A Different Sort of Word Clock

Our wonderfully creative community has a penchant for clocks. We have seen so many timepieces over the years that one might suppose that there would be nothing new, no instrument of horology that would not elicit a yawn as we are presented with something we’ve seen many times before.

Every once in a while though along comes a project that is different. A clock that takes the basic idea of a timepiece and manages to present something new, proving that this particular well of projects has not yet quite run dry.

Such a project is the circular word clock made by [Roald Hendriks]. Take a conventional circular wall clock and remove the hands and mechanism, then place LEDs behind the numbers. Add the words for “Quarter”, “Half”, etc. in an inner ring, and place LEDs behind them. Hook all these LEDs up to a microcontroller with a real-time clock, and away you go with a refreshingly novel timepiece.

[Roald]’s clock has the wording in Dutch, and the brain behind it is an Arduino Uno with the relevant driver ICs. He’s provided a video which we’ve put below the break, showing the clock in operation with its various demo modes.

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Start Your Path to Becoming an Antenna Guru

We’ve known a few people over the years that have some secret insight into antennas. To most of us, though, it is somewhat of a black art (which explains all the quasi-science antennas made out of improbable elements you can find on the web). There was a time when only the hams and the RF nerds cared about antennas, but these days wireless is everywhere: cell phones, WiFi, Bluetooth, and even RF remote controls all live and die based on their antennas.

You can find a lot of high-powered math discussions about antennas full of Maxwell’s equations, spherical integration and other high-power calculus, and lots of arcane diagrams. [Mark Hughes] recently posted a two-part introduction to antennas that has less math and more animated images, which is fine with us (when you are done with the first part, check out part two). He’s also included a video which you can find below.

The first part is fairly simple with a discussion of history and electromagnetics. However, it also talks about superposition, reflection, and standing wave ratio. Part two, though, goes into radiation patterns and gain. Overall, it is a great gateway to a relatively arcane art.

We’ve talked about Smith charts before, which are probably the next logical step for the apprentice antenna wizard. We also covered PCB antenna design.

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Hackaday Links: November 27, 2016

[Prusa]’s business is doing great. This year, he released the Prusa i3 Mk. 2, a four color upgrade to the printer, and sales are through the roof. There’s just one problem: Paypal just locked his funds. Prusa is turning away from Paypal and given Paypal’s history, this will eventually be worked out. Be warned, though: don’t use Paypal for your hardware business. We’ve seen this same story played out too many times before.

Those millennials are always on their phones. How do you get rid of that distraction? Airplane mode? No, that’s stupid. Put those phones in a metal box. It’s the exact same thing as airplane mode – which is free – but this extra special metal box costs $45 and ships in March. Is this metal box different from any other metal box, like a cookie tin, perhaps? Probably not.

Nothing to see here, folks.

The holidays are here, and it’s time for Cards Against Humanity to do something stupid with other people’s money. This year, they’re throwing money into a hole. No, really. People are contributing money to dig a gigantic hole. There’s a livestream of the digging. Five dollars lets the dig continue for another few seconds. Join in on the holiday spirit: throw your money into a hole.

You don’t want to throw your money into a hole? Buy some stuff on Tindie! There’s robots, CNC controllers, servo drivers, MIDI arpeggiators, USB testers, power supplies, blinky glowy things, and retro gaming stuff. Go plug your Raspberry Pi into some of these gizmos.

The Mechaduino is a board that clips onto a ubiquitous NEMA stepper motor to turn it into a servo motor.  It won 5th place in the Hackaday Prize last month, and we can’t wait to see it integrated into a closed-loop 3D printer. [Chris] came up with an Ethernet-enabled servo-stepper conversion, and now it’s a project on Kickstarter. Of course, you can buy a Mechaduino right now, making the future of stepper motor-controlled desktop CNC very interesting.

Individually addressable RGB LEDs exist, and we’re waiting for Clark Griswold to electrify his house in red, green, and blue. Until then, [Michel built a holiday ornament loaded up with 16 WS2812b LEDs. The star features caps and diodes to make everything work as it should and requires only three wires per star.

