This film projecter is hiding an Arduino Uno that controls a water-based cooling system.

Cool The Shop With A Thermal Battery-Based System

January 1, 2022 by Kristina Panos 64 Comments

Having any kind of shop is pretty great, no matter how large it may be or where it’s located. If the shop is in an outbuilding, you get to make more noise. On the other hand, it will probably get pretty darn hot in the summer without some kind of cooling system, especially if you don’t have a window for a breeze (or a window A/C unit).

[Curtis in Seattle] built an awesome thermal battery-based cooling system for his shop. The battery part consists of five 55-gallon drums full of tap water that are connected in series and buried a foot underground, about two feet out from the wall. There are two radiators filled with water and strapped to 20″ box fans — one inside the shop, which sends heat from the shop into the water, and another outside that transfers heat out of the water and into the cool night air. Most summer days, the 800-square-foot shop stays at a cool 71°F (21.7°C).

We love that the controls are housed in an old film projector. Inside there’s an Arduino Uno running the show and taking input from four DS18B20 one-wire temperature sensors for measuring indoor, outdoor, battery, and ground temperatures. There are four modes accessible through the LCD menu — idle, cool the shop, recharge mode, and a freeze mode in case the outside temperature plummets. Why didn’t [Curtis in Seattle] use anti-freeze? It’s too expensive, plus it doesn’t usually get that cold. (Although we hear that Seattle got several inches of snow for Christmas.) Check it out after the break.

If you can’t just go burying a bunch of 55-gallon drums in the ground where you live, consider building a swamp cooler out of LEGO.

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A 3D-printed macropad that needs no solder or screws.

Snap-Together Macropad Does It Without Solder

December 29, 2021 by Kristina Panos 10 Comments

Maybe we’re biased, but we think everyone has a use for a macropad. It’s just a matter of time before a highly personalized set of speed controls starts to sound like a great time-saving device to have around.

Trouble is, macropads are usually kind of expensive to buy outright, and not everyone feels comfortable building keyboards. Okay, so what if you didn’t even have to solder anything? That’s the idea behind [Jan Lunge]’s hand-wired macropad.

You will still want to open a window for ventilation if you build this one, because this macropad requires a lot of 3D printing. What it doesn’t require is glue or screws, because everything snaps together.

Of course, the star of this build is [Jan]’s hot swap socket design. We especially love the little clip that holds the column wires in place while also providing a spacer between those and the row wires. Everything is connected up to a Pro Micro with non-insulated wire and held in place with bends at the ends and the magic of tension. Be sure to check out the build video after the break.

Thirsty for more than a six pack of switches? This design is easy to scale up until you run out of microcontroller inputs. At that point, you might want to add screens to keep track of all your macros.

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Turing Ring Is Compact

December 28, 2021 by Al Williams 2 Comments

One of the problems with a classic Turing machine is the tape must be infinitely long. [Mark’s] Turing Ring still doesn’t have an infinite tape, but it does make it circular to save space. That along with a very clever and capable UI makes this one of the most usable Turing machines we’ve seen. You can see a demo in the video below.

The device uses an Arduino Nano, a Neopixel ring, an encoder, and a laser-cut enclosure that looks great. The minimal UI has several modes and the video below takes you through all of them.

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Voice Command Made Mostly Easy

December 27, 2021 by Al Williams 19 Comments

Speech commands are all the rage on everything from digital assistants to cars. Adding it to your own projects is a lot of work, right? Maybe not. [Electronoobs] shows a speech board that lets you easily integrate 255 voice commands via serial communications with a host computer. You can see the review in the video below.

He had actually used a similar board before, but that version was a few years ago, and the new module has, of course, many new features. As of version 3.1, the board can handle 255 commands in a more flexible way than the older versions.

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An orange 3D printed four digit clock with rotating segments

Be Mesmerized By The Latest Time Twister

December 18, 2021 by Chris Wilkinson 16 Comments

[Hans Andersson] has been creating marvelous twisting timepieces for over a decade, and we’re pleased to be able to share his latest mechanical clock contraption with our readers, the Time Twister 5.

In contrast to his previous LEGO-based clocks, version five of the Time Twister uses 3D printed segments, undoubtedly providing greater flexibility in terms of aesthetics and function. Each digit is a mechanical display, five layers vertical and three segments horizontal, with a total of three unique faces. Each layer of each display can be individually rotated by a servo, and this arrangement allows for displaying any number between zero and nine. The whole show is controlled by an Arduino MEGA and a DS3231 real-time clock.

Watching these upended prisms rotate into legible fifteen-segment digits is enjoyable enough already, but the mechanical sound created by this timepiece in motion is arguably even more satisfying. Check out the video below to see (and hear) for yourself. If you want to build one yourself, all the details are here.

We last covered [Hans Andersson] and his very first Time Twister clock way back in November 2011. Since then we’ve come across many impressive mechanical clocks, like this seven-segment work of art. We’re constantly impressed by the outstanding craftsmanship of these mechanical clocks, and it’s inspiring to see one of our OG horologists back in the saddle once more.

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Arduino Drives Faux Spirograph

December 10, 2021 by Al Williams 11 Comments

The holidays always remind us of our favorite toys from when we were kids. Johnny Astro, an Erector set, and — of course — a Spirograph. [CraftDiaries] has an Arduino machine that isn’t quite a Spirograph, but it sure reminds us of one. The Arduino drives two stepper motors that connect to a pen that can create some interesting patterns.

The build uses a few parts that were laser cut, but they don’t look like they’d be hard to fabricate using conventional means or even 3D printing. The author even mentions you could make them out of cardboard or foamboard if you wanted to.

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Hackvent Calendar Will Open The Door And Get Your Kids Soldering

December 5, 2021 by Kristina Panos 1 Comment

Who says it’s too early to get in the holiday spirit? We say it’s not. After all, people need time to get in the spirit before it comes and goes. And what better way to count down the days until Christmas than an electronic Advent calendar?

[Tom Goff]’s kids had some pretty cool ideas for building a decoration, like a musical, lighted sleigh complete with robotic Santa Claus. While that’s a little much to pull off for this year, they did salvage the music and lights part for their Hackvent calendar.

There are 24 small LEDs for December 1st through the 24th, and a big white star for December 25th. Each day, the kids just push the button and the day’s LED lights up. On the big day, all the small lights cascade off and the white one lights up, then it plays Jingle Bells through a sound playback module.

Each LED is connected directly to an input on an Arduino Mega. While there are several ways of lighting up 25 LEDs, this one is pretty kid-friendly. We think the coolest part of this build is that [Tom] and the kids did it old school, with nails hammered into the laser-cut plywood and used as connection terminals. Be sure to check it out in action after the break.

The more time you have, the more you can put into your Advent calendar build. Like chocolates, for instance.

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