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Hackaday Prize Entry: Messing Around With New Vacuum Tubes

อังคาร, 06/27/2017 - 01:30

Vacuum tubes have been around for ages, and for better or worse, they have their advocates for use in amplifiers and preamps. However, tubes are simply inconvenient devices. Even a 12AX7 preamp tube is huge relative to a handful of transistors, tubes require weird voltages, and each and every one of them is a through-hole device that doesn’t lend itself to machine assembly.

This changed recently with the introduction a strange new tube from Japan. Noritake and Korg recently introduced a triode that uses the same packaging as VFD displays. The Korg Nutube is a vacuum tube that operates at lower voltages, is smaller than the usual preamp tubes, and still has the vacuum tube sound.

For his Hackaday Prize entry, [Kodera] is building a headphone amp with this new tube. Is a tube-based headphone amp particularly novel? No. But this is the first we’ve seen anyone playing around with this new, interesting piece of technology.

The requirements for this Nutube are simple enough, and the minimum anode voltage of this tube is just 8 V. [Kodera]’s circuit is running the tube at 12 V, and the only other circuitry in this preamp are a few coupling caps and an op-amp just before the power stage.

[Kodera] has crammed this circuit into a proper amplifier using a 2 x 15 W class-D chip from TI. It’s really a phenomenally simple circuit that’s also remarkably tiny. These kits are actually available on Tindie. Time will tell if the Nutube is picked up by some big-time manufacturers, but we’re happy to see someone is playing around with the latest advances in tube amp technology.

The HackadayPrize2017 is Sponsored by:
Filed under: The Hackaday Prize

MEMS: The Biggest Word in Small

อังคาร, 06/27/2017 - 00:01

What’s tiny and on track to be worth $22 billion dollars by 2018? MEMS (Micro Electrical Mechanical Systems). That’s a catch-all phrase for microscopic devices that have moving parts. Usually, the component sizes range from 0.1 mm to 0.001 mm, which is tiny, indeed. There are some researchers working with even smaller components, sometimes referenced as NEMS (Nano Electrical Mechanical Systems).

Resonant Cantilever by [Pcflet01], CC BY-SA 3.0MEMS have a wide range of applications including ink jet printers, accelerometers, gyroscopes, microphones, pressure sensors, displays, and more. Many of the sensors in a typical cell phone would not be possible without MEMS. There are many ways that MEMS devices are built, but just to get a flavor, consider the cantilever (see right), one of the most common MEMS constructions.

Cantilever

In mechanical engineering, a cantilever is a rigid structure, often a beam or a plate, anchored at one end to a support. Any load applied to the cantilever transmits to the support. This is often used when building bridges, for example.

Cantilever Cross Section by [Vcaeken], CC BY-SA 3.0MEMS devices widely use cantilevers at the microscopic level. These can act as transducers for atomic force microscopes, or as resonant elements in filters and resonators. Cantilevers can also act as accelerometers. On the left, you can see a microscopic cantilever vibrating in resonance.

It is relatively straightforward to detect acceleration using a cantilever. First, you attach a microscopic proof mass to the end. Acceleration will cause that mass to move, thus stressing the cantilever. By measuring the stress on the support, you can determine the amount of acceleration force on the cantilever. By positioning cantilevers on different axes, you can read acceleration in each direction.

History

While the term itself dates back to 1986, the idea is much older. In 1959, for example, Richard Feynman lectured about the possibility of such devices. However, practical construction using semiconductor manufacturing techniques made the devices theoretical for a long time.

Even so, Feynman’s lecture anticipated a few key points to MEMS and even created two challenges. One was to construct a tiny motor and was completed using conventional tools in 1960. The other challenge had to wait until 1985 when a graduate student reduced a passage of text to be 25,000 times smaller.

Unfortunately, Feynman was ahead of his time, and building a tiny motor conventionally didn’t really advance the state of the art. One of Feynman’s key points that you could make a set of remote manipulators at, say, quarter-scale. Then you could use those manipulators to build another set at 1/16th scale and keep repeating the process. Feynman knew that you’d eventually have to change how the manipulators work because materials behave differently at scale and forces that act on things get funny as the scale goes down, too.

Future

Of course, the cantilever is just one possible device. There are MEMS temperature sensors, magnetic field sensors, radiation sensors, and more. There are microscopic motors that use electrostatic force instead of electromagnetic, micro gas valves, and optical switches.

Because the MEMS devices use semiconductor fabrication techniques, it is inviting to integrate them with conventional circuits. We are already starting to see microcontrollers with MEMS devices onboard and we expect to see that trend continue.

By the way, we covered a video done by [Engineer Guy] on this topic awhile back. You can watch it, below.

Banner image via Stanford’s QCN quake-detecting network.

