proximity

12 Articles

Retrotechtacular: A Closer Look At The VT Proximity Fuze

June 9, 2023 by 16 Comments

Here at Hackaday, our aim is to bring you only the freshest of hacks, which carries the burden of being Johnny-on-the-spot with our source material. So if something of obvious interest to our readers goes viral, we might just choose to skip covering it ourselves, figuring you all have probably seen it already. But, if we can dig a little deeper and bring extra value over and above what the viral content provides — well then that’s another story.

That’s pretty much the story behind the excellent video recently released by [Real Engineering] about “The Secret Weapon That Changed World War 2.” It concerns the VT series of proximity fuzes — it’s a legitimate alternate spelling of “fuse” if a somewhat archaic one — that were used for artillery shells and spin-stabilized rockets in World War II. The video gives an excellent overview of the development of the VT, which was used primarily in anti-aircraft artillery (AAA). The details about the development of the American VT fuze are excellent, although curiously there’s no mention that British experiments with a radio proximity fuze were part of the goldmine of information brought to America at great risk by the Tizard mission in 1940. While there has been plenty of contention about the exact role the British work played, it’s fair to say that it at least informed the development and fielding of the American VT fuze.

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Sneeze Into Your Hand, Not Your Elbow With This Nose-Shaped Sanitizer Dispenser

July 9, 2022 by 7 Comments

You’ve got to love a language like German, where not only is it possible for a word or two to stand in for a complex concept, but you don’t even need to speak the language to make a good guess at what it all means. Of course when your project is a giant nose that mock-sneezes sanitizer into your hands, it doesn’t really matter that you call it Der niesende Desinfektionsmittelspender. Humor based on bodily functions is, after all, the universal language.

Working knowledge of German or not, figuring out exactly what [Nina] is doing here isn’t too difficult. Judging by the video below and the build log, the idea is to detect the presence of a hand underneath the dispenser with a simple IR reflective sensor hooked to some kind of microcontroller — an ESP32 in this case. Audio clips of sneezes are stored on an SD card and played back through a small speaker, while a hobby servo pushes the button on an atomizer. It seems as if selecting the proper dispenser was the hardest thing about the project; [Nina] finally settled on a battery-operated mister that was just the right size to fit into the nose. Oh, didn’t we mention the giant, pink, 3D-printed nose that houses the whole thing? Sorry about that — it’s quite subtle and easy to miss.

Anyway, the whole project is a lot of fun and brought a genuine laugh when we saw it. It’s a clever way to poke gentle fun at the germaphobes who came up with other, less whimsical methods of dispensing hand sanitizer. But let’s face it, they ended up being proven pretty much on the mark about things.

Continue reading “Sneeze Into Your Hand, Not Your Elbow With This Nose-Shaped Sanitizer Dispenser” →

Maybe One Of The Most Adorable Obstacle Avoiding Robots You’ve Seen

July 12, 2020 by 2 Comments

We’re all pretty well-acquainted with the obstacle avoiding robot. These little inventions use a proximity sensor to detect an object in front of the robot, then circumvent the object accordingly. Brown Dog Gadgets’ little robot really caught our eye, mostly because it’s kind of cute.

This little robot combines a few LEGO pieces, Arduino, and Brown Dog Gadgets’ own in-house invention, Crazy Circuits. The LEGO pieces make up the body of the robot, craftily enclosing a small portable battery pack used to power the bot. Brown Dog Gadgets uses another home-grown design, their robotics controller board, breaking out a few GPIO pins of an Arduino-compatible microcontroller into LEGO-compatible connections. This makes it easy to interface two of our favorite DIY STEM tools using a solderless connection.

Add a few LEGO wheels and a caster for pivoting and you’ve got a pretty simple, little robot. Fortunately, Brown Dog Gadgets was very thorough in their write-up, so head on over to their Instructable for all the details.

In the meantime, we’ve got a rich history of obstacle-avoiding robots here on Hackaday. Take a look around.

Handwashing Timer Makes Sure The Suds Stay On Long Enough

March 19, 2020 by 21 Comments

“Twinkle, Twinkle, Little Star”? How we wonder why you’d resort to singing a ditty to time your handwashing when you can use your social isolation time to build a touch-free electronic handwash timer that the kids — and you — might actually use.

