Hack a Day

Whether you call it enhanced interrogation or torture, the subject is a lot less serious when the victim is a sugary confection. The LVL1 Hackerspace in Louisville, Kentucky recently held an event focused on getting Peeps — the bunny-shaped sugar-covered marshmallow treats — to spill their guts. Participants developed a range of tongue-in-cheek torture devices then demonstrated their functionality on the bunnies.

You shouldn’t be surprised that the event posting starts with Peep waterboarding. But from there the rigs do get a lot more creative. For instance, the electric chair above connects the bunny to a stun gun (there’s no mention of what that big set of capacitors has to do with this. There’s also an Iron Maiden which is really more of a Plastic Maiden. It subjects the marshmallow to multiple stab woulds using a plastic egg as an enclosure and a hair brush head as the spikes. You can’t mutilate Peeps without at least one being sent through a microwave. But perhaps our favorite is The Rack. A pair of them were built, one was laser cut and the other was constructed free-hand. Both are a whimsical take on a historically brutal implement.

Recently there were a bunch of videos going around the net about some of the greatest pickpockets in the world. Simply put, if they wanted something you had, they were going to take it and you probably wouldn’t notice. I’ve always kept my wallet in my front pocket, and usually with my hand on it, but they even showed them getting around that in the video (you can’t always be vigilant).

I had the idea to make some kind of alarm that would go off if anyone but me removed the wallet from my pocket. A quick google search revealed tons of wallet alarms, but I noticed that they all had a credit card form factor(that’s good) and would make noise when exposed to light(that’s bad). This represents a problem since the pickpockets in the videos tended not to open the wallets till later at another location. I needed something that would make noise as it was removed from my pocket. Most importantly, I needed the alarm to be located inside the wallet. This immediately makes the wallet undesirable and will hopefully make someone drop it like hot coals.

I happened to have a few little magnetic window alarms sitting around. They’re just a loud buzzer with a magnetic reed switch.  After holding one up to my poor fat old neglected wallet, I saw that the alarm was roughly the same thickness as all the old business cards I should’ve cleaned out of my wallet anyway.

I promptly tore the alarm apart and started planning how I was going to slim it down as much as possible.  Most of the thickness is from the case, the batteries would be the next biggest contributor.  After destroying the buzzer from one by trying to pry it from its plastic enclosure, I decided to leave the buzzer and simply live with the thickness. After all, if the prototype worked well, I could design something in a credit card form factor later. That is, if my attention span were long enough to do a thing like that.

The only real modification I made to the alarm itself was to un solder the reed switch and relocate it to the very end of the whole mess. This would allow it to be at the “spine” of the wallet and keep the power switch at the opening for easy access. The rest was simply cutting away as much bulk as possible and hot gluing things together.

It actually works exactly as expected. There are two choices for the alarm, a single chime when removed, or a constant alarm. The only big upgrade that I would suggest would be a stronger magnet so it wouldn’t need to be aligned perfectly.

Children of the information age are doomed to have the worst handwriting just for lack of use if nothing more. But some students at Olin College harnessed technology to find a solution to that problem. Meet Herald, a CNC machine that can produce beautiful calligraphy.

The machine uses a gantry to move the writing tip along the X and Y axes. The flexible-nib calligraphy pen is mounted on a sprocket which rotates the tip onto the writing surface, taking care of the third axis. The rig was beautifully rendered from their CAD drawings, then tweaked to ensure the smoothest motion possible before the quintet of Sophomores began the physical build.

The drive hardware is very simple yet it produces great results. It uses an Arduino along with three stepper motor drivers. There are also limiting switches to protect the hardware from runaway code. The software interface designed by the team lets the user cut and paste their text, and select a font, font size, alignment, etc. It then converts the text to G-code and pushes it to the Arduino where the GRBL package takes care of business.

Don’t miss the device in action, writing out a [Langston Hughes] work in the clip after the break.

