Saturday, April 5, 2014 - 04:01Powering a RPi with Hydrogen
Looking for a new way to power your Raspberry Pi? The raspberryHy project aims to develop a small fuel cell designed for powering the credit card sized computer. It adds a proton exchange membrane (PEM) fuel cell, a battery, and custom control electronics to the Pi.
The system takes hydrogen in from a compressed hydrogen cartridge and feeds it through a regulator. This passes the hydrogen into the PEM fuel cell at the correct pressure, and creates a potential. The control electronics boost that voltage up to the 5 V required on the Pi’s USB port. There’s also an electronically controlled purge valve which periodically exhausts the fuel cell.
There’s a few reasons you might want to run your Pi with hydrogen. Run time of the fuel cell is limited only by the amount of hydrogen you can store. In theory, you could connect a large cylinder for very long run times. Combined with a battery, this could be quite useful for running Pis in remote locations, or for long-term backup power. The raspberryHy will be presented at Hannover Fair 2014 this month.
Saturday, April 5, 2014 - 01:01Building an Inductive Loop Vehicle Detector
[Trax] was asked by a friend to build a device that could detect the presence of a car in front of his garage gate for it to open automatically. After searching the web for such a project and trying many of them, he decided to build his own detector based on an induction loop. As you may have guessed, this kind of detector works by detecting an inductance change in a wire loop (aka coil) buried in the road. Having a car pass several inches on top of it produces such an effect.
[Trax]‘s write-up shows a very well thought and professional design. All the detector parameters can be adjusted using DIP switches and buttons: detection type (presence/pulse), signal filtering, main frequency and sensitivity. The wire loop is isolated from the main sensor electronics using a 1:1 isolation transformer and a Colpitts oscillator is used to drive the latter. Moreover, gas discharge tubes are also used for lightning protection.
The change in inductance translates to a change in resonant frequency which is later detected by the main microcontroller. The board is 24V AC powered and a diode bridge + LM2596 SMPS step-down converter are in charge of generating the required +5V in an efficient way.
As if this was not enough, [Trax] also made a PC-based tool that can change other platform settings using a serial connection. All the resources can be downloaded from his website and a few videos are embedded after the break.
Friday, April 4, 2014 - 23:30Sci-Fi Contest: Source Universe Roundup
The Hackaday Sci-Fi contest has 36 entries so far. Since there are fifteen prizes available, you stand an excellent chance of winning; but you can’t win if you don’t play. It’s pretty easy to be considered for the contest. You simply need to hack together something Sci-Fi related and show off your work. Head over to the contest page and check out the details. Ten of the prizes are popularity-based, so posting early is the best bet! For those that were put-off by the team requirement, there’s a hack to get around that.
Since this is a themed contest we thought we’d give you an update on where inspiration is coming from. Below is the break-down of each Sci-Fi universe that has been so-far adopted by the entrants. We’d like to point out that this isn’t limited to movies, as the bulk of inspiration is to be found in literature. Why don’t we get a comment thread going here to help brain-storm for people who want help locking onto an idea?
Oh, and if you’re wondering about the banner images. These were taken from three of the contest projects. The upper left is a GLaDOS replica controlled by Google Glass (complete with Nerf dart gun) inspired by Portal. Bottom left is a pair of Peril-Sensitive sunglasses inspired by A Hitchhiker’s Guide to the Galaxy. And the bottom right is a life-sign scanner inpired by Stargate Atlantis.
- Unknown (genre or misc themes) 9
- A Hitchhicker’s Guide to the Galaxy 4
- Back to the Future 3
- Star Wars 3
- 2001 A Space Odyssey 2
- Doctor Who 2
- Stargate 2
- Thor 2
- Blade Runner 1
- Demolition Man 1
- ET: The Extra Terrestrial 1
- Futurama 1
- Harry Potter 1
- Knight Rider 1
- Portal 1
- Prometheus 1
- Start Trek 1
Filed under: contests
Friday, April 4, 2014 - 22:01Tube Headphones Rock Out While Keeping the Family Peace
It’s hard being a kid sometimes. [Young] likes his music, but his dad is an overnight trucker. With his dad sleeping during the day, [Young] has to keep the volume down to a reasonable level. He could have bought some commercial headphones, but he wanted something a bit more customized. Rather than give up on his tunes, he built a pair of headphones with an internal tube preamp amplifier. [German language link -- Google translate doesn't want to work with this one but Chrome's translate feature works].
