A Better Expanding Table

December 27, 2015 by Brian Benchoff 15 Comments

About a year ago, [Scott] completed what is probably one of the finest builds ever shown on a YouTube channel. It was an expanding wooden table, a build inspired by a fantastically expensive expanding table that was itself inspired by a creation by a mad woodworker in the early 1800s. Although [Scott]’s table is a very well-engineered build, there were a few things he wasn’t happy with. Over the past few months he’s been refining the design and has come up with the final iteration – and plans – for a wooden mechanical expanding table.

Late last year, [Scott] had about 450 hours of design and build time in his table, and by the time he got to the proof of concept stage, he simply ran out of steam. Another year brings renewed enthusiasm, and over the past month or so he’s been working on much-needed improvements to his expanding table that included a skirt for the side of the table, and improvements to the mechanics.

The expanding table is rather thick with three layers of tabletop stacked on top of each other, and those exposed mechanical linkages should be hidden. This means a skirt, and that requires a huge wooden ring. [Scott] built a ring 5 1/2″ deep, about an inch and a half thick, and has the same diameter of the table itself. This means cutting up a lot of plywood, and stacking, gluing, sanding, and routing the entire thing into a perfectly round shape.

The other upgrades were really about the fit and finish of the internal mechanics of the table. Screws were changed out, additional brackets were crafted, and the mounts for the internal ‘star’ was upgraded.

After all that work, is the table done? No, not quite; the skirt could use a veneer, proper legs need to be built, and the entire thing could use a finish. Still, this is the most complete homebuilt expanding table ever conceived, and [Scott] has the plans for his table available for anyone who would want to replicate his work.

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Let Alexa Control Your Life; Guide To Voice-Enable Everything

December 26, 2015 by Mike Szczys 21 Comments

Let’s face it, automation doesn’t feel quite as futuristic unless you can just say what you want out loud and have the machines flawlessly obey. That is totally possible now — and on the cheap. Well, cheap as far as money goes. It can be an expensive learning curve to get it all working. This will help. [Lindo St. Angel] has put together a guide to navigate voice control of hardware using Amazon’s Alexa SDK.

We previously reported that Amazon’s AI had escaped its hardware prison in the form of the Alexa Skills Kit. Yes, calling it the Alexa SDK above is wrong it’s actually the ASK but nobody knows what that acronym is while most recognize the gist of an SDK. It gives you the hooks and the documentation necessary to leverage the functionality in your own applications. The core functionality of Alexa is voice recognition. Even so, it’s still a tall hill to climb.

[Lindo] has broken down the problem into a very manageable example. The Amazon Voice Service (part of ASK) is used for voice recognition and control. Amazon’s Lambda service connects the ASK to your piece of hardware; in this case he’s using a Raspberry Pi as the server. The final step is to connect your hardware to the Pi. [Lindo] is interfacing a keypad-based home automation system with the Pi but the sky’s the limit at this point.

With all the authentication and connectivity laid bare, this is a lot more approachable. The question is no longer can you connect everything to voice control. The question becomes should you give control of everything over to one single online service?

RGB LED Ceiling Display

December 20, 2015 by Anool Mahidharia 8 Comments

Disco Floor’s are passé. [dennis1a4] turned them upside down and built an awesome RGB LED ceiling display using some simple hardware and a lot of elbow grease. His main room ceiling was exactly 32 ft x 20 ft and using 2 sq. ft tiles, he figured he could make a nice grid using 160 WS2812B RGB LEDs. A Teensy mounted in the ceiling does all the heavy lifting, with two serial Bluetooth modules connected to it. These get connected to two Bluetooth enabled NES game controllers. Each of the NES controller is stuffed with an Arduino Pro Mini, a Bluetooth module, Li-Ion battery and a USB charge controller.

Bluetooth is in non-secure mode, allowing him to connect to the Teensy, and control the LEDs, from other devices besides the NES controllers. The Teensy is mounted at the centre of the ceiling to ensure a good Bluetooth link. Programming required a lot of thought and time but he did manage to include animations as well as popular games such as Snake and Tetris.

The hard part was wiring up all of the 160 LED pixels. Instead of mounting the 5050 SMD LED’s on PCBs, [dennis1a4] wired them all up “dead bug” style. Each pixel has one LED, a 100nF decoupling capacitor, and 91 ohm resistors in series with the Data In and Data Out pins – these apparently help prevent ‘ringing’ on the data bus. Check the video for his radical soldering method. Each SMD LED was clamped in a machine shop vice, and the other three parts with their leads preformed were soldered directly to the LED pins.

The other tedious task was planning and laying out the wiring harness. Sets of 10 LEDs were first wired up on the shop bench. He then tacked them up to the ceiling and soldered them to the 14 gauge main harness. The final part was to put up the suspended ceiling and close the 2 sq. ft. grids with opaque plastic.