Power outage? For the average citizen it’s very easy to take electricity for granted. Go a few hours or more without it though, and you’ll suddenly be reminded just what a luxury it is. During an emergency situation, sometimes you have to come up with alternative methods to get the job done. This human powered cell phone charger is a great example.

Using just a few ordinary around the house items, [The King of Random] turned a cordless electric drill into a human powered electrical generator. If the drill is run in reverse and cranked by hand, the generated energy can be transferred through the battery terminals to a connected device.  So, he cut a USB charger cable in half and wired it up to the terminals to be able to charge his cell phone. Some yarn, a salad fork, a mixing beater, a scrap 2″x4″, some aluminum foil, and scotch tape were the only other materials he used. Using this technique, a totally dead phone battery was charged in around 3 hours.

Remember that this method is only intended to be used in an emergency, not as every day practice. Using these methods could potentially overheat or damage your gear, so be careful.

Check out the MacGyver worthy video tutorial after the break.
[via Neatorama]

We know exactly what [Dan] is going through. We also bought a cheap wireless doorbell and are plagued by the batteries running down. When that happens, the only way you know is when people start pounding on the door because you’re not answering the bell. Well no more for [Dan]. He built a backup system which monitors the voltage of the batteries on the chime unit.

You can see the small bit of protoboard he used to house the microcontroller and the UI. It’s an ATtiny13 along with a green LED and a single push button. The idea is to use the chip’s ADC to monitor the voltage level of the pair of batteries which power the chime. When it drops below 3V the green LED will come on.

First off, we wish these things would come with better power supply circuits. For instance, we just replaced the CR2032 in an Apple TV remote and measured the voltage at 2.7V. That remote and the chime both run from a 3V source. Can’t they be made to work down to 1.8V? But we digress.

In addition to monitoring voltage [Dan's] rig also counts the number of times the chime has rung. Every eight seconds it flashes the count in binary, unless he presses the red button to clear the count. This is shown in the video after the break. We guess he wants to know how many times this thing can be used before running the batteries down.

Seriously though, for a rarely used item like this how hard would it be to use ambient light harvesting to help save the batteries? Looking at some indoor solar harvesting numbers shows it might be impossible to only power this from PV, but what if there was a super-cap which would be topped off with a trickle from the panels but would still use the batteries when that runs down?

“I don’t understand, you don’t have the technology.” OK, so it’s not actually a futuristic tool with the same capabilities as the one off the hit TV series Dr. Who, but this homemade “sonic screwdriver” is a multifunction device that’s pretty cool nonetheless.

Created around an Arduino Pro Mini, [Gunther] really one-upped the last screwdriver we featured. Built in functions include: brown note tone generator, dog whistle, EMF meter, flashlight, IR universal remote, laser pointer, ohm meter, sound level meter, voltage detector, and a voltage meter.  You can also have an electromagnet or output voltage supply if you want. If that wasn’t enough, it can even play the theme song from Star Wars! Whew. That’s a mouthful of functionality.

Although he has posted the Arduino code, you’ll have to keep an eye on his site for more details if you want to create your own. He’s mentioned that he’s working on blue prints and a full parts list… Awesome. Now where’s that lock pick function?

Check out a video showing off some of the features after the break.

[via Make]

SMD components may be a little challenging for the home builder – even though the’re inordinately practical for homebrew PCBs – but if you play around with electronics and solder long enough, you’re eventually going to run into the horrors of BGA parts. Instead of convenient pins, BGA parts have tiny metallic balls on which solder is applied, a board is thrown through a reflow oven, and hopefully at the end, everything works. Sometimes these balls corrode or otherwise need to be reflowed. This isn’t an easy process, so [Edmar] came up with his own BGA rework station that costs much less than commercial offerings.

[Edmar]‘s build began when he wanted to repair a graphics card. A common error on his Amilo XI2428 graphics card is having the small balls on the underside of the chip corrode, leaving the user with a non-functional graphics card. Towel trick notwithstanding, the easiest way to fix this error is to heat up the card to above the melting point of solder, removing the chip, and resoldering it with careful application of solder paste.

