Hackaday Links: Sunday, July 28th, 2013


[Chris Gammell] tipped us off that he’s building an online training program for learning electronics. The ten session course will cost money to take but you can get the goods for free if you’re one of the beta testers. We love to listen to The Amp Hour podcast which is just one of [Chris’] many endeavors.

Did you buy a Chromecast this week? We did, but we don’t have it in hand yet (ordered through Amazon). You can still get a look inside from the iFixit teardown.

Practice your Processing skills by using it to code a game of Pong.

A bit of lighter fluid and a hacked insert will get you a flaming wallet. We guess this is a different type of an anti-pickpocket device. [Thanks Stephen]

[Brain] used a $1.50 magnifying lens to help his Raspberry Pi camera module read QR codes better.

We really like [Aaron Christophel’s] LED matrix clock (translated). He started from a marquee that must be at least a decade old. He stripped it down and figured out how to drive it using a Sanguino as a controller.

GRBL compatible Arduino CNC shield

By the time you get to the point in a home CNC build where you’re adding control electronics you may be ready for the simplest means to an end possible. In that case, grab your Arduino and heat up that etching solution to make your own GRBL compatible shield.

This familiar footprint manages to contain everything you need for a three-axis machine. The purple boards slotted into the pairs of SIL headers are Pololu Stepper motor drivers. Going this route makes replacing a burnt out chip as easy as plugging in a new module. The terminal block in the center feeds the higher voltage rail necessary for driving the motors. The DIL header on the right breaks out all of the connections to the limiting switches (two for each axis), spindle and coolant control, as well as three buttons for pause, resume, and abort. There’s even a header for SPI making it easier to add  custom hardware if necessary.

This is a dual-layer board which may not be ideal for your own fabrication process. [Bert Kruger] posted his Gerber files for download if you want to put in a small run with OSH Park or a similar service.


Rekindling Forth with a Propeller Jupiter Ace


The Jupiter Ace was a small membrane keyboard, cassette tape drive computer akin to the ZX Spectrum released in 1982. Priced at £90, it was a little more expensive than its home computer contemporaries, but had a very interesting feature: instead of BASIC, the Ace ran Forth. This interpreted stack-based language is far more capable than the BASIC variants found on home computers of the day, but unfortunately the Ace failed simply because Forth was so foreign to most consumers.

Not wanting to let a good idea die, [prof_braino] is bringing Forth back into the modern age. He’s using a Parallax Propeller to emulate a simple home computer running Forth. Instead of a book-sized computer, the new Propeller version runs on a single chip, with 8 CPU cores running 24 times faster than the original, with 32 times more RAM and an SD card for basically unlimited storage.

Electric skillet reflow soldering guide


It’s no secret that we’re bizarrely drawn to macro videos showing solder paste during the reflow process. This electric skillet reflow guide provides the fix we’ve been jonesin’ for while including some helpful tips for first-timers and veterans alike. Not sure what we’re talking about? Look at the grey paste at the top of this image. As it heats up it’s drawn under each component as seen in the lower half of the image.

This particular guide is aimed at one-off assembly so a solder paste stencil is not used (we learned a lot about those earlier in the month). It instead uses the painstaking toothpick application technique. It takes time but the upside is that once you get the hang of it you’ll apply the perfect amount of solder each time. After placing all of the components [Count Spicy] carefully transfers the board to an electric skillet, covers it with the glass lid (so he can see what’s going on), and sets the temperature just above the solder’s specified melting point.

Since the skillet is cheap and easy to find you really just have to order the solder paste to get into this type of assembly. Our only gripe is that you can’t really follow a temperature profile with this rig. For that you need to move up to some PID controlled hardware.

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Turning Kerbal Space Program into a proper space simulator


Kerbal Space Program – the game of freakin’ space Lego and incompetent little green men – has seen a lot of popularity since it was on the Steam Summer sale. Now, in a bid to out do the flight sim aficionados who build 737 cockpits in their garage, a few enterprising Kerbalnauts are building custom controllers for this wonderful introduction to [Tsiolkovsky], [Goddard], and [Evel Kinevel].

[vladoportos] thought KSP could use custom gaming controllers to provide switches for staging, attitude hold, and reaction control system commands. In the game, these are toggled by keyboard input, but this unfortunately destroys the immersion of being a rocket-powered angel of death for your Kerbal volunteers. He rigged up an Arduino Leonardo to send USB HID commands to his computer whenever he pressed one of the buttons connected to his breadboard controller. It’s a work in progress, but [vladoportos] has some big plans that include a physical nav ball to show his ship’s orientation in space.

USB input is one thing, but that’s only half the problem. If you want to build a real Kerbal ship simulator, you’ll need to get data out of the game, and into your glass or analog displays. [voneiden] over on the KSP subreddit has the solution for you. He’s been working on a ‘mission control’ app that runs in Python, connects to a Kerbal Space Program plugin over TCP, and displays flight information such as speed, altitude, longitude, latitude, apoapsis, and periapsis.  The code is up on his git, ready for some individual to bring this over to a Raspi and a character LCD display.

Propane forge built from a soup can


It doesn’t look like much, but this easy to build propane forge is just what you need to try your hand at blacksmithing. [Code Cowboy] took on the build after watching this how-to video which shows the fabrication of a small knife after completing the forge build.

The first step is to eat all of the soup (or beans if you prefer). With an empty can in hand the stand — made of two angle brackets — and inlet are attached. Next comes the heat proofing for the walls of the forge. At first glance we thought that cat litter was one of the ingredients, but that’s just an empty container used to haul playground sand. The sand is mixed with equal parts of plaster of paris before adding water to achieve a clay-like consistency. This is packed into the can, with a small opening to receive the metal to be heated.

The torch itself can be used to cure the heat shield. After letting the mixture harden a 30 minute burn will force the rest of the water out of the heat proofing.

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