 


Filed under: Engineering, Featured

A Switched Game Boy Advance SP

จันทร์, 06/26/2017 - 22:30

After Nintendo’s wild success with the Wii U, Nintendo released it’s Nintendo Switch. The switch functions primarily as a home console, stagnantly connected to a display. However, Nintendo switched things up a bit: the Switch can be removed from its dock for standalone tablet-like use. But there’s a slight problem: when the Switch is in portable mode, it leaves behind a bleak and black box. What’s one to do? Worry not: [Alexander Blake] is here to save the day with a Game Boy Advance SP and an X-Acto knife.

After casually noting that the main control board of the Switch was roughly Game Boy Advance SP sized, [Alexander Blake], aka [cptnalex], knew it was meant to be. After retrieving his broken Game Boy Advance SP from his closet, [cptnalex] set to work turning his Game Boy into a Nintendo Switch dock. When he was done, the results were stunning, especially considering the fact that this is his first console mod. Moreover, the very fact that he did it all with an X-Acto knife rather than a Dremel is astounding.

With the screen providing support to the Switch, [cptnalex’s] design leaves some to be desired for long term use. But we know for sure that [cptnalex’s] design does, in fact, work. Due to naysayers of the internetTM, [cptnalex] filmed a video of his dock in uses (embedded after the break). But, what the design lacks in structural stability, it more than makes up for in aesthetics. On the device itself, [cptnalex’s] history with controller painting shines through.

If you want to see more of [cptnalex’s] work, you can follow him on Instagram. For more console mods that will take your breath away, look no farther than [Bungle’s] vacuum formed portable N64.

Big thanks to [Itay] for sending this in.


Filed under: handhelds hacks, nintendo gameboy hacks, nintendo hacks

Hacking an Inspection Microscope

จันทร์, 06/26/2017 - 21:01

Sometimes I need to be able to take photographs of very small things, and the so-called macro mode on my point-and-shoot camera just won’t cut it. And it never hurts to have an inspection scope on hand for tiny soldering jobs, either, though I prefer a simple jeweler’s loupe in one eye for most tasks. So I sent just over $40 off to my close friend Alibaba, and a few weeks later was the proud owner of a halfway usable inspection scope that records stills or video to an SD card.

Unfortunately, it’s only halfway useable because of chintzy interface design and a wobbly mount. So I spent an afternoon, took the microscope apart, and got it under microcontroller control, complete with WiFi and a scripting language. Much better! Now I can make microscope time-lapses, but much more importantly I can take blur-free photos without touching the wiggly rig. It was a fun hack, so I thought I’d share. Read on!

Out of the Box Nice image, but don’t touch!

The scope, as it arrives, is really fun. The image is just fine and most everything works as advertised. Looking at bugs and flowers was good for a few hours at least. However, all of the small details that make for a pleasant user experience are botched.

For instance, the clearance on the SD card is so tight that you can’t insert or remove it without something thin to press it in, or having very long fingernails. Some of the buttons are hard to reach behind the big focus knob. The menu system, to turn on or off the LED ring light for instance, is horrendous. These are minor quibbles, and for the price I’m totally willing to overlook them.

But the killer, for my purposes, is that the stand is so wobbly that the act of pressing the “OK” button to take a picture blurs whatever image was there. The video mode has a “motion detection” method — it’s always on because the camera wobbles so much that it always thinks the object has just moved. The culprit is the cheesy frame that ends in a thick silicone suction cup that wiggles around like a bowl of jelly. This is not how you design tripods.

There are two possible fixes for the vibration issue. The first is to build a better frame, and that’s something I’ll probably end up doing eventually, because the inspection scope is a useful piece of gear. The other solution is simply to trigger the exposure (and other) buttons without touching the wiggly little beast. Welcome to the Internet of Microscopes!

Hack, Hack, Hack

Opening up the case, the first thing I found was a row of five test points on the key panel, so I soldered some header wires to them to see what’s up. (That was easy!) They’re labelled GND, VCC, KEY, PWR, and VBAT, which doesn’t leave much to the imagination. Four out of the five are labelled correctly.

I’m an analog hacker at heart, and I usually start off with an oscilloscope when poking around unknown signals, but I decided to start off with a logic probe this time, because surely the single KEY line was encoding the five front-panel buttons in some sort of digital code. Imagine my surprise when each button press looked identical on the logic sniffer. Burned again. Back to the trusty oscilloscope.

Five buttons, five voltages

It turns out that the five buttons are tied to five different resistors that serve as the lower half of a voltage divider, and an ADC reads this voltage out to figure out which key was pressed. That explains the five voltage levels on the yellow scope trace.

This is a classic dirty trick and I’ve been waiting for the day when I absolutely had to minimize the number of wires connected to a panel. Who knew that I’d see something hackish like this in an actual product?

