Hack a Day

Centuries ago, craftsmen and smiths of all sort spent hundreds of hours crafting a crossbow. From the fine craftsmanship that went into making the bow to the impeccable smithing a windlass requires, a lot of effort went into building a machine of war. Since [Chris] has a 3D printer, he figured he could do just as well as these long-dead craftsmen and fabricate a crossbow in under a day.

What’s really interesting about [Chris]‘ crossbow is that it is only a single piece of plastic. The bow is integrated into the stock, and the trigger works by some creative CAD design that takes advantage of the bendability of plastic. The only thing required to shoot a bolt from this crossbow is a piece of string. That, and a few chopsticks.

He won’t be taking part in any sieges, but [Chris]‘ weapon is more than capable of shooting a bolt across a room or launching a balsa wood airplane. You can see an example of this after the break.

Filed under: 3d Printer hacks, weapons hacks

[Todd Harrison] wrote in not with a project but with a video tour of his local hackerspace: HeatSync Labs in Mesa, Arizona. He took a camera along with him over the weekend to record what you can expect when visiting the space. You’ll find the tour embedded after the break.

It starts off with something we love to see. The space is being used for a talk and it looks to be quite well attended. The building is one unit in a string of storefronts and this provides a big open space as soon as you walk in the door. Just past this gathering area there are a few rows of electronics work benches which include hardware like bench supplies and scopes, as well as soldering and rework areas. In the back corner they’ve got a great big laser cutter and [Todd] spends some time with one of the members looking through all the fun stuff they’ve made with it. The back room keeps the messy projects like wood working, machine tools, and welding separate from the rest.

The place is remarkably clean and we’ll organized. Make sure you stop by and check it out for yourself if you’re in the area.

This is the second time we’ve seen HeatSync Labs. The first tour was hosted by our own [Caleb Craft]

Filed under: Hackerspaces

The popularization of FPGAs for the hobbyist market means a lot more than custom LED controllers and clones of classic computer systems. FPGAs are also a great tool to experiment with computer architecture, creating new, weird, CPUs that don’t abide by the conventions the industry has used for 40 years. [Victor] is designing a new CPU that challenges the conventions of how to access different memory locations, and in the process even came up with a bit of example code that runs on an ARM microcontroller.

Most of the time, the machine code running on your desktop or laptop isn’t that interesting; it’s just long strings of instructions to be processed linearly. The magic of a computer comes through comparisons, an if statement or a jump in code, where the CPU can run one of two pieces of code, depending on a value in a register. There is the problem of reach, though: if a piece of code makes a direct call to another piece of code, the address of the new code must fit within an instruction. On an ARM processor, only 24 bits are available to encode the address, meaning a jump in code can only go 16 MB on either side of its call. Going any further requires more instructions, and the performance hit that comes along with that.

[Victor] decided a solution to this problem would be to create a bit of circuitry that would be a sliding window to store address locations. Instead of storing the literal address for jumps in code, every branch in the code is stored as a location relative to whatever is in the program counter. The result is an easy way to JMP to code very far away in memory, with less of a performance hit.

There’s an implementation for this sliding window token thing [Victor] whipped up for NXP’s ARM Cortex M3 microprocessor, and he’ll be working on an implementation of this concept in a new CPU over on his git.

Filed under: hardware

[Rodney Lederer] and his cat were bored after moving to a new city. He fixed that for both of them by taking on this project which turns a Wowwee robot into feline entertainment.

It’s no secret that cats have a weakness for the little red dot produced by a laser pointer. [Rodney] put that trait to work by automating the movement of a red laser pointer. After mounting it on a servo motor he got down to work programming an Arduino to move it in a playful manner. But it wouldn’t have been much fun if the this was only capable of preprogrammed patterns, so he also included an IR proximity sensor to help give the thing interactivity. Add to that the treaded robot base and you’ve got mobile cat entertainment. The proof is in the video after the break… the cat is certainly having fun chasing the dot. [Rodney] plans to work a bit more on his code so that the motions of the laser dot include a lot of different patterns to keep things exciting.