Two 1SH24B preamp tubes feed two LM386 amplifier chips, creating a hybrid amplifier. The 1SH24B tubes are designed to work on battery voltage, so a step up circuit wasn’t necessary. However, [Young] still needed to provide an 8 cell battery pack to run his amp. Speakers were a 3 way coaxial of [Young's] own design. He built the headphone frame using candy tins and cups from commercial headphones. A final touch was a window so everyone can see all that vacuum state goodness. Considering that [Young] is only 16, we’re looking for some great things from him in the future.
If you don’t want to strap the tubes to your skull there are other options. But you have to admit it makes for a cool look. Starbucks here we come.
Friday, April 4, 2014 - 19:00We’re At The Vintage Computer Festival This Weekend!
This weekend takes some of the Hackaday crew to the Vintage Computer Festival East in Wall, New Jersey. There’s going to be lots of cool stuff, some dork walking around handing out Hackaday t-shirts and stickers, and more awesome retro computation devices than you can shake several sticks of RAM at.
On the agenda for Friday are a host of talks that include bootstrapping CP/M, assembly programming, disk imaging, and a talk from our very own [Bil Herd] on how to not kill yourself with a CRT monitor.
Saturday is when things really heat up with exhibits including a PDP-8, a 1960s UNIVAC, Chromeco Dazzlers, VAXxen, and a whole slew of computers that weigh less than several hundred pounds. There’s even a real Apple I. Seriously. There are also workshops that include some really obscure work from the late, great [Jef Raskin], and more talks, including [Dave Haynie]‘s recollections of Commodore’s circling the drain.
The VCF is hosted at InfoAge, an exceptionally cool vintage technology treasure trove that’s more than worth the visit, even if there weren’t a vintage computer festival going on this weekend. We caught up with the InfoAge guys a while back, and needless to say, if you come, you’ll have fun.
If you see somebody walking around with a Hackaday t-shirt on, be sure to tell them you’re a fan. If they don’t know what you’re talking about, ask them who they got the shirt from. Regular updates to follow, including a video of someone loading the Hackaday Retro site with an Intel 4004 microprocessor. I didn’t think that was possible either.
Oh, watch our Twitter or something. That’s a thing now.
Friday, April 4, 2014 - 16:01SQL Injection Fools Speed Traps and Clears Your Record
Typical speed camera traps have built-in OCR software that is used to recognize license plates. A clever hacker decided to see if he could defeat the system by using SQL Injection…
The basic premise of this hack is that the hacker has created a simple SQL statement which will hopefully cause the database to delete any record of his license plate. Or so he (she?) hopes. Talk about getting off scot-free!
The reason this works (or could work?) is because while you would think a traffic camera is only taught to recognize the license plate characters, the developers of the third-party image recognition software simply digitize the entire thing — recognizing any and all of the characters present. While it’s certainly clever, we’re pretty sure you’ll still get pulled over and questioned — but at least it’s not as extreme as building a flashbulb array to blind traffic cameras…
What do you guys think? Did it work? This image has been floating around the net for a few years now — if anyone knows the original story let us know!
Filed under: computer hacks
Friday, April 4, 2014 - 13:00Fixing Misaligned PVC With Kerf Bends
Our old pal [Jeremy Cook] is doing his own remix of [Theo Jansen]‘s Strandbeest, and like the original, he’s using PVC pipe. Unlike the originals, he’s powering it with motors, not wind, and this has caused a few problems in transmitting mechanical power through a piece of PVC. Nothing is perfect, and in a few points in the legs movement the shaft shakes violently. One motor was lost and another nearly so before [Jeremy] came up with a flex coupler made from PVC.
The technique [Jeremy] is using has seen a lot of use with people building laser cut enclosures. It’s called kerf bending, and it works simply by cutting a few slits in a panel that allow it to bend slightly. This technique was replicated by [Jeremy] on a miter saw, cutting eight slots halfway through a one inch PVC pipe, with each successive cut offset 90 degrees.