[Edmar]‘s reflow station is made of an electric skillet for the bottom of the board, an infrared lamp for the top side of the board, and control circuitry constructed from an ATMega128, temperature sensors, and a huge power supply. The temperature is controlled via USB by a computer, allowing [Edmar] to set a temperature profile as recommended by the BGA chip’s data sheet.

Right now, removing a BGA chip works great, but [Edmar] is still working on the tech necessary to replace a BGA chip on a board.

This project most certainly has some of Trailer Park Boys rolled into it. We say that because the living room is the only place this will ever been used and this guy’s reaction to getting shocked is exactly how [Ricky] would respond.

The sword on the left has an electronic stun mechanism built into it. it works by energizing two blades which are separated by nylon bolts and spacers. Look closely at the tip and you’ll see the blue glow which indicates high voltage. To shock your victim you have to touch them with both blades at the same time. This is demonstrated in one of the videos after the break. But the real pain comes when [Jonathan] — the guy who built the stun sword — touches it on either side with this pair of blades. His body completes the connection and his NSFW language tells the tale of how it feels.

This thing seems to pack a bit more of a punch than our own stun-gun enabled quadcopter.

Hardware description:

Shock tests:

[Thanks Rush]

They’re edible, yes. But they don’t light up. That’s fine with us, since the process [Becky Stern] used to make these gummy candy LEDs taps into several techniques handy to have under your belt.

The first part shown in her video (embedded after the jump) is to make a mold for the candies. You probably have a few bags of LEDs in your parts bin. Those along with a trough made of foam core come together to create the form for the silicone mold. After mixing, pouring, and hardening, [Becky] peels the silicone off of the LEDs and sends it through the oven to make it food-safe. Mixing up the candy uses simple ingredients (gelatin, water, and ascorbic acid) but you’ll need to follow the methodology closely to get the taste and clarity you’re used to. Syringes are used to fill the tiny voids in the mold before adding leads which were 3D printed using PLA.

These will be a huge hit at your next hackerspace meeting!

[Photo: Johngineer]

Those of us that run Linux on a modern or nearly-modern PC know that it’s a capable operating system.  It’s also (at least in my case with Ubuntu) extremely easy to install on a semi-modern computer. On a mid-90s era PowerMac 7200, things aren’t quite so simple.

In a testament to both his technical ability, and possibly even more so his tenacity, [Chris] was able to get Debian 6.07 running on a PowerMac destined for destruction. He had slated a few hours to upgrade this 56 Megabyte monster, but it turned out to be a several-day event. Those that are well-schooled in Linux may find the hairy details useful, and some more background can be found in part one. This project was a stepping-stone to something else, so we’re anxious to see what the end result is.

If you find this interesting, feel free to check out the retro edition of our site. It’s not entirely about ancient computers, but it can hopefully be displayed on one.

via [twitter]

Ahhh space. The final frontier. While many people dream of one day becoming an astronaut (and possibly battling aliens or cylons), it’s a select few who actually make it their reality. Fortunately for us, there’s a middle ground that allows the masses to still have some fun in the sky. Enter the “Pongsat” program – space experiments within a ping pong ball.

Created by JP Aerospace, this free program allows anyone to create their own mini experiment and send it off to the edge of space. The imagination is the limit. Curious if a marshmallow will expand? Interested what the temperature would be? Wonder if you can charge a solar battery? Stuff it inside a ping pong ball and find out!

Check out the PDF Users Guide to get started, then their Blog and Facebook page for more up to date information.  Now go out there and get your experiment to Mars! (Or at least 100,00 feet)

Watch a video of in flight footage after the break.

[via adafruit]

[Brian] has brought together a powerful collection of hardware to build a robot. The end goal is to have a robot that’s controlled by a Wiimote.

The Wiimote communicates over Bluetooth with a Raspberry Pi, which is running a Python script. This script uses the CWiid Python module to communicate with the controller, and [Brian] has detailed instructions on getting the Wiimote working with a RPi. The RPi controls an ATmega based development board over SPI, which drives an h-bridge to control the two DC motors that move the robot.