Filed under: arduino hacks, robots hacks

Beta fish are one of the easiest pets to care for. So when [Derek] gave his girlfriend one for Valentine’s day he thought the job was done. Turns out these tropical pets want 75-80 F water and that’s not going to happen in a plain old bowl when you keep your home thermostat in the mid sixties during the winter. While looking for a simple heating solution he stumbled across the idea of using a cheap drip coffee maker as an aquarium.

The two main components are already in place: a clear glass vessel for the water and a way to heat it. The real trick is to use the heating element to gently warm the water to the appropriate temperature. Perhaps the key piece of the project is that the device already had a timer that shut off the heating element. This translates to easy control with his MSP430 microcontroller as it means there’s a relay present. He also patched into the two seven-segment displays to give him feedback on the temperature currently being read by the RL1003 thermistor which is submerged in the water. You’ll also note that he added a few LEDs to the lid to give the aquarium some inner glow.

Filed under: cooking hacks, home hacks

We get a ton of tips about weather balloon launches taking hobby electronics into space. But every once in a while one of them stands out from the rest. This project does send an electronic payload into space, but it also lets [David] fly his hardware back from near-space using an RC airplane.

The return vehicle is unpowered, but that shouldn’t be a problem as launching from a weather balloon will provide plenty of altitude for the flight. Because the temperature experienced in that part of the atmosphere is so cold [David] had to take several things into account. Obviously you want your batteries and control electronics to be insulated from the cold. But something that doesn’t usually pop into mind are issues with the servo motors which run the glider’s flaps. They usually have some white grease on the gears. At temps as low as -50C that grease will harden and make the servo stop working so he made sure to clean the gears thoroughly before the flight.

Unfortunately [David] had several problems capturing images and recorded video from the ground station. But his write up is still a fun read and the clip after the break gives a general overview of the entire project from the nose camera of the glider.

[Thanks Limpkin]

Filed under: toy hacks, video hacks

We’ve said our peace over Makerbot and their interpretation of what Open Source means, but the fact remains if you’re sourcing a 3D printer for a high school shop class or a hackerspace, you really can’t do much better than a Makerbot Replicator. Apparently Makerbot is looking to expand their 3D design and fabrication portfolio; they just announced an upcoming 3D scanner at SXSW. It’s called the Makerbot Digitizer, and it takes real, 3D objects and turns them into CAD files.

Since Makerbot and [Bre Pettis] didn’t give out much information about the 3D scanner they’re working on, the best information comes from Techcrunch. The Makerbot Digitizer uses two lasers to scan real objects and turns them into 3D CAD files. The hardware isn’t finalized, and the prototype is made of a few pieces of laser cut plywood. No details are available on how much the Digitizer will cost, when it will be available, or what its resolution is.

Of course 3D scanning of real objects to translate them into CAD files is nothing new for Hackaday readers. We’ve seen our fair share of desktop 3D scanners, including one that was built in a day out of junk. Even the Kickstarter crew has gotten into the action with a few desktop 3D scanners, some of which scan in full color.

Filed under: 3d Printer hacks, news

Ah, PIC vs. AVR, the never-ending battle of electronic design supremacy. Some people swear by Atmel’s AVR microcontrollers, while others are wrong. [majenko] is firmly planted in Microchip’s PIC camp, so he wrote up a nice comparison of Atmel’s AVR versus Microchip’s PIC family of microcontrollers. The results aren’t that surprising; PIC microcontrollers come out as a better product that no hobbyist uses because no hobbyist uses them.

Atmel and their series of AVR microcontrollers has seen a huge increase in popularity in the hobbyist market in the last few years, no doubt thanks to the Arduino and other AVR-powered dev boards. This isn’t to say Microchip and PIC haven’t seen their time in the lime light; there was a time when you could actually buy electronic components at Radio Shack, including kits containing Microchip’s very popular but somewhat outdated Basic Stamp.

After going over the capabilities of the Atmel AVR ATMega328p, the similarly equipped Microchip’s PIC PIC18F25K80, and TI’s MSP430G2533, [majenko] found the perennial favorite, the AVR, lacked in some very important categories. The AVR has a lower resolution ADC, fewer PWM pins, fewer 16-bit timers, while costing about $0.75 more.