The new design works well for transmitting power, and he’s not ruining motors any more. Check out the video below.
Filed under: robots hacks
Friday, April 4, 2014 - 10:01Throwback Handheld Built with Modern Hobby Hardware
Remember all of those fantastically horrible handheld LCD games that hit the toy stores back in the ’90s. You know, the ones that had custom LCD screens to make for some fake animation. Here’s an example of what those should have been. It’s an LCD-based handheld with some soul.
The entire thing is roughly the size of a television remote, with a 3D printed case making it very presentable. But looking at the wiring which hides inside proves this is one-of-a-kind. The Arduino Pro Mini is probably the biggest difference in technology from back in the day compared to now. It has plenty of space for all of the different settings and games shown off in the clip below. The user interface itself is definitely a throw-back though. The Nokia 3310 screen boasts a whopping 84×48 pixel monochrome area. There are four buttons serving as a d-pad, and two as action buttons. Perhaps the greatest feature (besides the printed case we already mentioned) is the ability to recharge the internal battery via USB.
[Zippy314] built this with his son. What’s more fun: learning to program the games, or mastering them and discovering the bugs you missed along the way?
[via Brad's Projects]
Friday, April 4, 2014 - 07:00Blinkenschild, The RGB LED Display For Every Occasion
One morning [overflo] decided to protest the European Parliament’s stance on equine rights of defecation, a cherished liberty dating back to the time of Charlemagne. The best way to do this is, of course, blinking lights. He calls his project Blinkenschild, and it’s one of the best portable LED displays we’ve seen.
The display is based around fifteen RGB-123 LED panels, each containing an 8×8 matrix of WS2811 LEDs. That’s 960 pixels, all controlled with a Teensy 3.1. Power is supplied by fifteen LiPo cells wired together in parallel giving him 6 Ah of battery life. Clunky, yes, but it’s small enough to fit in a backpack and that’s what [overflo] had sitting around anyway.
The animations for the display are generated by Glediator, an unfortunately not open source control app for LED matrices. Glediator sends data out over a serial port but not over IP or directly into a file. Not wanting to carry a laptop around with him, [overflo] created a virtual serial port and dumped the output of Glediator into a file so it could be
played backstored on an SD card and controlled with an Android app. Very clever, and just the thing to raise awareness of horse and Internet concerns.
UPDATE: Check out [overflo's] clarification in the comments below.
Filed under: led hacks
Friday, April 4, 2014 - 04:01Raspberry Pi UPS Using Supercapacitors
What happens when you want to integrate a Raspberry Pi into some kind of project that gets turned on and off with mains voltage? Do you power the Pi separately, or make a UPS for it?
[Lutz Lisseck] decided he wanted to turn his ambient-lamp (Rundbuntplasma) on and off with only the main power switch in his Hackerpsace. He could build a traditional UPS using a battery pack (it’s only 5V after all!) but decided to take it a step further. He picked up a pair of 50F supercapacitors. This way his UPS would last longer than his Pi would! The caps store just enough power that when the main supply is cut, a GPIO notices, tells the Pi, and it begins a shutdown sequence lasting about 30 seconds.
While [Lutz] is using two 2.7V supercapacitors, he mentions it would be a lot cheaper to use a step-up converter instead of putting them in series — but he had the caps on hand so decided to use both.
If you need it to last a bit longer, you could make one with rechargeable batteries…
Filed under: Raspberry Pi
Friday, April 4, 2014 - 01:00LightByte: Animated Shutters
Here’s another interesting project to come out of the MIT Media Lab — it’s called LightByte, and it’s all about interacting with sunlight and shadows in a new, rather unorthodox way.
We suppose its technical name could be a massive interactive sun pixel facade, but that’s a bit too much of a mouthful. What you really want to know is how it works, and the answer is, a lot of servos. We weren’t able to find an exact number but the hardware behind LightByte includes well over 100 servos, and a matrix of Arduinos to control them. While that is quite impressive by itself, it gets better — it’s actually completely interactive; recognizing gestures, responding to text messages and emails, and you can even draw pictures with the included “wand”.