The power button is separate and pulls the PWR line (in green on the scope trace, on a 5 V vertical scale) to the VBAT line. A quick test with a 3.3 V power supply convinced me that I could turn the device on and off with a microcontroller’s GPIO. I was also pretty sure that I could connect up five GPIO pins to different resistors and “press” the corresponding button. So I pulled off the panel to measure the individual resistors.

In case you want to replicate this at home, the resistors are 0 Ω, 15 kΩ, 30 kΩ, 46.6 kΩ, and 70 kΩ respectively, and doing a little math on the measured voltages, the pullup resistor on the top of the voltage divider is probably nominally 100 kΩ. Alternatively, if you have a DAC you could just send voltages of 0 V, 400 mV, 750 mV, 975 mV, or 1325 mV to the KEY pin. I soldered up the closest resistors I had in my box, verified that they all worked and called the hardware done.

But what’s up with the VCC line? Something didn’t make sense, because the buttons pulled the voltage down despite being connected to VCC, and the KEY line was pulled high by default. Testing it out, of course VCC was a dead-short to GND and the pull-up resistor was on the KEY line. There was an unpopulated resistor on the keypad panel PCB as well, suggesting that in a previous revision the buttons pulled up, but the manufacturer optimized away a single resistor by using the microcontroller’s internal pullup. It’s either laziness or deliberate sabotage that they didn’t change the test-point silkscreen to match. (Imagine how much fun it would be to connect your test equipment up to “VCC” and GND!)

The Usual Suspects

The rest of the work was just me using my favorite tools for a quick job like this. You might want to use an Arduino or a single ESP8266, but I’ve been playing around with Mecrisp-Stellaris Forth on cheap STM32F103 boards lately, so that’s where I went. I was originally thinking of making a custom remote key panel, so the many GPIO pins would have meant that I wouldn’t have to resort to the ADC-and-resistors trick.

I was already using UART serial for programming and debugging, and decided that a separate key panel was a project in its own, so I cheesed out and put the microscope on the WiFi network. I flashed an ESP8266 with the esp-link WiFi-serial bridge firmware. Voila, remote control. Powering the microcontrollers off of the microscope’s VBAT line (through a switch) makes the whole thing entirely self-contained when I have to move it around the desk.

There were many details that required trial-and-error testing to get right. Different delays are required for button presses in camera mode and in the menu system, for instance. I didn’t optimize these, but made the delay long enough that it always works. The power on and off button only works if held down for longer than 1.5 seconds. It’s quirky. This was all pretty quick to get working with an interactive debugging system like the Forth environment, although I don’t think it would be all that much worse in a compile-and-flash loop like in C or Arduino either.

More guts, just for completeness

There are two cute things that I did in the firmware that are worth mentioning. The KEY line that’s used to detect button presses is only pulled up when the microscope’s power is on, so it can be read by the microcontroller to figure out if the microscope is currently on or off. When the microscope first turns on, it is in video mode, which allows the software to keep track internally of the mode it’s currently in.

Combined, this allows for a single “shoot” command that first verifies that the microscope is on, then switches into camera mode if it’s not already there, and then finally takes a photo. Similarly a “delete” command switches over to preview mode and deletes the last photo, confirming all of the “are you sure?” dialogs automatically. The code is here if you’re interested.

Making it Usable and Then Some

The out-of-the-box menu system is horrible. It requires something like fifteen keypresses to toggle the ring light on or off. Scripting this in the microcontroller makes it a lot more pleasant. Moreover, it’s now possible to set up repetitive exposures to make time-lapses, or film a two-minute video once every ten minutes, or automate essentially anything. I might add a distance sensor to make filming automatic when a PCB is present under the lens, or something silly. I really like the idea of tying these script functionalities to external buttons: a one-press light toggle or bracketed exposure button would be nice, as would a single-button delete.

The world is now my oyster, so expect to see a lot more super-closeup footage in upcoming Hackaday articles. And if you pick up one of these microscopes, don’t hesitate to open it up, solder a handful of resistors in, and take control of it yourself. You’ll probably find it useful enough that you’ll build it a proper stand, but that’s another story.


Filed under: Engineering, Featured, reviews

Fidget-Spinning Robot Out-Uselesses Other Useless Machines

จันทร์, 06/26/2017 - 18:00

When the [Director of Legal Evil] at Louisville’s LVL1 Hackerspace decided to demonstrate the uselessness of a 3D printer by printing a fidget spinner, another member at the space’s Tuesday meeting rose to the challenge and built a machine that whose sole purpose is to spin fidget spinners.

[Gary Flispart] used an Arduino clone and what appears to be a motor driver in conjunction with a stepper motor. The motor moves a belt that turns a series of metal scraps serving as a four-bar linkage. The linkage moves the dowel that turns the spinner and then gets out of the way so it doesn’t inhibit the toy’s rotation. The Digital Fidget Digit, as [Gary] calls it, looks like it was built out of scrap metal and random pieces of wood in the glorious tradition of hackerspace projects.

