Month: October 2011

Halloween Hacks: Arc Reactor Costume

October 28, 2011 by 4 Comments

Halloween is the time of year where you can dress up as a pirate, muppet, or superhero and no one will bat an eye. During this holiday of expanded social permissiveness, [Nbitwonder] decided that building an Arc Reactor from Iron Man would be appreciated by his engineering cohort.

The ‘body’ of the reactor was manufactured on the RepRap Mendel we covered from beginning to end. A few minutes with Google Sketchup was all that was needed to generate the files and send them to the printer. In a few short hours, [Nbitwonder] had the body of his Arc Reactor.

The board design was thrown together in Eagle and etched. 11 blue SMD LEDs were thrown into the mix along with some borrowed resistors. Pieces of a hard drive spindle and a little bit of wire rounded out the parts list, and everything was assembled with the DIYers favorite tool, the hot glue gun. Not a bad job for a few hours of work.

The files for the Arc Reactor are up on Thingiverse along with a Flickr photoset.

Motor Drivers: Half H-bridge With Brake And More

October 28, 2011 by 11 Comments

Here’s a nice little circuit that will drive a motor and allow you to stop its rotation, giving your robot a set of brakes. It’s part of [JM’s] post about the in’s and out’s of building microcontroller friendly motor controllers (translated).

This particular setup is a half H-bridge. It allows you to drive the motor in one direction only. The MOSFET used on the ground-side of the motor doesn’t actually need to be there. This is the brake which let you electronically stop the motor from spinning. Without it, the motor will keep turning under its own momentum when the half-bridge is shut off. Depending on the application this can be a big problem. There’s a great demonstration of the circuit braking a fast spinning motor in the video clip below the fold.

It is possible to use this driver with PWM, but [JM] has some warnings about inbuilt functions like FastPWM. Make sure you read his admonition, and if you need a refresher don’t miss this Hackaday video segment.

Continue reading “Motor Drivers: Half H-bridge With Brake And More” →

The Basics Of Reading Data From Resistive Touchscreens

October 28, 2011 by 5 Comments

[Chris] just posted his latest tutorial which shows you how to read position data from a resistive touchscreen. These devices are fairly simple, and since they’re used in a lot of consumer electronics you can pick one up for a few bucks. This looks like it is overstock for an old Palm device.

The interface is simple, there’s just four conductors on the tab at the top of the overlay. But connecting to these is a bit of an issue since you can’t really solder directly to them. [Chris] ended up using scotch-tape to hold wires in place, with a paperclip to keep them presses against the conductors. Those conductors are used in pairs, with a positive and negative lead for the X and Y axis. To take a measurement you use I/O pins to connect voltage and ground, then read the voltage that makes it to the gound side using an ADC. This works because the point that’s being pressed on the screen acts as a variable resistor for the circuit. Data for the two axes must be read in separate operations so that the positive voltages don’t interfere with each other.

The nice thing is that once you’ve got it working with a small screen it is easily scaled up. In fact, the 23″ touchscreen used on this Android hack is just another 4-wire resistive device.

You can see a video demonstration of [Chris’] test rig embedded after the break.

Continue reading “The Basics Of Reading Data From Resistive Touchscreens” →

Detailed Tutorial Shows How To Unleash Your Inner [Michael Knight]

October 28, 2011 by 12 Comments

developing_a_larson_scanner

Our own [Mike Szczys] recently sat down and put together a great tutorial on building a Larson Scanner. The ubiquitous circuit is usually one of the first few projects on a budding hackers list of things to build, since they are just so darn fun.

Simple versions of the scanner sweep back and forth lighting the LEDs without any sort of transition between them. The configuration most familiar to us all as featured in Knight Rider and Battlestar Galactica are a bit more complex, and have a fading trail of light that follows behind the leading edge of the sweep. [Mike] notes that this fading is traditionally accomplished through the use of capacitors, which cause the light to gradually fade as the animation sweeps across the LED array. He decided to take a different route with his circuit, relying on PWM control of the LEDs instead.

Mike put together a simple circuit using an ATmega168, a handful of resistors, and of course, an array of LEDs. Utilizing interrupts and PWM, he was able to accurately recreate the iconic light sweep without the use of any capacitors. One big benefit to his design aside from the lower component count is the fact that he can easily adjust the speed of the sweep as well as the fading properties with a few small code tweaks.

Be sure to check out his blog at some point, where he shares his code, some circuit diagrams, and plenty more details on how his scanner was built. In the meantime, take a look at the video below to see the result of [Mike’s] work.

