 mm nozzle and 0.2 mm layers giving it a very fine finish. At 70% infill, we imagine it’s got a good deal of heft as well. [Matthew] mentions that a production case and a PCB are in the cards for the future as he hopes to do a small commercial run of these boards. In the meantime we can all bask in the glory of what passes for a prototype in his world.

We’ve seen some exceptionally impressive mechanical keyboards over the years, including the occasional oddity like the fully 3D printed one and even one that inexplicably moves around. But this build by [Matthew] has to be one of the most elegant we’ve ever come across.