We love anything mechanical like this — it’s just something about mechanical shutters that make them so awesome. Of course, reverse-engineered flip dot displays are pretty cool too! Or massive home-made flip-dot displays like this one…
Filed under: Arduino Hacks
Thursday, April 3, 2014 - 23:30Some Tips About Tips
Gather, boys and girls, while we take a moment to talk about submitting projects via the Hackaday Tips Line. Come across something really cool that you think deserves a mention on our page? Let us know about it! Did you yourself make something really cool? Tell us about that, too! It doesn’t matter if it’s a project that’s been sitting on some dark corner of the Internet for a few years. If we haven’t seen it yet, we want to.
Don’t think your project is good enough for Hackaday? You’re probably too self-critical. We’re after hacks: it’s the idea that counts. Not polished? No problem. The only thing that needs to be complete is your description of the hack.
Stick with us after the jump; we’ve got plenty of tips about tips to help you out.
So you wanna get on the front page?
The best project submissions answer these question:
- What the heck is it?
- What got you into this?
- What’d you use?
- Where’d you get that stuff?
- How does it work?
- What didn’t work? (Anything blow up?!)
- What would you do differently?
We don’t expect submissions to be a how-to guide with step-by-step instructions—though those can and usually are great—but this is your chance to show off: why not dump out some photos, videos, and links! The toughest projects for us to feature are emailed essays with a few attached photos. If you need a place to host your write-up, get busy documenting it on Hackaday Projects
Titling your emails:
Avoid vaguely titled emails and instead be clear about what you’re submitting.
Bad Title: “I did this to my brother’s car…” Did you barf in it? C’mon, give us something attention-grabbing.
Good Title: “Raspi Nav Unit for Car.” It’s clear, concise, and makes life easier for everyone.
If the tip concerns a specific Hackaday Column, put that at the front of the title. Retrotechtacular, Fail of the Week, 3D Printering, Droning On, Hacking and Philosophy, and Adventures in Hackerspacing are all recurring columns that are on the lookout for your content submissions. Help us keep them thriving by sending us tips that specifically fit those topics! Titles such as “Retrotechtacular Tip: 50′s Video on Bicycle Making” makes sorting a breeze!
Tell us how to identify you if you have a preference:
We want to credit your project and your work appropriately, which—if it’s something you have a preference about—is easier if you give us a heads up in the email. If you’d rather we use your handle, let us know you prefer to be called [snipehuntr] and not Jim-Bob. If the associated pronouns aren’t obvious, let us know those too. It is also helpful when you tell us: “this isn’t my project, but I thought it belonged on Hackaday.”
If your project wasn’t chosen:
Let’s face it, some projects don’t make it to the main page. Sometimes we pass on things because it’s poorly presented, and sometimes it slips through the cracks. Sometimes it’s…a press release. Ugh. Don’t send us those.
If you’ve submitted in the past and didn’t get featured, we don’t want to discourage you from submitting again. See if you can spruce it up with some of the above advice then hit us up again. There’s no harm in resubmitting every once in awhile.
So. Now there’s no excuse. Click that tips link and blow it up!
Thursday, April 3, 2014 - 22:00Turning The Makerbot Into A Tattoo Machine
ENSCI les Ateliers, the famous design school in Paris, had a “Public Domain Remix” and hackathon recently, with teams splitting up to remix public domain and other free-to-use IP in projects. Most of the teams came up with similar ideas, but one team went above and beyond the call of duty; they turned a 3D printer into a tattoo machine, capable of inking a real, live human test subject.
The build began by plotting a circle with a pen onto a piece of paper. This evolved into printing a tool holder for a tattoo machine graciously provided by an amateur tattoo artist. Tests with “artificial skin” (any one care to hazard a guess at what that is?) were promising, and the team moved on to a human guinea pig.
The biggest problem the team faced is that humans aren’t flat. They tried a few tricks to tighten the skin around the area to be tattooed – metal rings, elastics, and finally the inner tube from a scooter. In the end, the team was able to tattoo a small circle on the forearm of the test subject.
It’s an extremely simple and small tattoo, and scaling this build up to a sleeve would be difficult. A better solution would be to create a point cloud of an arm before going for a much larger tattoo.