Of course [majenko]‘s analysis doesn’t take into account the intangibles of choosing a PIC over an AVR. Thanks to the Arduino’s adoption of the AVR, there are many, many more code and schematic examples floating around on the Internet for just about every project imaginable. The development tools for PIC are a bit more expensive than their AVR equivalents; A PICkit2 runs about $50 while AVR ISP programmers can be found just about everywhere for pocket change.

It’s a lazy Sunday, so all ‘yall can go on and argue in the comments.

Filed under: Microcontrollers

With daylight savings time starting up, you might not have quite as much need for lighting, but this pair of hacks should keep everything well lit whether outside or indoors.  Check out the videos of both in action after the break.

The first lighting solution comes to us from [Ben]‘s Youtube channel. It’s a simple solution, press-fitting a clamp light into a 1 inch PVC Tee to attach the light to a pipe. The base is made with PVC shaped into three feet for a (hopefully) sturdy rest.  Several lights can be used as needed, and would probably work well for making his next video.

The second light also comes to us from Youtube, and is about converting a stock LED light into one that is much brighter. Skip to around 7:00 to see the outdoor comparison.  You may or may not want to do this exact hack, but you never know when you might want to swap out your blinkenlights for something that will scare the neighbors!

 

Filed under: led hacks

This is [Paul Mandel's] Ground-truth velocity sensor. That’s a fancy name for a device which tracks the movement of a vehicle by actually monitoring the ground its travelling over. This differs from simply measuring wheel rotation (which is how traditional odometers work) in that those systems are an indirect measurement of motion. For us the interesting part is the use of an ADNS-3080 single-chip optical mouse sensor on the left. It’s cheap, accurate, and only needs to be ruggedized before being strapped to the bottom of a car.

[Paul] designed a case that would protect the electronics and allow the sensor to mount on the uneven underbelly of a vehicle. The optical chip needs to be paired with a lens, and he went with one that cost about ten times as much as the sensor. Data is fed from the sensor to the main system controller using the PIC 18F2221. One little nugget that we learned from this project is to poll a register that always returns a default value as a sanity check. If you don’t get the expected value back it signals a communications problem, an important test for hardware going into the vibration-hell that is automotive technology.

Filed under: parts, transportation hacks

When the truck rolls up, everything seems normal enough. It’s a generic oil tanker. But when the theme from “2001: A Space Odyssey” begins to play and the side of the tank starts to open, you suddenly realize things are not what they seem. This is no mere tanker truck, it’s a massive meat cooking monster dubbed the “X Grill”.

[Ken Foster], owner and creator of this $40K+ beast, worked with welder [Gary Webb] to custom design and fabricate every component of the vehicle, from hinges to hydraulic systems. They claim not a single part came from a box. The cooking area, complete with speakers and spotlights, has storage cabinets, stainless steel prep counters, a four burner stove, and a 42 inch grill. If that’s not enough, there are three more grills you can set up beside the truck and hook into the system. All the appliances are run off a 65 gallon propane tank that’s mounted to the side of the truck.

Although the “X Grill” is available to rent for private parties, [Ken] says they spend most of their time at community and charitable events. He donates his equipment and cooking services, and the host group supplies the food and gets to keep any profit.

Good work guys!

[via Neatorama]

Filed under: cooking hacks, transportation hacks

We would wager that most of the home etched PCB projects we see around here use the toner transfer method. But the next most popular technique is to use photosensitive ink which resists the etching acid once it has been exposed to light. Most people buy what are called pre-sensitized boards, but you can also get ink to make your own. [Jardirx] does this, and uses an old hard drive to apply an even layer of the light-sensitive ink.

The narration and subtitles of the video found after the break are both in Portuguese, but it’s not hard to figure out what’s going on here. He begins by using double-sided foam tape to secure the piece of copper clad board to the hard drive platters. You’ll want to center it as best as you can to keep the vibrations to a minimum. From there [Jardirx] applies a coating of the ink using a brush. The image above is what results. So as not to get ink everywhere, he then lowers a soda bottle with the bottom cut off to catch the excess. Power up the drive for a few seconds and the board will have a nice even layer ready for a trip through a UV exposure box.

