Finally, A Differently Useless Machine

Traditionally, the useless machine is a simple one that invites passersby to switch it on. When they do, the machine somehow, some way, turns itself off; usually with a finger or finger-like object that comes out from the box in what feels like an annoyed fashion. Honestly, that’s probably part of what drives people to turn them on over and over again.

But [Bart Blankendaal] has managed to turn the useless machine on its head. When this machine is switched to the on position, unseen forces inside the box will spin the toggle switch around 180° to the off position.

What’s really happening is that an Arduino is getting a signal from the toggle switch, and is then rotating it on a ball bearing with a stepper motor driven through an H-bridge.

It shouldn’t be too hard to make one of these yourself, given that [Bart] has provided the schematic and STLs. If we weren’t living in such touchy times, we might suggest building one of these into your Halloween candy distribution scheme somehow. Sell the switch as one that turns on a candy dispenser, and then actually dispense it after three or five tries.

Many see useless machines as tangible examples of existential quandary. Here is one that takes that sentiment a bit further by snuffing out a candle.

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E-Textile Tools Get The Multimeter Hookup

[Irene Posch] has done some incredible work with knitted, crocheted, and fabric circuits — check out the crocheted ALUs and embroidered computer for starters. Now, it seems [Irene] is building up a how-to catalog of e-textile tools that can be easily connected to a multimeter.

So far, this toolbox includes a seam ripper and a crochet hook. The concept is similar for both — print out a handle and connect the tool to a banana jack that can then be connected to a multimeter. The crochet hook is simple: just print out the handle, jam the hook in one end, and stick a mini banana jack in the other end. They’re designed to butt up against each other and make a connection without wires.

Building the ripper takes a bit more effort. There’s another printed handle involved, but you must first free the seam ripper from its stock plastic handle and solder a wire to it. Then twist the other end of the wire around a banana jack and and put that in the other end of the handle.

It’s great to see a little bit insight into the troubleshooting tools of e-textiles, especially because they are all-around fiddly. It all starts with a circuit, so why not do your prototyping with a thread-friendly breadboard?

Wooden Disc Player Translates Binary Back Into Text

[jbumstead] used MATLAB to convert the text messages into binary to be cut out of the disk.
[jbumstead] wanted to demonstrate the idea of information-storing devices such as LPs, CDs, and old hard drives. What he came up with lies directly at the intersection of art and technology: an intricately-built machine that plays beautiful collaged wooden disks. Much like the media that inspired the Wooden Disk Player, it uses a laser to read encoded data, which in this case is short bits of text like “Don’t Panic”.

These snippets are stored in binary and read by a laser and photodiode pair that looks for holes and not-holes in the disk. The message is then sent to an Arduino Nano, which translates it into English and scrolls the text on an LED matrix. For extra fun, the Nano plays a MIDI note every time it reads a 1, and you can see the laser reading the disk through a protective acrylic shield.

Though the end result is fantastic, [jbumstead] had plenty of issues along the way which are explored in the build video after the break. We love it when people show us their mistakes, because it happens to all of us and we shouldn’t ever let it tell us to stop hacking.

If anyone knows their way around lasers, it’s [jbumstead]. We loved playing their laser harp at Supercon!

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Magnum Opus Keyboardus, Or Build Ad Infinitum?

It happens to pretty much everyone who gets into keyboards. No commercial keyboard can meet all your needs, so you start building them. Use them a while, find problems, build a new keyboard to address them. Pretty soon you think you have enough user experience to design the perfect keeb — the be-all, end-all magnum opus clacker you can take to the grave. This time, it happened to [aydenvis]. We must say, the result is quite nice. But will it still be perfect in six months?

As you might expect, this board uses an Arduino Pro Micro. We can’t say for sure, but it looks like [aydenvis] created a socket with a second Pro Micro board populated only with female header. That’s definitely a cool idea in case the board fails. It also has two rotary encoders and a pair of toggle switches to switch controller and secondary designations between the PCBs.

We like the philosophy at play in this 36-key ‘board that states that prime ergonomics come when each finger must only travel one key distance from the home row. This of course requires programming layers of functionality into the firmware, which is easy enough to set up, but can be tricky to memorize. One thing that will help is the color-coded RGB underglow, which we’re going to call sandwich glow because it is emanating from the middle of a stacked pair of PCBs floating on 7 mm standoffs. We only wish we could hear how loudly those jade Kailh choc switches can clack. The board files are up on GitHub, so we may just have to make our own.

Indeed, many keebs we see use a Pro Micro or two, but here’s a tasty split that runs on a Raspberry Pi Zero W.

Via reddit

Roll Your Own Heelys

Remember Heelys, the shoes with wheels in the heels? Just lift up your toes, and away you go. We were at least ten or fifteen years older than the target demographic, but got a pair anyway just to please our inner child and have some fun. Young kids would wear them everywhere and zip around inside stores to the annoyance of everyone but other young kids. We imagine some shopkeepers got to the point where they could spot the things as they walked in the door and nipped the skating party in the bud.

[DevNerd] has conceived of the ultimate plan: if you make your own Heelys, no one necessarily has to know unless you start rolling around. [DevNerd] started by cutting some large, 20mm-deep holes in the bottoms of a pair of Air Jordans and printed a sturdy wheel and a box frame for support.

Each wheel has a bearing on both ends that spin on a threaded rod. We’re not sure why [DevNerd] went with threaded rod, because it seems like that would prematurely wear out the frame box.

Don’t want to cut up your shoes, but want some sweet roller kicks for the daily commute down the hall? You could always make them out of pallet wood.

Digital Cribbage Board Saves Scores, Marriage

When [ccooper] told his parents he was gonna start up his electronics habit again, the last thing he expected was to save his parents’ marriage in the process. But as soon as he dropped this news, they made a special request: build us something to replace the multi-purpose manual cribbage board. It’s too ambiguous and starts too many arguments.

Cribbage is a card game that involves scoring based on hands. Traditionally, the score is kept with pegs on a wooden board with two or three sets of 60 holes. To build a digital cribbage board, [ccooper] decided to represent the positions on a field made from chained-together RGBW matrices.

These four matrices are run by an Arduino Nano Every and will display one of three scoring schemes that the parents usually play. A set of eight AA batteries ensures that Mum and Dad can play out in bright daylight and still see the LEDs. You can see how the brightness rivals the sun in the demo after the break. The code and Gerber files for the custom board are there if you want to make one for yourself, or know of another marriage that needs saving.

Every game deserves tidy record-keeping. If you’re more the RPG type, check out this amazing stat tracker made of stacked-up FR4 boards.

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Otis Boykin’s Precision Passives Propelled The Pacemaker

The simplest ideas can be the ones that change the world. For Otis Boykin, it was a new way to make wirewound precision resistors. Just like that, he altered the course of electronics with his ideas about what a resistor could be. Now his inventions are in everything from household appliances and electronics to missile guidance computers.

While we like to geek out about developments in resistor tech, Otis’ most widely notable contribution to electronics is the control unit he designed for pacemakers, which regulate a person’s heartbeat. Pacemakers are a real-time clock for humans, and he made them more precise than ever.

Street Smarts and Book Smarts

Otis Frank Boykin was born August 29th, 1920 in Dallas, Texas to Sarah and Walter Boykin. Otis’ father was a carpenter who later became a preacher. His mother Sarah was a maid, and she died of heart failure when Otis was only a year old.

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