We at Hackaday love crazy projects that come out of hackerspaces, like the iris porthole at i3Detroit, another space’s ultimate fume extractor, and LVL1’s doomcano.

Thanks, [JAC_101]!


Filed under: Hackerspaces

A Table From Beyond Infinity

จันทร์, 06/26/2017 - 15:00

Infinity mirrors are some far-out table mods and make a great centerpiece. Instructables user [bongoboy23] took a couple steps beyond infinity when designing this incredible table tailor-made for our modern age.

Poplar and pine wood make up the framing, and red oak — stained and engraved — make for a chic exterior. Programmed with Arduino and run on a Teensy 3.1, the tabletop has 960 LEDs in forty sections. There are, four USB ports hidden behind sliding panels, as well as a two-port AC outlet and an inductive charging pad and circuit.  A hidden Adafruit TFT touchscreen display allows the user to control the table’s functions. Control is limited to changing lighting functions, but Pac-Man, Snake, and text features are still to come!

Weighing in at $850, it’s not a cheap build, but it looks amazing.

This is one of the most extensive Instructables you may happen across, containing dozens of pictures, CAD files, diagrams, appendices, and a change log, with tips besides; if you want one just like this at home, you are in good hands, here. Or try an easier build, we won’t judge. However, maker beware — you may be stepping through a portal that’s difficult to return from.

[Thanks for the tip, JohnL!]


Filed under: Arduino Hacks, how-to, led hacks

TEMPEST In A Software Defined Radio

จันทร์, 06/26/2017 - 12:00

In 1985, [Wim van Eck] published several technical reports on obtaining information the electromagnetic emissions of computer systems. In one analysis, [van Eck] reliably obtained data from a computer system over hundreds of meters using just a handful of components and a TV set. There were obvious security implications, and now computer systems handling highly classified data are TEMPEST shielded – an NSA specification for protection from this van Eck phreaking.

Methods of van Eck phreaking are as numerous as they are awesome. [Craig Ramsay] at Fox It has demonstrated a new method of this interesting side-channel analysis using readily available hardware (PDF warning) that includes the ubiquitous RTL-SDR USB dongle.

The experimental setup for this research involved implementing AES encryption on two FPGA boards, a SmartFusion 2 SOC and a Xilinx Pynq board. After signaling the board to run its encryption routine, analog measurement was performed on various SDRs, recorded, processed, and each byte of the key recovered.

The results from different tests show the AES key can be extracted reliably in any environment, provided the antenna is in direct contact with the device under test. Using an improvised Faraday cage constructed out of mylar space blankets, the key can be reliably extracted at a distance of 30 centimeters. In an anechoic chamber, the key can be extracted over a distance of one meter. While this is a proof of concept, if this attack requires direct, physical access to the device, the attacker is an idiot for using this method; physical access is root access.

However, this is a novel use of software defined radio. As far as the experiment itself is concerned, the same result could be obtained much more quickly with a more relevant side-channel analysis device. The ChipWhisperer, for example, can extract AES keys using power signal analysis. The ChipWhisperer does require a direct, physical access to a device, but if the alternative doesn’t work beyond one meter that shouldn’t be a problem.


Filed under: radio hacks

Flash a Light Bulb, Win a Prize

จันทร์, 06/26/2017 - 09:00

How many geeks does it take to flash a lightbulb? Judging from the list of entries in the 2017 Flashing Light Prize, so far only seven. But we suspect Hackaday readers can add to that total.

The goal is almost as simple as possible: build something that can flash an incandescent light bulb for at least five minutes. The system actually has to power the bulb’s filament, so no mechanical shutters are allowed. Other than that, the sky is the limit — any voltage, any wattage, any frequency and duty cycle, and any circuit. Some of the obvious circuits, like an RC network on a relay, have been tried. But we assume there will be points for style, in which case this sculptural cascading relay flasher might have a chance. Rube Goldberg mechanical approaches are encouraged, as in this motor, thread, stick and switch contraption. But our fave thus far is the 1000-watt bulb with solar cell feedback by Hackaday regular [mikeselectricstuff].

Get your entry in before August 1st and you’ll be on your way to glory and riches — if your definition of rich is the £200 prize. What the heck, your chances are great right now, and it’s enough for a few pints with your mates. Just don’t let it distract you from working on your 2017 Hackaday Prize entry — we’re currently in the “Wheels, Wings, and Walkers” phase, so maybe there’ll be a little crossover that you can leverage for your flasher.

Thanks to [db] for the tip.


