Cobalt RaQ Retrofit Help Geek Up Your Entertainment Center

February 10, 2014 by 20 Comments

cobalt-raq-jukebox

Even network engineers who toil away in hot server rooms (which aren’t actually all that hot because they’re well climate controlled) deserve nice things. That’s why Cobalt came out with these gorgeous front bezels for their rack mounted equipment… around twenty years ago. [Geekmansworld] is reviving the look, but he’s not hiding it away in a server rack. He scrapped the guts and used the front bezel and controls as part of his media server.

His first new addition to the case was a pair of hard drives which connect to an eSATA hub also stored in the enclosure. He buttoned it up and gave it a test run. Everything worked smoothly and he hopes that it will continue that way without overheating when the summer rolls around again.

Of course a dead front bezel is no fun so he cut off the portion of the original circuit board which hosts the buttons seen on the right. These buttons now connect to a U-HID board which turns the button presses into mouse or keyboard inputs using a USB connection. The original display was swapped out for a backlit character LCD. The LEDs to the left are a refit which turns the status indicators into a VU-Meter. See the entire thing at work after the break.

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Python With Braces

February 10, 2014 by 110 Comments

python

If there’s one thing about Python that’s slightly disconcerting, it’s the complete lack of braces, or as they’re called in American English, suspenders. A feature of every variety of C, Java, PHP, Perl, and a whole bunch of other very powerful languages, braces make things more legible and don’t rely on precise indentation. [Ruby] and [Eran] have come up with a way to use these punctuation marks with Python in a project they call Python with Braces.

As its name implies, Python with Braces doesn’t care about indentation: you’re free to make you code extremely ugly, or write your code properly in K&R style. Each line is terminated in a semicolon, and blocks of code with only one statement don’t require curly braces, just like C and Java.

Right now [Ruby] and [Eran] have a Windows installer with an OS X package on its way. Executing a Python with Braces script only requires executing it with a ‘pythonb’ executable instead of the normal ‘python’ executable.

Java Grinder Spits Out DsPIC And MSP430 Assembly Code

February 10, 2014 by 13 Comments

java-code-grinder

[Michael Kohn] sent in a link to the set of projects he’s been working on lately. The Java Grinder is a project that converts Java code for use on microcontrollers. This actually started back in 2009, when he mentioned that the project was worthless because there were already a ton of Java virtual machines out there. But if he had really thought that he’d never learn anything. We’re glad [Michael] picked this back up and made something out of it.

The image above shows the proof of concept. It’s a box bouncing around the Nokia 6100 screen. He wrote the animation in Java, and used his grinder to turn the code into dsPIC assembly, which was then compiled and flashed onto the microcontroller. That’s not all, he’s also coded a Mandelbrot set generator or the same hardware. As it stands he can also produce assembly code for use on MSP430 chips.

This kind of exploration is great for the brain. We see it as a natural extension of the learning you acquire from Nand2Tetris which walks through the essential text The Elements of Computing Systems. If you’re not familiar, that’s a trip from building your first logic gate, which you plunk together with others to build an ALU, then start coding all the way up to a virtual machine to run on your simulated hardware.

Video of the bouncing box and Mandelbrot set is below.

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Controlling Motors Without A Microcontroller

February 10, 2014 by 63 Comments

serial

Think you need a microcontroller or a proper motor driver to control a motor? Not really. Because RS-232 serial ports are a hack in and of themselves, you can control two motors with only a serial port and a bridge driver.

Instead of using the data pins on the serial port, this circuit works on with the DTR and RTS control signals of an RS-232 interface. Unlike the data lines of a serial port, these control signals are high when they’re enabled and can also provide a small amount of current – enough to control a pair of pins on a TA7291P bridge driver.

The rest of the circuit consists of a few resistors and a pair of motors, and the software simply turns the DTR and RTS lines on and off. It’s enough for a small robot to waddle across a table, and given the correct driver is simple enough to mash together out of parts from a junk drawer.

The Two Component Random Number Generator

February 10, 2014 by 41 Comments

attiny10

[Karl] was in need of a hardware random number generator, but is needs had a few caveats: it needed to be cheap, and sufficiently random. Random number generation can get quite crazy with Geiger tubes, lava lamps, and radioactive decay, but a much smaller solution was found in an 8 pin AVR microcontroller.

The solution uses AVRentropy, a library that uses the watchdog timer’s jitter in AVR microcontrollers to provide cryptographically secure random numbers. Setting up the circuit was easy – an ATtiny45 microcontroller was connected to a cheap chinese USB to serial converter. Three wires, and the circuit is complete. The code was simple as well; it’s just a call to initialize the entropy and write the bits to the serial port.

There are a few drawbacks to this build. Because the entropy library must wait until enough entropy is gathered, it can only produce about two 32-bit numbers per second. That’s all [Karl] needed for his application, though, and with an enclosure made from a wine cork and marble, he has the prettiest and smallest random number generator around.

Wow. Such Mining Rig. So Amaze.

February 10, 2014 by 67 Comments

After hearing about cryptocurrencies like Bitcoin, Litecoin, and Dogecoin, [Eric] decided he would have a go at designing his own mining rig. The goals of the project were to have a self-contained and stackable mining rig that had all the parts easily accessible. The result is this awesome computer enclosure, where GPU mining and traditional woodworking collide.

For mining all those coins, [Eric] is using five R9 280x GPUs. That’s an impressive amount of processing power that ended up being too much for the 1500W power supply he initially planned to use. With a few tweaks, though, he’s managing about 2.8 Mh/s out of his rig, earning him enough dogecoins to take him to the moon.

In the video below, you can see [Eric] building his rig out of 4×8 framing lumber. This isn’t a slipshod enclosure; [Eric] built this thing correctly by running the boards through a jointer, doing proper box joints with this screw and gear-based jig, and other proper woodworking techniques we don’t usually see.

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7-Foot DIY Wind Turbine Proves Size Matters

February 10, 2014 by 15 Comments

7ft-wind-turbine

When [brokengun] decided to build a 7 ft diameter wind turbine, he had no idea how to even start, so he did as most of us would do and read some books on the topic. His design criteria was that it would be simple to construct and use as many recycled parts as possible. This wind turbine charges a 12 volt battery which can then be used to power a variety of gadgets.

Although made from recycled components, this isn’t a thrown together wind turbine. A lot of thought went into the design and build. [brokengun] discusses matching the blade size to that of the generator in order to maximize power and efficiency.  The design also incorporates a feature that will turn the turbine perpendicular to the wind if the wind-speed gets to high. Doing this prevents the turbine from being damaged by strong gusts.

For the main support/hub assembly, a Volvo 340 strut was used because they are widely available, cheap and known for being long-lasting. The tail boom is made from electrical conduit and it’s length is determined by the size of the main fan rotor. The tail vane is made from steel sheet metal and its surface area is also dependent on the fan rotor size to ensure that the turbine functions properly. The blades are made from wood but instead of making them himself, [brokengun] felt these were worth ponying up some cash. [brokengun] also scored a 30 ft high lattice tower an airport was getting rid of. This worked out great as it’s just the right height for a turbine of this size.

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