A LEGO Turing machine for [Alan]‘s centennial

2012 is the 100-year anniversary of [Alan Turing]‘s birth, and to celebrate the centennial, [Jeroen] and [Davy] over at Centrum Wiskunde & Informatica in The Netherlands built a Turing machine out of LEGO.

A Turing machine is an extremely simple device, but is still able to compute everything your desktop can. The machine is generally described as an infinite paper tape with a read/write head. On this paper tape, the numbers ’1′ and ’0′ are written. By precisely defining what the Turing machine should do when it comes across a ’1′ or ’0′, its able to do the same calculations as a laptop, albeit at a much slower rate.

The LEGO Turing machine has a series of pins signifying each bit. These pins are moved underneath a read/write head containing a light sensor and robotic arm. When a pin is down, the camera sees a dark spot signifying one state. When the pin is up, light reflects off a white LEGO piece signifying another state.

[Jeroen] and [Davy] built an IDE for their Turing machine, so if you’ve got a few LEGO NTX bricks lying around you can grab the Git and build your own. Check out the mini documentary after the break.

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Fast and easy solder paste stencils

If you’re making your own boards with SMD parts, you might want to get a solder paste stencil. Usually made of laser-cut mylar or extremely thin steel, these stencils allow you to squeegee solder paste onto your board’s pads and make assembly a whole lot easier. [Rochey] needed a stencil for a board he was working on, and lacking a laser cutter he turned to what he had available – a few bits of plastic and a CNC machine.

[Rochey] began making his stencils out of laminating pouches and an xacto knife. This worked well, but it was time-consuming, and a bit fiddly when cutting 1 mm square holes. To speed up the process, [Rochey] put one of these laminating pouches on his CNC machine, exported the ‘Top Cream’ layer in Eagle to the CNC software of his choice, and had his machine attack the plastic with a 1 mm drill bit.

To [Rochey]‘s surprise, everything went as planned; in five minutes, he had a stencil with perfectly accurate holes that masked off everything but the SMD pads.

Thanks [Fabien] for sending this one in.

Putting scores of Arduinos on the Internet with one router

Like many hackers of late, [Rick] has been experimenting with connecting Arduinos to the Internet with a disused WiFi router and an installation of OpenWRT. Unlike his fellow makers, [Rick] thought it would be wasteful to dedicate a single router to one Arduino project, so he used a small, low power wireless module to connect up to 30 Arduinos to the Internet.

Just as in a few recent builds (1, 2), [Rick] found an old Fonera router sitting in a box at his local hackerspace. After installing OpenWRT, [Rick] connected a very small wireless module to the router’s GPIO pins and patched the firmware to put an SPI bus on the router.

Now, whenever [Rick] wants to connect an Arduino project to the Internet, all he needs is a $4 radio module. This radio module connects to the router, and the router handles the networking requirements of up to 30 DIY projects.

If you’re looking to build an Internet-enable sensor network, we honestly can’t think of a better or cheaper way of going about it. Nice job, [Rick].

Emulating Mac System 7 on an Android device

Over on the 68kmla forums, a website dedicated to old Macs built before 1994, [zydeco] released his Android port of Mini vMac, a Macintosh Plus emulator that puts the power of a Motorola MC68000 processor and System 7 on any computer.

Unlike the original Macintosh, or the subsequent revision that bumped the RAM up to 512 kilobytes, the Mac Plus was actually useful. With the addition of a SCSI port and support for 4 Megabytes of RAM, it’s not only possible to browse the Internet, but also act as a server. There’s a reason [Sprite_tm] chose to rebuild one of these classic, all-in-one machines to act as a home server; they really do epitomize the elegant computers from a more civilized age.

68kmla user [FlyingToaster] even went so far as to put a Mac Plus in his nook touch. With this, he’s got a full-blown installation of System 7 running on an e-ink screen, complete with LemmingsGauntlet, and Tetris.

It should be possible to plug this emulated box into the Internet. Unfortunately, experience tells us it won’t be a very pleasant browsing experience outside Hackaday’s retro edition.

Lucid dreaming mask marries economy with comfort

Here’s an effort to make a cheap lucid dreaming mask that is also comfortable. The idea is in response to the goggles we saw in April (which would not be too comfortable to sleep in) and the wildly successful Remee (which has an $80 target price).

The mask itself is sewn from a child’s fleece blanket. Inside is a piece of foam cut from some recreation mat. You know, those squares made for a play area that connect together like a jigsaw puzzle. You may have already spotted the Arduino in the image above, but the project is designed to run from an AVR chip embedded in the foam. The design only uses three LEDs, which may or may not work for you — we’d guess it depends on how they line up with your eyes. The video after the break does a great job of illustrating each point in the construction.

If you’re looking for something less soothing and more recreational you could always try out these trippy goggles.

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