Quit Hunching Over Your Screen With A Little Robotic Help

October 20, 2021 by Dave Rowntree 8 Comments

[Norbert Zare] has identified a problem many of us suffer from – chronically bad posture. Its very common to see computer users hunched forwards over a screen, which eventually will lead to back problems. He mentions that most posture correction devices are pretty boring, so the obvious solution to [Norbert] was to build a simple robot to give you a friendly nudge into the correct position.

This simple Arduino-based build uses the ubiquitous MPU-6050 which provides 3-axis acceleration and 3-axis gyro data all processed on-chip, so it can measure where you’re going, which way you are orientated and how fast you are rotating. This is communicated via the I²C bus, so hooking into an Arduino or Raspberry Pi is a simple affair. There are plenty of Open Source libraries to work with this very common device, which helps reduce the learning curve for those unfamiliar with programming a fairly complex device.

At the moment, he is mounting the sensor on his body, and hard-wiring it, so there’s already some scope for improvement there. The operating premise is simple, if the body angle is more than 55 degrees off vertical, move the servos and shove the body back in to the correct position.

The project GitHub has the code needed, and the project page over on Hackaday.io shows the wiring diagram.

We have seen quite a few projects on this subject over the years, like this one that sends you mobile notifications, an ultrasonic rangefinder-based device, and one that even uses a webcam to keep an eye on you. This one has the silliness-factor, and we like that round these parts. Keep an eye on [Norbert] we’re sure there more good stuff to come!

Continue reading “Quit Hunching Over Your Screen With A Little Robotic Help” →

Building A Hammer Powered By Gunpowder

October 20, 2021 by Lewin Day 24 Comments

Hammers are pretty straightforward tools. If you need more impact force, just get a bigger hammer. Alternatively, you can look at enhancing performance with chemical means, and we don’t mean by using steroids. No, instead, you can try hammering with the aid of gunpowder, and [i did a thing] has done just that.

The build relies on using 6.8mm blank cartridges designed for the Ramset brand of explosive nail drivers. However, rather than buying such a tool off the shelf, [i did a thing] built one in a traditional hammer format instead. The device looks like a hammer, with a hinge on the two-piece head, which allows a blank cartridge to be placed inside. When the hammer is swung at a hard surface, the impact triggers the blank which drives the nail forward with incredible force.

[i did a thing] was able to pierce steel with the device, and sent a nail clean through a surfboard, too. It’s a very dangerous thing, so if you’re experimenting in this space, do be careful. Video after the break.

Continue reading “Building A Hammer Powered By Gunpowder” →

ddrysfeöd circuit art sound and light scultpture

Labyrinthian Circuit Sculpture Evokes Moods With Sound And Light

October 20, 2021 by Ryan Flowers 5 Comments

In a famous letter penned by Victorian era author Oscar Wilde, he wrote:

“Art is useless because its aim is simply to create a mood. It is not meant to instruct, or to influence action in any way. It is superbly sterile, and the note of its pleasure is sterility.”

We can’t help but wonder if [Eirik Brandal] was evoking such Wilde thoughts when he wrote to tell us about ddrysfeöd, an electronic sound and light sculpture which he called “uselessly applied electronics.” Given the mood created by the video below the break, we have to agree that it is indeed quite artful. But if it serves a purpose to inspire and cause wonderment, is it really useless? Let the philosophers philosophize. On to the hack!

[Eirik] was himself inspired by mazes such as those found in children’s activity books and magazines whose goal is to keep a child ~~busy~~ challenged by drawing a solid line from start to finish. With these in mind, [Eirik] constructed ddrysfeöd as an intricate entanglement of electronics, metal, clear and mirrored acrylic, and plated steel, all flung into a three dimensional vortex.

LED’s of red and white oscillate in time with each other. Orchestrating the multimedia symphony is an ESP32, with one core relegated to dealing with the mundane functions of the sculpture while the other waves its electronic wand to keep the ensemble suitably arranged. LED’s are bored into the base, and the acrylic is sanded on the edges to diffuse the supplied light. The electronics run on the usual +5 V, but a +12 V power supply gives volume to the LM380 audio amplifier. We also appreciated that [Eirik] expanded his skills on this project by using Sketchup to plan out the project, even printing the patterns for cutting and drilling the acrylic glass.

If [Eirik]’s build style looks familiar, it may be because you’ve seen it here on Hackaday’s Circuit Sculpture Contest, where some of his work was named Most Beautiful. You can also feast your eyes on a BEAM bot inspired pummer in the shape of a satellite. And remember, if you run across something that presses your buttons, let us know via the Tip Line!

Continue reading “Labyrinthian Circuit Sculpture Evokes Moods With Sound And Light” →

Tech In Plain Sight: Glucose Meters

October 20, 2021 by Al Williams 27 Comments

If you or someone you know is diabetic, it is a good bet that a glucose meter is a regular fixture in your life. They are cheap and plentiful, but they are actually reasonably high tech — well, at least parts of them are.