Filed under: 3d Printer hacks
Thursday, April 3, 2014 - 19:01Fail of the Week: CPLDs That Release Blue Smoke
The card you see above is a floppy drive emulator for Macintosh. [Steve Chamberlain] has been hand assembling these and selling them in small runs, but is troubled by about a 4% burn-out rate for the CPLD which has the red ‘X’ on it. He settled into figure out what exactly is leading to this and it’s a real head-scratcher.
He does a very good job of trouble-shooting, starting with a list of all the possible things he thinks could be causing this: defective part, bad PCB, bad uC firmware, damage during assembly, solder short, tolerance issues, over-voltage on the DB connector, or bad VHDL design. He methodically eliminates these, first by swapping out the part and observing the exact same failure (pretty much eliminates assembly, solder short, etc.), then by measuring and scoping around the card.
The fascinating read doesn’t stop with the article. Make sure you work your way through the comments thread. [Steve] thinks he’s eliminated the idea of bad microcontroller code causing damage. He considers putting in-line resistors on the DB connector but we wonder if clamping diodes wouldn’t be a better choice (at least for testing purposes)? This begs the question, why is he observing a higher voltage on those I/O lines during power-up? As always, we want to hear your constructive comments below.
Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story – or sending in links to fail write ups you find in your Internet travels.
Thursday, April 3, 2014 - 16:01Peltier Mini-Fridge Preserves Chip Quik, Marriage
[Charles] uses Chip Quik to solder his SMD parts, and that stuff can keep for more than six months if it’s kept cool. His wife banned all non-food items from their refrigerator, so he had to think fast and came up with this Peltier effect Chip Quik cooler.
He first looked into that man cave essential, the mini-fridge, but they’re too expensive and use too much power. [Charles] got a nice wooden box from a hobby store and some reflective insulation from Lowe’s. He first tried using a couple of heat sinks but they weren’t going to cool things down enough. Once he got a Peltier cooling kit, he was in business. The temperature in his workshop averages 80°F, and he says the box gets down to 58°F. This is cold enough to keep his paste fresh.
[Charles] plans to use a PC power supply in the future rather than his bench supply. He estimates that his Peltier cooler uses 25-50% of the power that a mini-fridge would, and now his wife won’t overheat. Many great things can be accomplished with the Peltier effect from air conditioning to sous-vide cooking to LED rings. What have you used it for?
Thursday, April 3, 2014 - 13:01Tearing Down a Cheap External USB Battery
[cpldcpu] recently received an external USB battery as a promotional gift and thought it would be a good idea to tear it down to see its insides. At first glance, he could see that the device included a USB micro-b socket used as a 5V input (for charging), a USB-A socket for 5V output, a blue LED to indicate active power out and a red one to indicate charging.
Opening the case revealed that most space was taken up by a 2600mAH ICR18650 Li-Ion battery, connected to a tiny PCB. A close inspection and a little googling allowed [cpldcpu] to identify the main components of the latter: a battery mangement IC, a 2A boost converter, a 3A Schottky diode, a few 2A N-Mosfets, a 300mA 2.5V LDO and an unknown 6-pin IC. It is very interesting to learn that every last one of these components seems to be sourced from China, which may explain why this USB battery is given for free. Do you think they designed it in-house and outsourced the manufacturing, or is this a product Digi-Key simply bought and put their name on?
Editorial Note: Digi-Key is an advertiser on Hackaday but this post is not part of that sponsorship. Hackaday does not post sponsored content.
Unrelated video of extremely similar hardware. [Thanks James from comments]
Filed under: hardware
Thursday, April 3, 2014 - 10:00The Tiny, Awesome Class D Amp
In one of [Hans Peter]‘s many idle browsing sessions at a manufacturer’s website, he came across a very cool chip – a 10 Watt class D amplifier chip. After the sample order arrived, he quickly put this chip in a box and forgot about it. A year or so later, he was asked to construct a portable boom box kit for a festival. Time to break out that chip and make a small amplifier, it seems.