Filed under: contests, news

Hackaday Links: June 25th, 2017

จันทร์, 06/26/2017 - 06:00

There will be no special badges for DEFCON. Everyone will still have badges — and our expectations are tempered because of the one year on / one year off schedule for electronic badges — there just won’t be mind-bending puzzles wrapped up in the official badges. What this means: it probably won’t matter if you’re late for linecon, and someone in the DEFCON hive mind still has a Facebook. Also, DEFCON is canceled.

In the past, we have decried the very existence of fidget spinners. It’s what the kids are into, after all. However, an electronic fidget spinner is an interesting engineering challenge. It combines the mechanical fun of bearing science, the exacting precision of balancing stuff, and stuffing electronics where no electronics should be. This Kickstarter is perhaps the best electronic fidget spinner we’ve seen. The electronics are powered by a coin cell and are packed into one of the spaces for the ‘wing’ bearings, and two additional weighted bearings allow the spinner to balance. There’s a small magnet for a hall effect sensor in the ‘stator cap’ so RPM can be measured. This design uses the most common mold for a fidget spinner, making it very manufacturable. Compare this design to the Internet of Fidget Spinners, a POV fidget Spinner, another POV fidget spinner, an educational electronic fidget spinner, or this amazing technique to measure the speed of a fidget spinner that will blow your mind, and you’ll see this Kickstarter project is clearly the superior design.

You kids are spoiled with your programmable drum machines like your 808 and 909. Back in the day, drum machines were attached to organs, and only had a few patterns. You couldn’t change the patterns, you could only change the speed. [Jan] has created one of these prehistoric drum machines in a microcontroller. You get hard rock, disco, reggae, rock, samba, rumba, cha-cha, bossa nova, beguine, synthpop, boogie, waltz, jazz rock, and slow rock. Awesome.

There’s a new electronics magazine. It’s called DIYODE, and we’re all kicking ourselves for not coming up with that name.

Do you need a new password? Humans really aren’t good at coming up with random numbers, and if you need a completely random alphanumeric password, it’s best left to a computer. Have no fear, because there’s now a website that generates the single most secure password on the planet. This password, “H4!b5at+kWls-8yh4Guq”, features upper and lowercase characters, numbers, symbols, and twenty unique characters. This password was developed by security researchers and encryption specialists in Europe, so you know it has absolutely nothing to do with the NSA, CIA, or any other American three-letter agency.

Speaking of three-letter agencies, last Wednesday was International Selfie Day! That doesn’t mean you still can’t get in on the action. Take a selfie right now and upload it to social media! What’s facial recognition?

Looking for a great little ESP32 breakout board with all the bells and whistles? Olimex has a new board out with Ethernet, a MicroSD card slot, and 20 GPIOs broken out.


Filed under: Hackaday Columns, Hackaday links

Hackaday Prize Entry: Modular Circuits with SnapBloks

จันทร์, 06/26/2017 - 03:00

[Ekawahyu Susilo]’s twist on the modular circuit kit, SnapBloks helps you create circuits by stacking components on top of each other with the help of three magnetic contacts that not only keep the modules stuck together but also deliver power, ground, and data to each part.

[Ekawahyu] envisioned it as a prototyping kit, used to whip together an idea without a lot of hassle. It could also be an educational aid, used to teach Arduino coding while skipping the confusing tangle of wiring. You can stack a sound module on top of a power module to make a buzzer, or attach power to a wheel Blok to make a robot.

With version 2 of the project [Ekawahyu] updated the look with color-coded shells, with pink signifying input Bloks, green for output, orange for communication, and blue for power. Each Blok has a Arduino chip inside — an STM32, which Hackaday reviewed back in March. For version three, he hopes to leverage the ESP8266 to make a WiFi-enabled Blok. [Ekawahyu]’s idea of having a cheap SMD Arduino in every module seems like a smart way to simplify module creation—no “controller block” needed!

The HackadayPrize2017 is Sponsored by:
Filed under: The Hackaday Prize

Another Helping Hands Build

จันทร์, 06/26/2017 - 00:00

[Punamenon2] wanted a soldering station with integrated helping hands. He couldn’t find one, but he decided it would be a good 3D printed project. In all fairness, this is really 3D printing integrating several off-the-shelf components including a magnifier, a soldering iron holder, a soldering iron cleaner, a couple of “octopus” tripods, and some alligator clips. Total cost? Less than $30.

In addition to holding the Frankenstein monster together, the 3D printed structure also provides a storage tray with special sloped edges to make removing small screws easier.

We were a bit surprised at the use of the cell phone tripods for the arms. Usually, we see these builds using machining coolant pipe. To fit the alligator clips to the tripod, [Punamenon2] had to drill some holes in the arm, whereas the coolant hoses are easy to work with.

We were a little disappointed to not find the STL files for the base, but on the other hand, you’d probably have to customize it for whatever parts you had on hand anyway. We also wondered if the base ought to have a place to fill it with sand or something for weight. Of course, you can find plenty of similar builds on Thingiverse, including printable arms, if you want to borrow a few parts for your design. We’ve seen some similar builds before, and each one is a little different. There’s also plenty of other options.