The meters themselves don’t seem like much, but that’s misleading. A battery, a few parts, a display, and enough of a controller to do things like remember readings appears to cover it all. You wouldn’t be surprised, of course, that you can get the whole affair “on a chip.” But it turns out, the real magic is in the test strip and getting a good reading from a strip requires more metrology than you would think. A common meter requires a precise current measurement down to 10nA. The reading has to be adjusted for temperature, too. The device is surprisingly complex for something that looks like a near-disposable piece of consumer gear.

Of course, there are announcements all the time about new technology that won’t require a needle stick. So far, none of those have really caught on for one reason or another, but that, of course, could change. GlucoWatch G2, for example, was a watch that could read blood glucose, but — apparently — was unable to cope with perspiration.

Even the meters that continuously monitor still work in more or less the same way as the cheap meters. As Hackaday’s Dan Maloney detailed a few years back, continuous glucose monitors leave a tiny sensor under your skin and measure fluid in your body, not necessarily blood. But the way the sensor works is usually the same.

For the purposes of this article, I’m only going to talk about the traditional meter: you insert a test strip, prick your finger, and let the test strip soak up a little bit of blood.

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Refining The Greatest Joystick Of The 1980s

October 20, 2021 by Tom Nardi 24 Comments

The Competition Pro joystick is often considered to be the pinnacle of input devices, at least as far as the 1980s gaming goes. But the design isn’t perfect, and time hasn’t been kind to certain aspects of its mechanism. For example, the large rubber disc used to keep the stick centered on early generations of the hardware will invariably be hardened up on any surviving specimens. Looking to return these classic controllers to their former glory, and then some, [mageb] has released a number of 3D printed modifications for the Competition Pro that should be of great interest to the vintage gamer.

First and foremost is the deletion of the original rubber disc for a new spring mechanism. Even if this is the only modification you do, [mageb] says you’ll already have a better and longer-lasting joystick to show for it. But if you want to continue with the full rebuild, be aware that there’s no going back to stock. Once you start cutting the original parts, you’re committed to taking it all the way.

Assuming you’re not afraid to get your hands dirty, the next step is cutting the metal contacts from the bottom of the face buttons so they’ll work with the new microswitch array he’s designed. Each button gets its switch, and four handle movement of the joystick. You can try out different switches to adjust the feel of the joystick, but [mageb] assures us that he’s already done the research and put the best quality switches in the bill of materials.

The end result is a Competition Pro joystick that looks more or less the same from the outside, but is considerably improved internally. That’s always a win in our books, though we’re sure somebody out there is going to get mad that the brittle old rubber disc wasn’t sent to the Smithsonian.

Know Audio: It All Depends On The DAC

October 20, 2021 by Jenny List 29 Comments

Our trip through the world of audio technology has taken us step-by step from your ears into a typical home Hi-Fi system. We’ve seen the speakers and the amplifier, now it’s time to take a look at what feeds that amplifier.

Here, we encounter the first digital component in our journey outwards from the ear, the Digital to Analogue Converter, or DAC. This circuit, which you’ll find as an integrated circuit, takes the digital information and turns it into the analogue voltage required by the amplifier.

There are many standards for digital audio, but in this context that used by the CD is most common. CDs sample audio at 44.1 kHz 16 bit, which is to say they express the level as a 16-bit number 44100 times per second for each of the stereo channels. There’s an electrical standard called i2s for communicating this data, consisting of a serial data line, a clock line, and an LRclock line that indicates whether the current data is for the left or the right channel. We covered i2s in detail back in 2019, and should you peer into almost any consumer digital audio product you’ll find it somewhere. Continue reading “Know Audio: It All Depends On The DAC” →

KiCad Team Releases Warning Regarding Domain Name

October 20, 2021 by Jim Heaney 23 Comments

On October 19th, [Seth_h] from the KiCad Project posted on the KiCad forums that the project’s original domain name kicad-pcb.org has been unexpectedly sold to a third party, and urged members of the community to avoid any links to this old website.

KiCad has used the domain kicad-pcb.org since 2012 as the official source for information on and downloads of their popular open-source electronics design software. Unfortunately, the original domain name was purchased before KiCad was formalized as an organization, so it was not directly under their control. This all came to head when the old domain name was unexpectedly sold to an unnamed third party that was not affiliated with the project. Currently, the old domain is just a website covered in ads, but the KiCad team fears that it may be used maliciously in the future.

With KiCad’s popularity, thousands of tutorials, articles, and project guides over the years have included links to the old KiCad domain. A Google search in October 2021 found more than 19,000 instances of the old domain spread across the internet. [Seth_h] has called upon the community to make every effort possible to update old links, reducing the chance that people stumble across the wrong website.

[Editor’s Note: We think we got ’em all, let us know if we missed any.]

Luckily, Digikey has swooped in to help save the day. They purchased a new domain, kicad.org, from squatters and donated it to the KiCad Project. (Update: Digi-key donated the KiCad.org domain back in October of 2020 after noticing fishy squatters going back to at least 2016) [Seth_h] explains in his post that a number of safeguards have been put in place to prevent this from happening in the future, including not having the domain name owned by a single person, and having all KiCad trademarks registered to the Linux Foundation.

There’s a good reason why KiCad has gotten so popular, it is packed full of great features for PCB design. Check out our coverage of some of the new features we are most excited for in KiCad 6.0 here.