Continue reading “Detailed Tutorial Shows How To Unleash Your Inner [Michael Knight]” →

Halloween Hacks: A Light And Music Show Fit For [Jack Skellington]

October 28, 2011 by 4 Comments

Halloween Hacks Banner

singing_pumpkin_halloween_show

[Greg] was looking for something to build using his recently acquired Arduino, and with Halloween approaching, he thought a cool light display would make a great project. He browsed around online and found this tutorial that shows how to build a chorus of singing pumpkins controlled by a computer’s parallel port. Since he didn’t have any computers with a parallel port kicking around anymore, he decided to try his hand at recreating it with an Arduino.

[Greg] gathered eight light up Jack-o-Lanterns, along with a handful of relays and other miscellaneous components. He wired up the relays to trigger each individual pumpkin’s built in light when switched by the Arduino. He sat down and carefully listened through “This is Halloween” from The Nightmare Before Christmas, choreographing each of the pumpkins to take on the voice of one of the movie’s characters.

When the show begins, the display transforms from a group of unassuming pumpkins with candles a-flicker to a chorus of ghouls extolling the virtues of Halloween.

It really is fun to watch, so be sure to check out the video below. If you’re looking to throw together a quick display before the big day rolls around, [Greg’s] source code and diagrams should get you headed in the right direction.

Continue reading “Halloween Hacks: A Light And Music Show Fit For [Jack Skellington]” →

You Probably Do Not Have Time To Build This Incredible Dead Space Costume.

October 28, 2011 by 7 Comments

What happens when an unemployed sailor has a ton of time on his hands? Well, evidently they become an extremely skilled prop builder. Then again our only reference point is [Throssoli]’s excellent Dead Space suit build.

[Throssoli] started this ambitious project by setting a months deadline for the helmet. Although he did not meet the dead line the results were fantastic and very true to the game models.  Noting the reaction people had to the helmet out in the wild, and giving in to the fact that he really wanted the full engineering suit as seen in game, [Throssoli] set off to reproduce the entire RIG down to the illuminated face mask and back mounted spine-like health and stasis indicators.  All it really needs are lead weights in the boots to give it that signature stompy Isaac feel. The build incorporates a lot of techniques we typically see in other game related prop builds, such as the black-washing and weathering effects seen in the wheatley puppet and mold making as seen in this Portal Turret build and even daft punk helmets. Keep in mind [Throssoli] is no stranger to prop or suit building, his portfolio of finished projects include halo armor and props, various Star Wars costumes, Mass Effect stuff, a Predator outfit you name it. We could easily loose half a day just perusing all the builds at the site so check it out for yourself!

[via Reddit]

Hackaday Links: October 28th, 2011

October 28, 2011 by 24 Comments

An accidental radial engine

Hack A Day’s very own [Jeremy Cook] was trying to figure out how to push four ‘arms’ out one at a time. What he came up with is a very nice model of a radial engine. Everything was cut on a CNC router and a motor from an air freshener provides the power.

Using a candle to produce light

[Chris] sent in his Candela Amplifier. It’s a Pentium 4 heat sink with a very bright Cree Xlamp LED attached to the base. A bunch of Peltier thermoelectric units are attached to the underside of the heat sink. Put the whole thing on top of a candle, and you can light a room. With a candle. Oh, he’s selling these, by the way.

Objectification and video games?!

We really feel sorry for our lady readers. Guys have so many choices for Halloween costumes, but just about every costume available for women can be reduced to, “Sexy [noun].” Whelp, here’s the Sexy Game Boy, just in time for Halloween. [kazmataz] gets a few bonus points because she went with the DMG-01. It’s better than Sexy Chewbacca, so she’s got that going.

Prototypable 32-bit uCs

[Ng Yong Han] wrote in to tell us about some newish 32-bit PICs that are floating around. The datasheet for the PIC32MX1xx/2xx chips is pretty interesting – USB support and an audio and graphics interface. Oh, they come in PDIPs for ease of prototyping as well. We haven’t seen much from the PIC microcontroller faction recently (Atmel is winning the holy war, it seems). Anybody feel like building something with these?

Makerbot dual extruder


[Lomo] at TU-Berlin is taking a class in rapid prototyping. He built a second print head for his department’s Makerbot Cupcake with a few other students. The result are pretty impressive, although from what we’ve seen, it’s generating the G-code that’s a pain in the butt.