Filed under: 3d Printer hacks, tool hacks

iPad, not Flux Capacitor, Brings DeLorean Back to the Future

อาทิตย์, 06/25/2017 - 21:00

Add a flux capacitor and a Mr. Fusion to a DeLorean and it becomes a time machine. But without those, a DeLorean is just a car. A 35-year old car at that, and thus lacking even the most basic modern amenities. No GPS, no Bluetooth — not even remote locks for the gullwing doors!

To fix that, [TheKingofDub] decided to deck his DeLorean out with an iPad dash computer that upgrades the cockpit experience, and we have to say we’re impressed by the results. Luckily, the space occupied by the original stereo and dash vents in the center console is the perfect size for an iPad mini, even with the Lightning cable and audio extension cable attached. A Bluetooth relay module is used to interface to the doors, windows, trunk, garage door remote, and outdoor temperature sensor. A WiFi backup camera frames the rear license plate. Custom software ties everything together with OEM-looking icons and a big GPS speedometer. The build looks great, adds functionality, and should make road trips a little easier.

When [TheKingofDub] finally gets sick of people complaining about where the BTTF guts are, maybe he can add a flux capacitor and time circuits.

[via r/electronics]


Filed under: car hacks, transportation hacks

Animated Bathroom Sign

อาทิตย์, 06/25/2017 - 18:00

Once upon a time, pants were created. After a while, women were allowed to wear them too. This has made a lot of people happy and been widely regarded as a good thing. There is a problem, however – bathroom signage is largely predicated on the idea that there are two rigid genders which all humans must be sorted into, and they’re defined by whether you’re wearing pants or a dress. [Robb Godshaw], among others, disagrees with this, and set about building a gender fluid bathroom sign.

The sign assembled on the motor.

The project seeks to exploit the traditional symbols of “male” and “female” – the human figures wearing pants or a dress – by creating a sign that switches between the two every 15 seconds. This is likely to initially confuse – one might imagine the bathroom is actually changing its gender designation rapidly, forcing users to complete their business in an incredibly short timeframe. However, the message behind the project is to highlight the absurdity of defining gender by pants, colours, or indeed in a binary nature at all. [Robb] also helpfully points out that all humans have to pass waste, regardless of gender.

The sign is built with 3D-printed components, using a crank mechanism to actuate the moving parts. The mechanism is designed to give equal time to the pants and dress configurations. [Robb] shares the important details necessary to replicate the build, such as how to assemble the metal crank pin insert with a paperclip and a lighter. It’s particularly tidy the way the mechanism is integrated into the parts themselves. In true hacker style, the motor is a standard microwave oven turntable motor, which can be harvested easily from a junk appliance and can be plugged straight into mains power to operate, if you know what you’re doing. If you don’t, check out our primer on the topic.

Overall, the project is a great use of hacker techniques, like 3D printing and harvesting parts, to make a statement and start a conversation, while being fun, to boot. We’ve also seen some of [Robb]’s work before, like this giant hamster wheel for people. Video after the break.

 


Filed under: 3d Printer hacks

Dirty Now Does Cables

อาทิตย์, 06/25/2017 - 15:00

PCB makers Dirty made a name for themselves in the prototype PCB biz, with a convenient web form and numerous options for PCB color, thickness, layers, silk screening, and so on. Now they’ve branched out into custom cabling with Dirty Cables.

You can design it yourself by dragging wires and connectors out of a sidebar and arranging them on a workspace, deciding which wire goes to what pin of the connector. Your choices for wires include various gauges and ribbon configurations. You choose a color (they have eleven) select connectors and drag those out too–choose from 17 cable-to-cable and cable-to-board connector families. We made a quick cable with four 32ga wires and two 16ga wires, with two different connectors on each side, with pricing updated realtime. If you want a sample pack of connectors, Dirty sells them for $10.

The downside to the service: there’s a minimum order of 100, though paying Shenzhen prices might make it worth your while. Just imagining crimping all of those connectors makes Hackaday’s hands hurt.

To get a sense of the diversity of connectors out there, read Elliot’s piece on the connector zoo that we published last year.

[thanks, Akiba]


Filed under: hardware

Listen to your Body

อาทิตย์, 06/25/2017 - 12:00

[John Miller] has the perfect response next time he complains about an ache or pain and one of his friends says, “You should listen to your body!” As you can see in the video below, he already does. Using two 9V batteries and some instrumentation amplifiers, [John] built an electromyography (EMG) rig.

If you haven’t heard of EMG, think of EEG or EKG, but for muscles instead of your brain or your heart. The LT1167 amplifier is well-suited for this application and even has a data sheet showing how to create an EMG circuit. [John] also used some more garden-variety op amps and the ubiquitous LM386N chip for audio amplification.