CNC Dummies for Routers

[This Old Tony] has a few videos that have made appearances on Hackaday. His latest one is CNC Dummies for Routers (see below). The subtitle, CNC Basics, is an honest one. If you’re already well versed in GCode and Mach 3, you probably won’t make it through the 14 minute video (although Tony is pretty entertaining even if you know what he’s talking about).

By his own admission, this is really CNC basics for hobby-grade CNC routers and mills. He starts off talking about his custom-built machine along with some common machines in the $500-$5000 range. He then gives a simple sketch of what GCode looks like.

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Sandwich Robot Keeps You Fed So You Can Keep Hacking

Food. A necessary — often delicious — interruption of whatever project you’re currently hacking away at. Ordering takeout gets expensive and it’s generally unhealthy to subsist solely on pizza. With the Sandwich-O-Matic, a simple voice command fulfills this biological need with minimal disturbance of your build time.

Built for a thirty-six hour hackathon, the Sandwich-O-Matic is controlled by a Photon and an Arduino. The backend is running node, hosted on AWS, and Google Cloud was used for voice to text recognition. This thing is a fully automated and voice controlled sandwich building station. A DC motor services the toaster, while the rest of the device is actuated by servos. Simply tap the ‘begin recording’ button on the site, tell it your ingredient choices, and off it goes.

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Control Anything with a Universal Wireless Remote

If you aren’t already living on the spacecraft Discovery One, you may not have HAL listening to your every voice command. If that’s the case for you, as it is for us, you may have to resort to mashing buttons on little black monoliths like a primitive monkey. [Barnr]’s universal remote project, and some black PLA filament, will get you there in no time.

2001_obeliskThe remote is based on a nRF24 radios with a PIC to read the button presses. A Raspberry Pi and another nRF24 are listening on the other end. The code that runs either side of the connection is so minimal that both sides fit in the project description. It gets the job done, and it’s easily hackable. And with that, [barnr] can control anything that he can connect up to the Pi without getting up from his campfire.

While [barnr] is shy about his 3D design skills, we think that the box is fantastic. It’s got 3D-printed keycaps for the tactile switches that sit inside, and it’s an easily printed case. Maybe it’s a little blocky and, frankly monolithic, but it gets the job done. Aesthetics are for version 2.0.

When you build something yourself, and it’s not a HAL 9000, you pretty much need a way to control it. It’s no wonder we’ve seen so many projects on Hackaday. If your 2.4 GHz spectrum is too crowded to run a nRF24 remote, you might consider infrared: tiny, tiny, infrared. Or if you want to see the craziest remote that we’ve ever seen, check out this DTMF-over-cellphone build. But if you just want something sweet and minimal that gets the job done, [barnr]’s build is for you.

Thanks [Mikejand] for the tip!

DIY Rocket Mass Heater Build Log For Commercial Greenhouse

[Bigelow Brook Farm] has a cool geodesic dome greenhouse that needs to stay warm in the winter. There are a lot of commercial solutions for greenhouse heating, but if you’re the kind of person who research and develops solutions for aquaponics, a greener solution may have more appeal.

A rocket mass heater is a combination of a rocket stove and underfloor heating. A rocket stove works by having such a strong draft created by the heat rising up the chimney that the flames can’t crawl up the fuel and burn in the open air, creating a controlled burn zone. Unfortunately, with just a plain rocket stove a lot of heat is lost to the atmosphere needlessly. You only need enough to create the draft.

The mass part solves this. It runs the exhaust under the floor and through radiators. This passively retains a lot of heat inside the space to be heated. It’s a bit of a trick to balance the system so it puts as much heat into the space as possible without stalling, which can be dangerous due to carbon monoxide, among other things. Once the balance is achieved the user gets a stove that can burn fuel very effectively and best of all passively.

[Bigelow Brook Farms] have been working on their heater for quite some time. We really enjoy their test driven development and iteration. They have really interesting autopsies when a component of the heater fails and needs replacing. Right now they have a commercial sized operation heated by their latest iteration and it’s completely passive, being gravity fed. Video after the break.

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