The chip in question – a Maxim MAX9768 – is a tiny chip, a 24-pin TQFP with 1mm pitch. Hard to solder freehand, but this chip does have a few cool features. It’s a filterless design, very easy to implement, and perfect for the mono boombox project he was working on. A simple, seven component circuit was laid out on a breadboard and [Hans] got this chip up and running.
For the festival, a breadboarded circuit wouldn’t do. He needed a better solution, something built on a PCB that would work well as a kit. The requirements included the MAX9768 chip, a guitar preamp, stereo to mono summing, and through-hole parts for easy soldering. The completed board ended up being extremely small - 33.6mm by 22.5mm – and works really great.
After the festival, [Hans] found a 20 Watt chip and designed an all-SMD version of the board. Just the thing if you ever want to stuff a tiny amplifier into a crevice of a project.
Filed under: hardware
Thursday, April 3, 2014 - 07:00Arduino Controlled Dahlander Motor Switch
[Jean-Noel] is fixing a broken Lurem woodworking machine. This machine uses a three-phase Dahlander motor, which has three operation modes: stop, half speed, and full speed. The motor uses a special mechanical switch to select the operating mode. Unfortunately, the mechanical bits inside the switch were broken, and the motor couldn’t be turned on.
To solve the problem without sourcing a new switch, [Jean-Noel] built his own Arduino based Dahlander switch. This consists of three relays that select the wiring configuration for each speed mode. There’s also a button to toggle settings, and two lamps to show what mode the motor is currently in.
The Arduino runs a finite-state machine (FSM), ensuring that the device transitions through the modes in the correct order. This is quite important, since the motor could be damaged if certain restrictions aren’t followed. The state machine graph was generated using Fizzim, a free tool that generates not only FSM graphs, but also Verilog and VHDL code for the machines.
The final product is housed in a DIN rail case, which allows it to be securely mounted along with the rest of the wiring. The detailed write-up on this project explains all the details of the motor, and the challenges of building this replacement switch.
Thursday, April 3, 2014 - 04:00Happiness Is Just A Flaming Oxy-Fuel Torch Away
The Egg-Bot is pretty awesome, we must say. But if you have one, you end up with lot of delicate, round things rolling around your abode and getting underfoot. Warmer weather is just around the corner, so segue from spring gaiety to hot fun in the summertime with the MarshMallowMatic kit from [Evil Mad Scientist].
The MarshMallowMatic is a CNC oxy-fuel precision marshmallow toaster based on the Ostrich Egg-Bot design. Constructed from flame-retardant plywood, it is sure to add an element of delicious danger to children’s birthday parties and weekend wingdings alike. You don’t have to get too specific with those BYOM invitations because this bad boy will torch standard and jumbo marshmallows like a boss.
The kit includes a 5000°F oxy-fuel torch and a 20 ft³ oxygen tank, but the tank comes empty and you’ll have to supply your own propane, acetylene, or hydrogen. It comes with adapters to fit disposable propane and MAPP cylinders, which are also not included. However, you will receive a fine selection of sample marshmallows to get you started. Watch the MarshMallowMatic fire up some happiness after the break. You could toast a special message and load it into this face-tracking confectionery cannon to show how much you care.
Thursday, April 3, 2014 - 01:003D Printed Splint Saves Baby’s Life
Here’s another heartwarming story about how 3D printers are continuing to make a real difference in the medical world. [Garrett] is just a baby whose bronchi collapse when breathing — he’s been on a ventilator for most of his life – Until now.
[Scott Hollister] is a professor of Biomedical Engineering and Mechanical Engineering, as well as being an associate professor of surgery at the University of Michigan. Between him and [Doctor Glen Green], an associate professor of Pediatric Otolaryngology, they have created a bioresorbable device that could save little [Garrett's] life.
By taking CT scans of [Garrett's] bronchi and trachea, they were able to create a 3D model and design a “splint” to help support the bronchi from collapsing during normal breathing. If all goes well, within 3 years, the splint will dissolve in his body and he will be able to breath normally for good. The material in question is a biopolymer called polycaprolactone, which they were actually granted emergency clearance from the FDA to use for [Garrett]. They used an EOS SLS based 3D printer.
The surgery was successful, and [Garrett] is now on the road to recovery. Stick around for a few videos showing of the printing process and surgery.
And [Garrett's] story: