Hackaday Links: March 31, 2014

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Wanting to display his Google calendars [Chris Champion] decided to mount an old monitor on the wall. The hack is his installation method which recesses both the bracket and the outlet while still following electrical code (we think).

Since we’re already on the topic. Here’s a hack-tacular project which hangs a laptop LCD as if it were a picture frame. We do really enjoy seeing the wire, which connects to the top corners and hangs from a single hook a few inches above the screen bezel. There’s something very “whatever works” about it that pleases us.

[Jaspreet] build a datalogger in an FPGA. He put together a short video demo of the project but you can find a bit more info from his repo. He’s using a DE0-Nano board which is a relatively low-cost dev board from Terasic.

Want to see what’s under the hood in the processor running a Nintendo 3DS? Who wouldn’t? [Markus] didn’t just post the die images taken through his microscope. He documented the entire disassembly and decapping process. Maybe we should have given this one its own feature?

If you’re streaming on your Ouya you definitely want a clean WiFi signal. [Michael Thompson] managed to improve his reception by adding an external antenna.

We always like to hear about the free exchange of information, especially when it comes to high-quality educational material. [Capt Todd Branchflower] teaches at the United States Air Force Academy. He wrote in to say that his ECE383 Embedded Systems II class is now available online. All the info can also be found at his Github repo.

And finally, do you remember all the noise that was made about 3D printed guns a while back? Well [Mikeasaurus] put together the .iStab. It’s a 3D printed iPhone case with an integrated folding blade…. for personal protection? Who knows. We think it should be a multitasking solution that functions as a fold-down antenna.

Arduino Day is Today

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Did you know today is Arduino day? A day to pull that little teal board out of the bin and blink some LEDs or dive deeper to challenge your skills. There’s a map of local events, but unless you’re near Italy (the birthplace of the movement) events are a bit hard to find.

There can be a lot of hate for Arduino around here, but we consider it the gateway drug to learning hardware design so why not support wide-adoption of the platform? We’ve even seen Hackaday-associated projects adopting compatibility. Both the Mooltipass and the FPGA shield projects have the platform in mind. Break down the assumption that electronics require mythical-levels-of-wizardry to toy with and we’ll be on our way to a world filled with hardware hackers. If you do want to get some really cheap boards to hand out Sparkfun has Pro Mini’s for $3 today, as well as some other deals [Thanks Jeff].

Are you still unconvinced and ready to rage in the comments? Before you do head on over to our Arduino anger management site to exercise some of that aggression.

Sci-Fi Contest Prize Acquisition Issues — Oh Noes!

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We spent quite a bit of time picking out prizes for the Sci-Fi contest. But wouldn’t you know it, literally the day after announcing the contest we cued up The Amp Hour and heard about a worldwide stock shortage (34:00) of BeagleBone Black boards. About a week later Adafruit ran an explanation of the issues. It became clear why we were having issues sources a quintet of boards so that we could deliver on our prize offer.

To further compound problems we a somewhat smaller issue sourcing Spark Core boards. We put in an order for a quintet of them when we posted the contest; at the time they were supposed to be shipping in late March, but now shipping estimates have been delayed to mid-April. Assuming no more delays these should be available by the time the contest ends at the end of April so keep your fingers crossed.

We have a good relationship with the folks over at Spark Core and can probably ask them to help us out if we do get in a bind. But we don’t think anyone is going to be able to deliver the BeagleBone Black boards (which we have on backorder) in time for the end of the contest. So here’s the deal: if you win and really want these exact boards in the prize package you select, we’re going to do what needs to be done to get it for you, eventually. If you don’t want to wait and there is a suitable alternative we’ll make that happen.

We wondered what people are doing if they don’t want to wait out these shortages. Are there any other open-hardware projects that are similar in price and functionality? Our gut says no (that’s why they’re in such high demand). But we’d love to hear about some alternatives. Let us know by leaving a comment below.

