The charging station on the table, with twelve powerbanks plugged into it, charging. A small meter on the front panel shows 4.73 volts and 4.38 amps.

A Simple Charging Station For Twelve Powerbanks

July 25, 2022 by Arya Voronova 13 Comments

[jasonwinfieldnz] uses twelve small powerbanks day to day – powering LED strips around his trampoline, presumably, to avoid the mess of wires and make the assembly easily portable. However, if you have twelve powerbanks, you’ll find yourself hogging all the household’s microUSB cables every so often, as they eventually discharge. This was not good enough for our hacker, and he decided to build a charging station to refill them all at once.

If you need 5 volts and many amps, an ATX PSU isn’t your worst bet. From there, he only had to add twelve microUSB connectors to – and condensed the entire contraption into a beautiful charging station. For the microUSB part, he hacked some microUSB cable ends off and embedded them into the case. An embedded voltage and current module is of big help – letting you see at a glance when charging has really finished. Using copper tape as bus bars and banana plugs for charging input, this project is easy to build and solves the problem well.

The 3D printing files and cutting templates are right there on the project page, so if any of us hackers has a problem that twelve powerbanks could help with, [Jason]’s project is quite repeatable. If your devices are more diverse, you could use a pegboard to build a stylish charging station for them! If, on the other hand, you have a single device you need to plug multiple cords into, moldable plastic is there to help.

Hack Your Brain: Bionic Reading — Panacea Or Placebo?

July 23, 2022 by Al Williams 17 Comments

In the Star Trek episode Space Seed, [Khan] famously said, “Improve a mechanical device, and you may double productivity. But improve man, you gain a thousandfold.” Most of our hacks center on the mechanical or electromechanical kind, but we do have an interest in safely improving ourselves. The problem is that most of us don’t want to mess with our DNA or have surgery, so it sort of limits our options.

We are always interested in less invasive hacks, so we certainly took note of Bionic Reading. However, a recent paper claims to debunk the claims of benefits. The company promoting the technology claims a Swiss University study showed that while the results were not clear, “the majority had a positive effect.” They also claim, anecdotally, that the technique can help those with dyslexia. What’s the truth? We don’t know, but it is an interesting discussion to follow.

If you haven’t seen it before, Bionic Reading — which, by the way, may not be free to use — is a way of using a dark font to emphasize certain key parts of words. For example, you can read this article using Bionic Reading. [Daniel Doyon] analyzed reading by 2,074 testers and found that participants actually read slower when using the Bionic Reading technique.

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Golf Club Shooter Is Your Ballistic Friend On The Green

May 25, 2022 by Lewin Day 17 Comments

Golf is a sport that has always enjoyed a good gadget or eight. Whether it’s something to measure the wind, or the latest putter guaranteed to save your game, golf enthusiasts have always flocked to such toys. [Nick O’Hara] has something that might just be a little too exciting for the golf set, though, in the form of his golf club launcher.

The golf club launcher essentially takes the role of a normal golf bag, with a rotating magazine containing all the necessary clubs for a day out on the green. The magazine is rotated into position on request, and the required club is launched out towards the player thanks to a pneumatic cylinder fired at 120 psi. A compressor in the base keeps the system charged with air for repeated launches.

The launcher even has a voice assistant built in. Telling the caddy the distance to the hole, and variables like wind and elevation, allows the device to select the right club for the conditions before blasting it towards the player.

It’s a device that easily puts a smile on the face every time it launches a club. We’ve seen some other great golf hacks before, too. Video after the break.

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Why Get Dressed When There Are Software Pants?

May 12, 2022 by Kristina Panos 42 Comments

With so many of us working from home over the last two years, it’s really become apparent that people generally dislike sitting all day with pants on. Until such a utopian time when all clothing is considered unisex, and just as many men as women are kicking it in loose, flowing skirts and dresses, you may want to remember to actually wear something on your lower half, uncomfortable though pants may be. But there is another way — you could build [Everything Is Hacked]’s pants filter and continue to be a chaos agent. Check out the video after the break.

That’s right, whether you forego or just forget to dress yourself below the equator, the pants filter has you covered. It works like you might expect — machine learning tracks body landmarks and posture to figure out where your NSFW region is and keep it under wraps.

By default, it blurs everything below the belt, or you can draw on pants if you’re inclined to be in revealing tighty-whities and prefer more coverage. You can adjust the width of the pants to cover the covid-19 you may have put on since 2020, and even change the pants to match your shirt.

We love that [Everything Is Hacked] had the um, gumption to test the pants filter in public at what appears to be a local taco joint. After the first few rounds of weird looks, he switched to a pants moustache to save face.

Want to add even more fun to those boring video calls? Try connecting up some vintage hardware, or install a pull chain to end those sessions with a gesture that won’t get you fired.

