Author: Adam Fabio

733 Articles

DC Motor Whirligig Generates Power

July 21, 2017 by 25 Comments

Everyone knows that if you spin the shaft of a DC motor, it will generate power. [Vapsvus] has found a novel way to do this with no direct mechanical connection to the shaft. He simply taped a loop of string around to the motor can. This effectively turns the motor into a whirligig. Flip the motor to give the string a few twists, then pull on the two loops. The string unwinds and then winds back up, just like the toy we all grew up with.

The interesting thing is that the motor generates usable power when being spun like this. [Vapsvus] connected two LEDs to the motor’s leads to show what’s happening. The white LED glows when current travels from positive to negative, and the red LED glows when current travels from negative to positive.

What’s going on under the hood is all about momentum. As the motor can starts to spin, the heavy iron rotor remains still. Power is generated. Eventually, friction and torque from back EMF cause the rotor to spin as well. By the time the rotor is spinning, the motor can is already reversing direction.This generates even more power with current traveling in reverse.

Sure, this isn’t exactly practical, but we’d love to see how far it could be taken. Add a super capacitor, and we bet it would be more efficient than the magnetic shake lights which were popular a few years back.

Whirligigs are usefully little devices. Not only do they keep children entertained, you can use them as centrifuges.

Continue reading “DC Motor Whirligig Generates Power” →

Charge Your Phone On An Iron Throne

July 20, 2017 by 8 Comments

Game of Thrones season 7 is finally here! [Hoecrux] is celebrating by building a GoT inspired cell phone charger. No, this isn’t a 3D print, nor is it vacuum molded. This iron throne was hand made from hundreds of cocktail swords. The frame of the chair is made from medium density fiberboard (MDF). The frame is covered with upholstery foam, then a layer of thin gray foam which forms the surface of the chair.

[Hoecrux] then began the painstaking process of hot gluing 600 cocktail swords to her creation. Each sword had to be modified by cutting off the loop guard. Some of the swords are bent, which was achieved with a heat gun. The completed chair was finished with a coat of black spray paint, followed by dry brushing with acrylic silver paint.

This particular iron throne charger is built for an android phone. [Hoecrux] embedded a micro USB cable in the base of the seat. If you’re of the iOS persuasion, you can substitute a lightning cable.

Check out the video after the link, and while you’re at it, get a look at this beach ready solar charger setup.

Continue reading “Charge Your Phone On An Iron Throne” →

Books You Should Read: The Bridge

July 14, 2017 by 95 Comments

A few weeks ago, Amazon’s crack marketing AI decided to recommend a few books for me. That AI must be getting better because instead of the latest special-edition Twilight books, I was greeted with this:

“The asteroid was called the Hand of God when it hit.”

That’s the first sentence of The Bridge, a new Sci-Fi book by Leonard Petracci. If you think that line sucks you in, wait until you read the whole first chapter.

The Bridge is solidly in the generation ship trope. A voyage hundreds or even thousands of years long, with no sleep or stasis pods. The original crew knows they have no hope of seeing their destination, nor will their children and grandchildren. Heinlein delved into it with Orphans of the Sky. Even Robert Goddard himself discussed generation ships in The Last Migration.

I wouldn’t call The Bridge hard Sci-Fi — and that’s perfectly fine. Leonard isn’t going for scientific accuracy. It’s a great character driven story. If you enjoyed a book like Ready Player One, you’ll probably enjoy this.

The Bridge Is the story of Dandelion 14, a ship carrying people of Earth to a new planet. At some point during the journey, Dandelion 14 was struck by an asteroid, which split the ship in two. Only a few wires and cables keep the halves of the ship together. The crew on both sides of the ship survived, but they had no way to communicate. They do catch glimpses of each other in the windows though.

Much of the story is told in the first person by Horatius, a young man born hundreds of years after the asteroid strike. Horatius’ side of the ship has a population of one thousand, carefully measured at each census. They’ve lost knowledge of how to operate the ship’s systems, but they are surviving. Most of the population are gardeners, but there are doctors, cooks, porters, and a few historians. At four years old, Horatius is selected to become a gardener, like his father was before him. But Horatius has higher aspirations. He longs to become a historian to learn the secrets of the generations that came before him and to write his own story down for those who will come after.