This isn’t the first EMG rig we’ve seen, but [John] does a nice job of explaining why such a special amplifier is used and how it works. He also provides a lot of pointers to more detailed information, including a paper that covers the safety aspects of hooking yourself — or anyone — up to electronics.

The op amps require a dual polarity power supply, so the project uses two 9V batteries. Not only is this handy, but it eliminates any concerns about the device that connects to you getting power from the wall.

Why do you want to listen to muscles? Maybe just to do it, which is a perfectly good excuse around here. However, it is possible to use the signals to control devices like prosthetic limbs, cursors, and more. You can even move someone else’s arm with the right equipment.

We’ve covered an open source muscle interface as part of our Hackaday prizes. Our own [Bil Herd] has even used himself as a guinea pig.


Filed under: Medical hacks

3D-Printed Rover Rolls Light and Looks Right

อาทิตย์, 06/25/2017 - 09:00

[Rick Winscott]’s RO-V Remotely Operated Vehicle instructable shows you how to make this cool-looking and capable robot. The rover, a 1/10th scale truggy, sports a chassis printed in silver and black PLA. It’s got a wireless router mounted on the back, and a webcam in a 2-servo gimbal up front. [Rick] made his own steering rack and pinion out of 3D printed parts and brass M3-threaded rods which he tapped himself.

The simplified drive system nixes the front, rear, and center differentials, thereby saving [Rick] on printing time, complexity, and weight — he was able to include a second 4000 mAH battery. A TReX Jr motor controller runs a pair of Pololu gear motors. All of this is controlled by a Beaglebone Black alongside a Spektrum DX6i 2.4Ghz transmitter and an OrangeRx 6-channel receiver. The DX6i [Rick] employs typically finds use as an airplane/quad controller, but he reconfigured it to steer the rover—the left stick controls direction and the right stick (elevator and aileron) control the webcam servos.

Enough talking technicals. We think this rover is pretty in the face. Much of this attraction owes to the set of Dagu Wild Thumper wheels (an entirely reasonable name) and the awe-inspiring 100mm shocks that jack up this whip so pleasingly. However, [Rick]’s elegant chassis and the silver-and-black color scheme doesn’t hurt one bit. The wheels are mostly for the cool factor, however—[Rick] recommends swapping out the relatively modest Pololu 20D gear motors in favor of higher-torque models if you’re planning any actual off-road extremeness. If you’re interested in making your own you can download the chassis files from Tinkercad or the BeagleBone code from Github.

If it’s other drone projects you’re after, check out the duct rover and solar wifi rover we published recently.


Filed under: drone hacks

A Goldmine Of Radio Shack Goodies Is Up For Auction

อาทิตย์, 06/25/2017 - 06:00

Where did you buy the parts for your first electronic project? That’s a question likely to prompt a misty-eyed orgy of reminiscences from many Hackaday readers, if ever we have heard one. The chances are that if you are from North America or substantial parts of the English-speaking world, you bought them from a store that was part of the Radio Shack empire. These modestly sized stores in your local mall or shopping centre carried a unique mix of consumer electronics, CB radio, computers, and electronic components, and particularly in the days before the World Wide Web were one of very few places in which an experimenter could buy such parts over the counter.

Sadly for fans of retail electronic component shopping, the company behind the Radio Shack stores faltered in the face of its new online competition over later years of the last decade, finally reaching bankruptcy in 2015. Gone are all but a few independently owned stores, and the brand survives as an online electronics retailer.

The glory days of Radio Shack may be long gone, but its remaining parts are still capable of turning up a few surprises. As part of the company’s archives they had retained a huge trove of Radio Shack products and memorabilia, and these have been put up for sale in an online auction.

There is such a range if items for sale that if you are like us you will probably find yourself browsing the listings for quite a while. Some of it is the paraphernalia of a corporate head-office, such as framed artwork, corporate logos, or strangely, portraits of [George W. Bush], but the bulk of the collection will be of more interest. There are catalogues galore from much of the company’s history, items from many of its promotions over the years including its ventures into sporting sponsorship, and numerous examples of Radio Shack products. You will find most of the computers, including a significant number of TRS-80s and accessories, tube-based radios and equipment from the 1950s, as well as cardboard boxes stuffed with more recent Realistic-branded items. There are even a few retail technology dead ends to be found, such as a box of :CueCat barcode readers that they evidently couldn’t give away back in the dotcom boom.

If you are interested in any of the Radio Shack lots, you have until the 3rd of July to snap up your personal piece of retail electronic history. Meanwhile if you are interested in the events that led to this moment, you can read our coverage of the retail chain’s demise.

Thanks [Mark Scott] for the tip.