[Thanks Daniel]

Filed under: tool hacks

Every year, [Nathan] hosts an Oscar party with a lot of drinking, adoring the off-color comments of [Joan Rivers] and some low stakes wagering. Everyone throws a dollar into the pot for a particular award, and when the winner is announced, [Nathan] splits the pot between the winners and begins counting out coins. As convenience stores have discovered, there’s an easier way to dole out pocket change, so this year [Nathan] created a change machine that dispenses coins for the winners.

The change machine is just like the ones you would find at a supermarket or convenience store; load up the machine with a few rolls of coins, and a few solenoids fire in response to serial data received from a computer. [Nathan] used an Arduino, Serial shield, button matrix, and LCD display for his change machine interface, allowing him to dispense pocket change to each of the winners after an award is announced.

Filed under: arduino hacks

Touch screens are nice — we still can’t live without a keyboard but they suffice when on the go. But it is becoming obvious that the end goal with user interface techniques is to completely remove the need to touch a piece of hardware in order to interact with it. One avenue for this goal is the use of voice commands via software like Siri, but another is the use of 3D processing hardware like Kinect or Leap Motion. This project uses the latter to control the image shown on the 3D display.

[Robbie Tilton] generated a 3D image using Three.js, a JavaScript 3D library. The images are made to appear as if floating in air using a pyramid of acrylic which reflects the light toward the viewer’s eyes without blocking out ambient light in the room. In the past we’ve referred to this as a volumetric display. But [Robbie] points out that this actually uses the illusion called Pepper’s Ghost. It’s not really volumetric because the depth is merely an illusion. Moving your point of view won’t change your perspective unless you go around the corner to the next piece of acrylic. But it’s still a nice effect. See for yourself in the demo after the jump.

[via Dvice]

Filed under: video hacks

Who has an airport carry-on X-ray machine sitting in their garage? Apparently [Mike] does, and he’s sharing the fun by posting a video teardown series that really digs into the machine’s hardware and operating system.

At this point the series includes six lengthy segments. The first episode, which you’ll find embedded after the break, starts with an external overview of the hardware. [Mike] mentions that it’s not functional at that point. He guesses that this has to do either with security settings to enable the machine (it does produce x-ray after all) or corrupt memory in an EPROM chip. The password lockout is later confirmed when he looks at a code disassembly and finds strings requesting username and password to gain access to some of the menus. The second installment involves more disassembly to figure out the passwords and gain full access to the machine. By the fourth video he’s X-raying random items from around the shop and then some.

It’s a lot to watch, but it’s exciting to see how far he gets with the rare equipment.

[Thanks Andrew]

Filed under: teardown

This is [Wpqrek's] Commodore 64 modified to go on the road with him. The elderly machine has a special place in his heart as it was what he learned to code on. He performed a series of hacks which house everything necessary to use the machine inside the original case.

Obviously the hack that has the most effect when it comes to portability was swapping a display for the small LCD mounted above the number keys. This was a pretty simple process because the screen, originally intended for a rear view camera in a vehicle, already had a composite video input. To emulate the floppy disc drive he’s using an SD card via an sd2iec board which he laid out himself. Rounding up the alterations is a stereo SID. The second channel uses the pre-amp circuit cut from a second C64. This audio hardware will let him do cool things like playing some classic Zeppelin.

You can get a video tour of these alterations after the break.

Filed under: classic hacks

A 2:1 gear reduction slows down a spinning shaft to half speed and doubles the torque. Repeat this a few times, and you’ve got a ludicrous amount of torque moving too slowly to see with even precision instruments. That’s the idea behind [Jeshua]‘s project, a Printed Machine partially embedded in a block of concrete.