Horatius sees the faces of the people on the other side of the ship as well. Gaunt, hungry, often fighting with knives or other weapons. A stark contrast to the well-fed people on his side of the vessel. The exception is one red-haired girl about his age. He often finds her staring back at him, watching him.

Horatius might have been chosen as a gardener, but he’s clever — a fact that sometimes gets him in trouble. His life takes an abrupt turn when the sleeping ship awakens with an announcement blaring “Systems Rebooting, Ship damage assessed. Reuniting the two halves of the ship and restoring airlock, approximately twenty-four hours until complete.”

The hardest part of writing a book review is not giving too much away. While I won’t tell you much more about the plot for The Bridge, I can tell a bit about how the book came about. You might call this book a hack of the publishing system. Leonard Petracci is also known as leoduhvinci on Reddit. The Bridge started life as Leonard’s response to a post on /r/writingprompts. The prompt went like this:

After almost 1,000 years the population of a generation ship has lost the ability to understand most technology and now lives at a pre-industrial level. Today the ship reaches its destination and the automated systems come back online.

Leonard ’s response to the prompt shot straight to the top, and became the first chapter of The Bridge. Chapter 2 followed soon after. In only a few months, the book was complete. Available on Reddit, and on Leonard’s website. The Bridge is also available on Amazon for Kindle, and on paper from Amazon’s CreateSpace.

The only real criticism I have about The Bridge is the ending. The book’s resolution felt a bit rushed. It would have been nice to have a few more pages telling us what happened to the characters after the major events of the book. Leonard is planning a sequel though, and he teases this in the final pages.

You can start reading The Bridge right now on Leonard’s website. He has the entire book online for free for a few more weeks. If you’ve missed the free period, the Kindle edition is currently $2.99.

EMMC To SD Hack Rescues Data From A Waterlogged Phone

July 12, 2017 by 59 Comments

How do I get the data off this destroyed phone? It’s a question many of us have had to ponder – either ourselves or for friends or family. The easy answer is either spend a mint for a recovery service or consider it lost forever.  [Trochilidae] didn’t accept either of those options, so he broke out the soldering iron and rescued his own data.

A moment’s inattention with a child near a paddling pool left [Trochilidae’s] coworker’s wife with a waterlogged, dead phone. She immediately took apart the phone and attempted to dry it out, but it was too late. The phone was a goner. It also had four months of photos and other priceless data on it. [Trochilidae] was brought in to try to recover the data.

The phone was dead, but chances are the data stored within it was fine. Most devices built in the last few years use eMMC flash devices as their secondary storage. eMMC stands for Embedded Multimedia Card. What it means is that the device not only holds the flash memory array, it also contains a flash controller which handles wear leveling, flash writing, and host interface. The controller can be configured to respond exactly like a standard SD card.

The hard part is getting a tiny 153 ball BGA package to fit into an SD card slot.  [Trochilidae] accomplished that by cutting open a microSD to SD adapter. He then carefully soldered the balls from the eMMC to the pins of the adapter. Thin gauge wire, a fine tip iron, and a microscope are essentials here. Once the physical connections were made,  [Trochilidae] plugged the card into his Linux machine. The card was recognized, and he managed to pull all the data off with a single dd command.

[Trochilidae] doesn’t say what happened after the data was copied, but we’re guessing he analyzed the dump to determine the filesystem, then mounted it as a drive. The end result was a ton of recovered photos and a very happy coworker.

If you like crazy soldering exploits, check out this PSP reverse engineering hack, where every pin of a BGA was soldered to magnet wire.

Best Product Entry: A HSDK For Ultrasound Imaging

July 2, 2017 by 33 Comments

As an entry into this year’s Best Product portion of the Hackaday Prize, [kelu124] is developing a hardware and software development kit for ultrasound imaging.