Fail of the Week: Secret Agent-Style Book Hideaway

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Ah, the movies are an inspiration for so many projects. How many times have you seen a spy movie where a cutout in the pages of a book are hiding something? This was the inspiration which led [Paul] and his crew to try using a laser cutter to remove a handgun-shaped cutout from the pages. The fail began before the project even got started. The sacrificial book they had chosen was too thick to cut directly so they tore it in thirds for the cutting process.

The hijinks are portrayed well in the clip after the break. The infectious giggling as this first trace of the laser cuts the outline makes the video worth watching. As they try to go deeper, the success falls off rapidly. This makes for a great Fail of the Week discussion: Why can’t you cut through multiple layers of a book with a laser cutter? Is this merely a focal length issue that would be solved with a higher-end cutter or is there something else at play here. Let us know what you think by leaving a comment below.

 

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Retrotechtacular: The Magic of Making Cars in the ’30s

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We usually shy away from calling things ‘magic’ in our features because, you know… science. But in the case of this Chevrolet manufacturing reel from 1936 the presentation is nothing short of an industrialized version of The Sorcerer’s Apprentice. Well, not in the sense of mischief, but in that there is almost no explanation and the way the footage is laced together you get the strong feeling that, at the time, this type of industrialization was magic; a modern marvel. The techniques and skills of each worked passed down from a master to an apprentice but virtually unknown to the general public.

The clip, which is also embedded below, starts off in the machine shop where mold makers are getting ready to go into assembly line production. From there it’s off to the foundry for part casting and then into the stamping plant where white-hot (perhaps red-hot, but black and white film) metal is shaped by man-mangling presses. The image above follows the cast, stamped, and machined parts onto the assembly line. We like seeing a room full of pistons being QA checked by hand using a width gauge and micrometer.  The film continues through to the finished vehicle and we think you’ll agree there’s more than enough voyeuristic video here to overcome that lack of narration.

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First Stab at Motion Sensor to Disconnect a Car Charger

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[Pixel] just sent in this automotive hack which disconnects his car charger when the vehicle stops moving for at least 10 minutes. Why would you need such a thing? The 12V outlet in his vehicle isn’t disconnected when the ignition is turned off. If he leaves a charger plugged in when parking the car, he often returns to a drained battery.

The fritzing diagram tells the story of this hack. He’s using a 7805 to power the Arduino mini. This monitors an ADXL362 accelerometer, starting the countdown when motion is no longer sensed by that chip. At the 10-minute mark the N-channel MOSFET kills the ground side of the outlet. Good for [Pixel] for including a resetable fuse on the hot side. But it was the diode all the way to the left that caught our eye. Turns out this is part of a filtering circuit recommended in a forum post. It’s a Zener that serves as a Transient-Voltage-Suppression diode.

Another comment on that thread brings up the issue we also noticed. The 7805 linear regulator is constantly powered. Do you think putting the uC into sleep and leaving the linear regulator connected is an adequate solution? If not, what would you do differently?

Bookworm Playing Bot Tests Programmer’s OCR Skills

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Check out this brainy bot with [Jari] whipped up to dominate the Bookworm Deluxe scoreboard. The bot runs on top of a win32 machine, pulling screenshots to see the game board and simulating mouse clicks to play. The video after the jump shows that it plays like a champ, but it took some doing to get this far and [Jari] took the time to share all of the development details.

The hardest part of writing these types of bots is recognizing the game pieces. Check out all of the animation that’s going on in the still shot above… a lot of the tiles are obscured, there are different colors, and the tiles themselves shift as the bot spells and submits each word.

After some trial and error [Jari] settled on an image pre-processor which multiplies pixel values by themselves four times, then looks at each pixel with a 1/6 threshold to produce a black and white face for each tile. From there a bit of Optical Character Recognition compares each tile to a set of known examples. This works remarkably well, leading into the logic and dictionary part of the programming challenge.

Do you think this was easier or harder than the Bejeweled Blitz bot. That one was looking for specific pixel regions, this one is basically a focused roll-your-own OCR script.

 

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