[Jeshua]‘s build is a replica of one of [Arthur Ganson]‘s kinetic sculptures. [Ganson]‘s machine uses 50 sets of gears to reduce the rotation of 200 RPM motor more that 200  quintillion times. The final gear in the sculpture is embedded in a block of concrete, waiting to be freed by either erosion of the concrete block or the sun going nova.

Instead of metal gears, [Jeshua] used 3D printed gears in PLA. After assembling them on a stand, he cast concrete around the final, barely moving gear. It’s an impressively useless build that will turn to dust before the final gear makes even 1/10th of a revolution. This machine could have a longer life if it were printed with ABS instead of PLA, but with the time scales we’re talking about here it won’t make much difference.

Filed under: classic hacks

Cheap GPS modules

If you’re making a GPS-enabled project, you may have noticed the commonly available GPS modules are pretty expensive – usually around $50. Here’s one for $8. It’s a U-blox PCI-5S GPS receiver on a PCI Express card. There are test points for serial and USB data, though, so fitting this in your project is a breeze.

Grandfather clock makes a giraffe’s scarf

Here’s a clock project from [Siren Elise Wilhelmsen]. Over the course of 365 days, the clock knits a giant, 2-meter tube of yarn that should be the perfect start for a half-dozen pairs of socks. No video for this, but if you find one, post a comment.

A huge hackerspace for Hotlanta

Atlanta is getting a new hackerspace. It’s called My Inventor Club and they’re starting to move into their space. Judging from [Scott]‘s pictures of the new space it’s huge. We can’t wait for the video tour once they’re done moving in.

Ardino and Windows 8

Windows 8 is… weird… and you can’t install unsigned drivers without a lot of rigamarole. This means installing the Arduino IDE is a pain but [Dany] has a solution. Reboot into “test mode” and you can install unsigned drivers without your computer throwing a hissy fit.

Tweet for welts and bruises

[Zach]‘s boss told him to come up with a Twitter-controlled paintball gun. Why he was asked to build this is beyond us, but the build is still cool. It’s powered by an Arduino and was built in just 12 hours. If only there was a video stream…

Hey guys, need some help here.

Alright, I’ve got a little problem with component sourcing. I’m making a ‘shield’ for the Raspberry Pi. Does anyone know where I can get really long female headers for the GPIO pins so the board will fit over the USB and Ethernet jacks? Here’s the project if you’re curious. I think the female part of the header needs to be 14mm high at least to fit over the USB port.

Filed under: Hackaday links

Here’s an interesting build that combines light, sound, and gesture recognition to make a 360 degree environment of light and sound. It’s called The Bit Dome, and while the pictures and video are very cool, we’re sure it’s more impressive in real life.

The dome is constructed of over a hundred triangles made of foam insulation sheet, resulting in a structure that is 10 feet in diameter and seven and a half feet tall. Every corner of these panels has an RGB LED driven by a Rainboduino, which is in turn controlled by a computer hooked up to a Kinect.

The process of interacting with the dome begins by stepping inside and activating the calibration process. By having the user point their arms at different points inside the dome, the computer can reliably tell where the user is pointing, and respond when the user cycles through the dome’s functions.

There are bunch of things this dome can do, such as allowing the user to conduct an audio-visual light show, run a meditation program, or even play Snake and Pac-Man. You can check out these games and more in the videos after the break.

Filed under: Kinect hacks, led hacks

[Hamster] admits this 1080p HDMI hack for an FPGA doesn’t put a signal that’s fully up to specifications. But as you can see in the image above it does output a 1920×1080 image at 60 Hz, which is the size and frequency of full HD video. It falls just short due to some jitter, which may be just fine if this is only being used for early prototyping and will be replaced with a dedicated encoder later in the design process.

Here he’s chosen a Pipistrello board but thinks that any device which has a Spartan 6 chip with the differential pairs connected to an HDMI socket will work. The difficulty of the task comes in serializing four output channels at 1500 Mb/s each. Because of this just coding your logic isn’t going to work. After roughing out the design [Hamster] went back in and chose to manually place some of the components to ensure that data from each channel arrives at the same time.

While you’re messing with HDMI you may also want to give this overlay hack a try.

Filed under: video hacks