Ultrasound is one of the primary tools used in modern diagnostic medicine. Head to the doctor with abdominal pain, and you can bet you’ll be seeing the business end of an ultrasound system. While Ultrasound systems have gotten cheaper, they aren’t something everyone has in the home yet.  [kelu124] is working to change that by building a hardware and software development kit which can be used to explore ultrasound systems. This isn’t [kleu124’s] first rodeo. HSDK builds upon and simplifies Murgen, his first open source ultrasound, and an entry in the 2016 Hackaday prize. [kelu124’s] goal is to “simplify everything, making it more robust and more user-friendly”.

The system is driven by a Raspberry Pi Zero W. A custom carrier board connects the Pi to the pulser block, which sends out the ultrasonic pings, and the analog front end, which receives the reflected signals. The receiver is called Goblin, and is a custom PCB designed [kelu124] designed himself. It uses a variable gain amplifier to bring reflected ultrasound signals up out of the noise.

A system like this would be a boon both to hackers and medical professionals working in the field. Ultrasonics can do more than just imaging. You can decrease healing time with ultrasonics, or even levitate things!

The HackadayPrize2017 is Sponsored by:

Manned Multirotor Flies Again, Electric Style

July 1, 2017 by 85 Comments

You can’t keep a good hacker down. [Amazingdiyprojects] wants to build a reliable manned multirotor, and by golly, he’s doing it.  After a crash of his petrol powered design, [Amazingdiyprojects] went back to the drawing board. The new version is called chAIR, and is electric-powered.

The flying machine is lifted by 76 Multistar Elite quadcopter motors. Control is passed through 5 KK 2.1 quadcopter controllers. The KK board is a very simple controller, and we’re a bit surprised [Amazingdiyprojects] didn’t go with a newer setup. Batteries are 80x Multistar 4S 5.2Ah packs, stored below the seat. If these names sound familiar, it’s because just about every electrical part was purchased from Hobby King – an online hobby retailer.

The machine has an all up weight of 162 kg. A bit more than a single person can carry, but chAIR breaks down for easy transport.

We’re blown away by all the little details on chAIR – including the new control system. The left stick controls throttle, while right appears to control aileron/elevator and twist for the rudder control. Somewhat different from the collective/cycle controls found on conventional helicopters!

Even the battery connectors needed custom work. How do you connect 20 batteries at once? [AmazingDiyProjects] mounted XT60 connectors in a metal ring. The ring is compressed with a central screw. A quick spin with a battery-powered drill allows this new aviator to connect all his batteries at once. Is this the future of aviation, or is this guy just a bit crazy? Tell us in the comments!

Continue reading “Manned Multirotor Flies Again, Electric Style” →

An Electric Fence For Snails And Slugs

June 29, 2017 by 72 Comments

Anyone with a garden knows about doing battle with pests. Weeds, bugs, rabbits, birds — all of them try to get a bite out of our flowers and vegetables. Some of the worst are mollusks. Snails and slugs are notorious plant attackers. Tomato plants don’t stand a chance when these beasts come to town. Some folks would reach for the pesticide or even the salt, but [wheldot] had a better idea. He built an electric fence to keep these pests at bay.

Much like the electric fences used for large mammals like horses or cows, this fence is designed to deter, but not kill slugs and snails. The design is incredibly simple – two bare wires are strung around the raised garden about one centimeter apart. The wires are connected to a nine-volt battery. No boost circuit, no transistors, just nine volts across two wires. That’s all it takes to turn a slug away.

[Wheldot] didn’t come up with this hack — it’s been around in various forms for years. The nine-volt battery provides just enough current to annoy the slug or snail. The best part is that when not actively shocking a slug, the only current passing through the circuit is the whatever is passed through the wood.

Reddit user [gnichol1986] measured that at around 180 kΩ through wet wood. That means a typical 400 mAh battery would last around 34 days of continuous rain. Even in the UK it doesn’t rain that much. With a little work insulating the wires from the wood, that could be extended to the full shelf life of the battery.

You know, slugs and critters get into electronics too, so don’t forget a waterproof case to make sure your project stays slug free!

Continue reading “An Electric Fence For Snails And Slugs” →