Filed under: misc hacks, news

Hackaday Prize Entry: A 3D Printer Management System

อาทิตย์, 06/25/2017 - 03:00

Since the first desktop 3D printers, people have been trying to figure out a way to manage desktop 3D printers and turn them into tiny little automated factories. One of the first efforts was a conveyor belt build plate that was successfully used by MakerBot until it wasn’t anymore. Octoprint has been a boon for anyone who wants to manage a few printers, but that’s only half the solution.

For his Hackaday Prize entry, [Mike] has come up with a solution that turns a desktop 3D printer into a completely automated factory. Not only does this project take care of removing the part from the bed when the print is done, it also manages a web-based print queue. It is the simplest way to manage a printer we’ve ever seen, and it’s a great entry for the Hackaday Prize.

First up, the software stack. [Mike] has developed a web-based queue and slicing software that ingests 3D models and spits out Gcode to a printer. This, really, is nothing new. Octoprint does it, Astroprint does it, and even a few 3D printers have this capability. This is only one part of the project though, although it is geared more as a maker space management software than simply a dedicated 3D printer controller.

You can’t have an automated mini factory without an automated build plate, though, and here [Mike] has come up with something really great. His solution for dispensing prints after they’re completed is brilliant in its simplicity. All you need to do is drop the floor out from underneath the print. [Mike]’s solution is a trap door print bed. At the beginning of the print, an inkjet printer spits out a piece of paper, with a few lines of text, onto the print bed. When the print is finished, a stepper motor unwinds a cable, and a trap door opens up underneath the print. The part drops into a bin, the door closes, and the next print is loaded up in the queue. It’s brilliantly simple.

You can check out [Mike]’s demo of this system after the break. It’s awesome and so sublimely simple we’re shocked no one has thought of this before.

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Filed under: 3d Printer hacks, The Hackaday Prize

12-Foot Guitar Takes The Stage

อาทิตย์, 06/25/2017 - 00:00

Musical festivals are fun and exciting. They are an opportunity for people to perform and show-off their art. The Boulevardia event held this June in Kansas City was one such event, where one of the interactive exhibits was a 12-foot guitar that could be played. [Chris Riebschlager] shares his experience making this instrument which was intended to welcome the visitors at the event.

The heart of this beautiful installation is a Bare Conductive board which is used to detect a touch on the strings. This information is sent over serial communication to a Raspberry Pi which then selects corresponding WAV files to be played. Additional arcade buttons enable the selection of playable chords from A through G, both major and minor and also give the option to put the guitar in either clean or dirty mode.

The simplicity of construction is amazing. The capacitive touch board is programmed using the Arduino IDE and the code is available as a Gist. The Raspberry Pi runs a Python script which makes the system behave like an actual guitar i.e. touching and holding the strings silences it while releasing the strings produces the relevant sound. The notes being played were exported guitar notes from Garage Band for better consistency.

The physical construction is composed of MDF and steel with the body and neck of the guitar milled on a CNC machine. Paint, finishing and custom decals give the finished project a rocking appearance. Check out the videos below for the fabrication process along with photos of the finished design.

This project is a great example of art enabled by technology and if you love guitars, then go ahead and check out Brian May’s Handmade Guitar.


Filed under: musical hacks

Fail of the Week: Tracking Meteors with Weather Radio

เสาร์, 06/24/2017 - 21:00

It’s not hard to detect meteors: go outside on a clear night in a dark place and you’re bound to see one eventually. But visible light detection is limiting, and knowing that meteors leave a trail of ions means radio detection is possible. That’s what’s behind this attempt to map meteor trails using broadcast signals, which so far hasn’t yielded great results.

Passing jet’s Doppler signature

The fact that meteor trails reflect radio signals is well-known; hams use “meteor bounce” to make long-distance contacts all the time. And using commercial FM broadcast signals to map meteor activity isn’t new, either — we’ve covered the “forward scattering” technique before. The technique requires tuning into a frequency used by a distant station but not a local one and waiting for a passing meteor to bounce the distant signal back to your SDR dongle. Capturing the waterfall display for later analysis should show characteristic patterns and give you an idea of where and when the meteor passed.

[Dave Venne] is an amateur astronomer who turns his eyes and ears to the heavens just to see what he can find. [Dave]’s problem is that the commercial FM band in the Minneapolis area that he calls home is crowded, to say the least. He hit upon the idea of using the National Weather Service weather radio broadcasts at around 160 MHz as a substitute. Sadly, all he managed to capture were passing airplanes with their characteristic Doppler shift; pretty cool in its own right, but not the desired result.

The comments in the RTL-SDR.com post on [Dave]’s attempt had a few ideas on where this went wrong and how to improve it, including the intriguing idea of using 60-meter ham band propagation beacons. Now it’s Hackaday’s turn: any ideas on how to fix [Dave]’s problem? Sound off in the comments below.


Filed under: Fail of the Week, radio hacks