[dennis1a4] did some trials to figure out the right distance between each LED and the panel to make sure they were illuminated fully without a lot of light bleeding in to adjacent panels. This allowed him to get away without using baffles between the tiles.

Check out the video to see a cool time-lapse of the whole build.

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Toilet Automatically Flushes For Your Bathroom Trained Kitty

December 16, 2015 by James Hobson 20 Comments

So you’ve successfully taught your cats to use your toilet, just like little furry humans. Congratulations! But you can’t quite teach the cat to pull the flush lever? You might want to automate it for them instead! (Editor’s note, 2019. Link seems to be dead. Try the Wayback Machine.)

[Joycelin & Dan] are in the final stages of teaching their cats to use the toilet. Unfortunately they had a snowboarding trip coming up, and were worried about the cats losing progress when they couldn’t flush the toilet for them. Rather than have a bit of a setback in their toilet training, they improvised — and automated the toilet.

There are commercial solutions available, but they cost several hundred dollars. You could strap a geared motor to the side of your toilet with a stick screwed to it like this guy did, but who wants to pay for the water bill of flushing your toilet every few minutes??

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Small-farm Automation Keeps Livestock Safe And Happy

December 15, 2015 by Dan Maloney 15 Comments

Life down on the farm isn’t easy, and a little technology can go a long way to making things easier for the farmer. It’ll be a while before any farmer can kick back on the beach and run his place from a smartphone, but that’s clearly the direction things are heading with this small farm automation project.

[Vince]’s livestock appears to consist of chickens and sheep at this point, and the fact that they share housing helped him to deploy some tech for both species. The chickens got an automated door that lets them out in the morning and shuts them in safely once they’ve returned to roost for the night – important protection against predators. The door is hoisted by a Somfy window-treatment motor, which seems a little on the overkill side to us; a thrift-store electric drill and a homebrew drum might have worked too. A Teensy with an RTC opens and closes the door according to sunrise and sunset times, and temperature and humidity sensors provide feedback on conditions inside the coop. The sheep benefit from a PTZ webcam to keep an eye on their mischief, and the whole thing is controlled by a custom web interface from [Vince]’s smartphone.

There’s just something about automating chicken coop doors that seems to inspire hackers; check out this nice self-locking design. As for [Vince]’s farm, it looks like his system has a lot of room for expansion – food and water status would be a great next step. We’re looking forward to seeing where he goes from here.

Spectacular View Of The Eiffel Tower Is All Done With Mirrors

December 14, 2015 by Dan Maloney 57 Comments

What Parisian wouldn’t want an apartment with a view of the Eiffel Tower? Alas, not every window can face the famed landmark, and for some, the million Euro view is tantalizingly out of reach. Such was the case for [Lurluberlu], but with a little optical trickery he was able to peer around a corner to deliver spectacular views of the Eiffel Tower to his bedroom.

[Lurluberlu] devised a simple horizontal periscope using two full-length mirrors. The video after the break shows the build – as a side note, we’re very jealous of his hand tool packed workshop. With some plywood backing and simple swivels, the mirrors were mounted on his window sill to bounce the iconic tower’s image inside. After a little adjustment, the image is perfectly framed by the window, and with the lights off in the apartment, the view from the bed is quite spectacular. Our bet is that it’s quite a bit cheaper than moving to a flat with a better view.

Of course, with a little ingenuity (and a balcony) anyone can have a view of the City of Light. Or anywhere else for that matter.

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Quick Network Bridge Gets Off-grid Home Back Online

December 9, 2015 by Dan Maloney 40 Comments

Off-grid living isn’t for everyone, but it has gotten easier in recent years. Cheap solar panels and wind turbines let you generate your own power, and there are plenty of strategies to deal with fuel, water and sanitation. But the one thing many folks find hard to do without – high-speed internet access – has few options for the really remote homestead. [tlankford01] wants to fix that and is working on an open-source mesh network to provide high-speed internet access to off-grid communities.

But first he had to deal with a major problem. With high-speed access provided by a Clearwire wireless network, streaming content to his two flat-screen TVs wasn’t a problem. At least until Sprint bought Clearwire and shut down the service in early November. Another ISP covered his area, but his house lies in a depression out of line of sight of their tower. So he rigged up a bridge between the WiMAX network and his lab. The bridge sits on a hill in sight of the ISP’s tower 3.5 miles away. Solar panels, a charge controller and deep-cycle batteries power everything, and a wireless link down the hill rounds out the build.

This is obviously a temporary solution, and probably wouldn’t last long in winter weather. But it’s working for now, and more importantly it’s acting as proof of concept for a larger mesh system [tlankford01] has in mind. There are plenty of details on what that would look like on his project page (linked above), and it’s worth a look too if you’re interested in off-grid connectivity.