Over the last few months, pretty much everyone on the planet has been thrust into strange, new, and oftentimes scary practices to limit the spread of the SARS-CoV-2virus and the disease it causes, COVID-19. Judging by the number of people we’ve seen leaving public restrooms without a visit to the washbasin before the outbreak began — and sadly all too often since — we collectively have a lot of work to do in tightening up our handwashing regimens. Time on target and plenty of friction are the keys to that, and [Denis Hennessy]’s “WashTimer” aims to at least help you out with the former. His build is as simple as can be: an Arduino driving an LED matrix when a proximity sensor fires. Wave your dirty paws in front of the unit as you start to scrub up, and the display goes through a nicely animated 20-second countdown, at which time it’s safe to rinse off.

[Denis] purposely made this design as simple and as customizable as possible. Perhaps you’ve got a Neopixel ring lying about rather than the LED matrix, or maybe an ultrasonic sensor would work better for you. Be creative and take this design where it needs to go to suit your needs. We can’t stress enough that handwashing is your number one defense; if you don’t need to moisturize your hands at least three times a day, you’re probably not washing often or long enough. And 20 seconds is way longer than you think it is without a prompt.

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The Complete Beginner’s Guide To Building A CNC Machine

December 5, 2018 by 18 Comments

Despite appearances, [This Old Tony]’s latest series has little to do with CNC-ifying an Etch A Sketch. Although he certainly achieves that, more or less, automating the classic toy is just the hook for a thorough lesson in CNC machine building starting with the basics.

Fair warning: we said basics, and we mean it. [Old Tony]’s intended audience is those who haven’t made the leap into a CNC build yet and need the big picture. Part one concentrates on the hardware involved – the steppers, drivers, and controller. He starts with one of those all-in-one eBay packages, although he did upgrade the motion controller to a Mach4 compatible board; still, the lessons should apply to most hardware.

By the end of part one, the Etch A Sketch is connected to two of the steppers and everything is wired up and ready to go for part two, the first part of which is all about inputs and outputs. Again, this is basic stuff, like how relays work and why you might need to use them. But that’s the kind of stuff that can baffle beginners and turn them off to the hobby, so kudos to [Old Tony] for the overview. The bulk of the second part is about configuring Mach4 Hobby, with a ton of detail and some great tips and tricks for getting a machine ready to break some end mills.

For someone looking to get into a CNC build, [Old Tony]’s hard-won CNC experience really fills in the gaps left by other tutorials. And it looks like a third part, dealing with making all this into something more than an automated Etch A Sketch, is in the works. We’re looking forward to that.

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Touchless Shop Doors Over-Engineered To A Blissful Level

March 11, 2018 by 13 Comments

When [John Saunders] wanted an automatic door for his shop, rather than settle for a commercial unit, he designed and built a proximity-sensing opener to ease his passing. Sounds simple, right?

Fortunately for us, there are no half-measures at Saunders Machine Works, thanks to the multiple Tormach workcells and the people who know how to use them. The video below treats us to quite a build as a result; the first part is heavy on machining the many parts for the opener, so skip ahead to 8:33 if you’re more interested in the control electronics and programming.

The opener uses time-of-flight distance sensors and an Arduino to detect someone approaching, with a pneumatic cylinder to part a plastic strip curtain. [John] admits to more than a little scope creep with this one, which is understandable when you’ve got easy access to the tools needed to create specialized parts at will.

In the end, though, it works well for everyone but [Judd], the shop dog, and it certainly looks like it was a fun build to boot. [John]’s enthusiasm for mixing machining and electronics is infectious; check out his automated bowl feeder for assembly line use.

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Custom Sensor Head Turns 3D Printer Into Capacitive Scanner

January 13, 2017 by 25 Comments

The best thing about owning a 3D printer or CNC router may not just be what you can additively or subtractively create with it. With a little imagination you can turn your machine into a 3D scanner, and using capacitive sensors to image items turns out to be an interesting project.

[Nelson]’s scanner idea came from fiddling with some capacitive sensors at work, and with a high-resolution capacitance-to-digital sensor chip in hand, he set about building a scan head for his printer. In differential mode, the FDC2212 sensor chip uses an external LC tank circuit with two plain sensor plates set close to each other. The sensor plates form an air-dielectric variable capacitor, and the presence of an object can be detected with high sensitivity. [Nelson]’s custom sensor board and controller ride on a 3D-printed bracket and scan over the target on the printer bed. Initial results were fuzzy, but after compensating for room temperature variations and doing a little filtering on the raw data, the scans were… still pretty fuzzy. But there’s an image there, and it’s something to work with.

Need a slightly more approachable project to get your feet wet with capacitive sensors? Maybe you should use your phone’s touchscreen as a 2D-capacitive scanner.

[via r/electronics]