[Brian]‘s code for this could be helpful for anyone looking to control their RPi with a Wiimote. Since Wiimotes and Bluetooth dongles are fairly cheap nowadays, this is a great way to drop in wireless control to any RPi project, or even to control your media center from the couch.

After the break, check out a video of the build in action

This innocent looking Maglite houses a piston and barrel, making it into a functional pneumatic BB gun. A Maglite was chosen due to its high durability, and easy access to the internals. A schrader valve sticks out of the battery cap, which allows the gun to be charged using a standard fitting. A brass tube is used as the barrel, and a piston controls firing.

Firing the gun is simple. First, the whole thing is charged up to the desired pressure. Then the ammunition is inserted into the barrel. At this point, the rubber piston is held against the end of the barrel by the pressure in the gun. By pushing the pin of the valve in, the piston is able to move back slightly. This acts as the trigger, and causes air to rush into the barrel, firing the BB.

The results are fairly impressive. Using a chronograph, the speed of the BB was measured at 850 feet per second. Using the Gas Gun Design Tool simulator, it was estimated that the gun could fire at over 1000 feet per second, and maybe even break the sound barrier.

If you want to check your house for hot air leaks, take pictures of the heat coming off a rack of equipment, or just chase the most dangerous animal, [Arnie], through the jungles of central america, a thermal imaging camera is your friend. These devices normally cost a few thousand dollars, but the team behind the Mu Thermal Camera managed to get the price down to about $300.

The basic idea behind the Mu Thermal Camera is overlaying the output of an infrared thermopile – basically, an infrared camera – on top of the video feed of a smart phone’s camera. This is an approach we’ve seen before and something that has even been turned into a successful Kickstarter. These previous incarnations suffered from terrible resolution, though; just 16×4 pixels for the infrared camera. The Mu thermal camera, on the other hand, has 160×120 pixels of resolution. That’s the same resolution as this $2500 Fluke IR camera. After the indiegogo campaign is over, the Mu camera will eventually sell for $325.

We have no idea how the folks behind the Mu camera were able to create a thermal imaging with such exceptional resolution at this price point. The good news is the team will be open sourcing the Mu camera after their indiegogo run is over. W’e'd love to see those docs now, if only to figure out how a thousand dollars of infrared sensor is crammed into a $300 device.

We’ve seen our share of replica props, but [Nathan]‘s replica of the spy’s sidearm from Team Fortress 2 is the bee’s knees.

The build began as an off-the-shelf Airsoft gun. After removing the barrel and cylinder, [Nathan] used Apoxie Sculpt and a whole lot of sanding to turn a stock piece of metal and plastic into something that came straight from the Mann Co. store. The in-game version of the Ambassador also includes an engraving of the object of the spy’s affection, replicated by [Nathan] with some very careful Dremel work. Once the prop was done, [Nathan] built a mold box out of plywood and filled it with silicone rubber. This allowed him to make several castings of his prop weapon

This isn’t [Nathan]‘s only TF2 replica prop; he also made a replica of the stock sniper gun and scout’s scattergun and a megaphone from Borderlands. In an effort to out do himself, [Nathan] is gearing to build a gun that fires two hundred-dollar, custom-tooled cartridges at ten thousand rounds per minute. He has yet to craft any hats.

This thing is so cool it almost looks fake. But [Matt Richardson] isn’t a hoaxster. He actually built what might be called a heads-down display for your bicycle. He refers to it as a headlight because it borrows a similar function. It mounts on the handlebars and shoots light off the front of the bike. But it’s more than just a battery and a bulb, this uses a pico-projector to give that light some meaning. In the video after the break he shows it off on the streets of NYC.

So far he’s only displaying information that has to do with the speed of travel, but the proof is there just waiting for a brilliant new use. Feeding the projector is a Raspberry Pi board. For this prototype [Matt] mounted it, along with the portable cellphone charger which plays the role of the power source, on a hunk of hardboard strapped inside the bike frame.