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Fort Knutz – Squirrels Go All Mission Impossible

April 26, 2022 by Anne Ogborn 21 Comments

[Mark Rober] has a bird feeder in his back yard. Also, squirrels who eat the seed. So, as one does, he built a nine part squirrel obstacle course with a reward of walnuts at the end, and filmed them beating the course.

(Spoiler – this is all much better in the video, which we’ve placed below the break).

His four backyard squirrels enter a ‘Casino’ and avoid the plushie ‘security’. From there it’s across a rod mounted on bearings, leap into a crate under a helicopter, which zip-lines to a brick wall with randomly moving bricks, and into their hideout.

A squirrel at a model buffet in a casino — Security is about to get him.

The hideout elevator shaft leads to a sewer, which leads to the famous room from Mission Impossible where [Tom Cruise] has to avoid the floor, but to get to the hatch in the top they have to lower a ladder by ‘hacking into’ the control system (by pushing a keyboard shaped button) and lowering a rope ladder.

Next they go through a tube maze to a room full of laser beams (3D printer filament) and finally they can jump onto the platform with Fort Knutz. If they get the vault door open, they’re rewarded with a shower of walnuts.

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Learning Electronics By Just Doing It

April 25, 2022 by Ryan Flowers 33 Comments

Learning anything new, especially so broad and far reaching as electronics, can be hard. [IMSAI Guy] knows this because he gets asked regularly “how do I learn electronics?” Many of you reading this will have a few ideas to pass along (and we encourage you to share your take on it in the comments below) but there is an even greater number of people who are asking the same question, and [IMSAI Guy]’s take on it is one that this particular Hackaday writer can relate to.

The ARRL Handbook can be found at hamfests, radio clubs, libraries, or at arrl.org

According to [IMSAI Guy], an excellent place to start is the ARRL Handbook. The ARRL Handbook is an electronics and RF engineering guide published by the Amateur Radio Relay League in the US. It’s a wonderful reference, and past editions can be had very inexpensively and are every bit as handy. Many hams will have a copy they could be talked out of, and you can likely find one at your local library. Where to start in the Handbook, then?

[IMSAI Guy] recommend starting with whatever catches your fancy. As an example, he starts with Op Amps, and rather than diving straight into the math of how they work or even worrying to much about what they are- he just builds a circuit and then plays with it to intrinsically understand how it works, a “learn by doing” approach that he has found extremely helpful just as many of us have. We also appreciated is very straightforward approach to the math: Don’t bother with it unless you need to for some reason, and definitely don’t start by learning it first.

In fact, that same reasoning is applied to any subject: Learn it as you need it, and don’t start by learning but rather by doing. The learning will come on its own! Be sure to check out the entire video and let us know what you think, and how you approached learning electronics. Thanks to [cliff] for the great Tip!

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Our Favorite Things: Binary Search

March 16, 2022 by Elliot Williams 34 Comments

You might not think that it would be possible to have a favorite optimization algorithm, but I do. And if you’re well-versed in the mathematical art of hill climbing, you might be surprised that my choice doesn’t even involve taking any derivatives. That’s not to say that I don’t love Newton’s method, because I do, but it’s just not as widely applicable as the good old binary search. And this is definitely a tool you should have in your toolbox, too.

Those of you out there who slept through calculus class probably already have drooping eyelids, so I’ll give you a real-world binary search example. Suppose you’re cropping an image for publication on Hackaday. To find the best width for the particular image, you start off with a crop that’s too thin and one that’s too wide. Start with an initial guess that’s halfway between the edges. If this first guess is too wide, you split the difference again between the current guess and the thinnest width. Updated to this new guess, you split the differences again.

But let’s make this even more concrete: an image that’s 1200 pixels wide. It can’t get wider than 1200 or thinner than 0. So our first guess is 600. That’s too thin, so we guess 900 — halfway between 600 and the upper limit of 1200. That ends up too wide, so we next guess 750, halfway between 600 and 900. A couple more iterations get us to 675, then 638, and then finally 619. In this case, we got down to the pixel level pretty darn fast, and we’re done. In general, you can stop when you’re happy, or have reached any precision goal.

[Ed note: I messed up the math when writing this, which is silly. But also brought out the point that I usually round the 50% mark when doing the math in my head, and as long as you’re close, it’s good enough.]

What’s fantastic about binary search is how little it demands of you. Unlike fancier optimization methods, you don’t need any derivatives. Heck, you don’t even really need to evaluate the function any more precisely than “too little, too much”, and that’s really helpful for the kind of Goldilocks-y photograph cropping example above, but it’s also extremely useful in the digital world as well. Comparators make exactly these kinds of decisions in the analog voltage world, and you’ve probably noticed the word “binary” in binary search. But binary search isn’t just useful inside silicon. Continue reading “Our Favorite Things: Binary Search” →