If you’re thinking of doing this one yourself beware of the BOM price tag. That projector he’s using runs upwards of $400. We wonder if you could hack together a rudimentary replacement with an old cellphone screen and this diy film projector?

This little device lets you play some head-to-head pong using a spinning LED display. We’re really in love with the design. You get a pretty good idea of the Persistence of Vision aspect of the build by looking at this picture. But hearing [Dennis] explain the entire design in the video after the break has us really loving its features.

He’s using the head from a VCR as the spinning motor. The display itself uses a vertical row of LEDs with a bit of wax paper as a diffuser. These are current limited by a 1k resistor for each of the eight pixels. They’re driven by a PIC 16F690 but you may have already noticed that there’s no battery on the spinning part of the board. It gets voltage and ground from a pair of brushes which he fabricated himself. To avoid having to do the same thing to map the control buttons in the base to the spinning board he came up with something special. There’s a downward facing phototransisor which registers LED signals from the base to move the paddles up or down.

If you love this project check out the POV Death Star.

[Christopher] is really going the distance with his liquid-filled 3D printed lens project. The idea is to create a bladder out of two pieces of clear plastic. It can then be filled with liquid at a variable level of pressure to curve the plastic and create an adjustable lens. He was inspired by the TED talk (which we swear we already covered but couldn’t find the post) given by [Josh Silver] on adjustable eyeglass lenses.

Don’t miss the video after the break. [Christopher] shows off the assembly process for one lens. Two 3D printed frames are pressure fit together to hold one piece of plastic wrap. Two of those assemblies are then joined with JB weld and some 3D printed clips that help to hold it. A piece of shrink tubing is used as a hose to connect a syringe to the bladder. By filling the lens assembly with water he’s able to adjust how it refracts light.

[Rachel Levine] was one of the mechanical engineers on the team at the Rochester Institute of Technology who built this resin-based 3D printer. She wrote in to show off the fantastic work they’ve been doing. Their project website is daunting to take in at first, which shouldn’t be all that surprising since the concepts used here are fairly advanced. But give yourself a few minutes of blind clicking and you’ll begin to grasp the scope of this fantastic piece of engineering. The bad news is you’re not going to whip the thing together in a weekend. The good news is that if you’re determined to build one this should give you the lion’s share of the background you’ll need to make it happen.

The rig pulls a printed object up from the ooze on the build platform. They’re using resin that is cured with visible light. That’s why you see the level in the foreground; the bath needs to be a uniformed thickness so that it solidifies correctly when the light hits it from the underside. The build table is made of glass sandwiched between gaskets where it comes in contact with the frame, keeping the liquid in place while letting the DLP projector shine through. Check out the fast-motion build video after the break to see how each layer is exposed to light, then pulled upward to make room for the next. We estimate the build was around two hours of real-time and you can see that a technician replaces the extracted resin at regular intervals during the process.

DLP Projector based printers have been gaining in popularity. Check out this roundup of several offerings from last year.

This isn’t a thrift-store coffee table modified as a craft project. [Dandujmich] built it from the ground-up using framing lumber, bottle caps, plastic resin, and some electronics for bling.

The first step was to see if he had enough caps on hand for the project. It’s hard to grasp how many were used just by looking at it, but the gallery description tells us there’s about 1700 which went into the design! From there he grabbed some 2x4s and began construction. The table legs started with two end assemblies built by doweling the legs to the end cross pieces. From there he cut a rabbit on the side rails and screwed them to the leg assemblies from the inside.

The tabletop includes a frame with a recessed area deep enough to keep the caps below the surface. After spending about ten hours super gluing all of the caps in place he mixed and poured two gallons of the resin to arrive at a glass-like finish. The final touch is some custom hardware which pulses two rows of embedded LEDs to music being played in the room. The video after the break isn’t fantastic, but it gives you some idea of how that light rig works.

[via Reddit]