A Remotely Controlled Kindle Page Turner

August 15, 2018 by Tom Nardi 25 Comments

One of the biggest advantages of e-readers such as the Kindle is the fact that it doesn’t weigh as much as a traditional hardcover book, much less the thousands of books it can hold in digital form. Which is especially nice if you drop the thing on your face while reading in bed. But as light and easy to use as the Kindle is, you still need to hold it in your hands and interact with it like some kind of a baby’s toy.

Looking for a way to operate the Kindle without having to go through the exhaustive effort of raising their hand, [Alex Mikes] designed and built a clip-on device that makes using Amazon’s e-reader even easier. At the press of a button, the device knocks on the edge of the screen which advances the book to the next page. Going back a page will still require you to extend your meaty digit, but that’s your own fault for standing in the way of progress.

The 3D printed case holds an Arduino and RF receiver, as well as a small servo to power the karate-chop action. There’s no battery inside, meaning the device needs to stay plugged in via a micro USB connection on the back of the case. But let’s be honest: if you’re the kind of person who has a remote-controlled Kindle, you probably aren’t leaving the house anytime soon.

To fool the Kindle into thinking a human finger is tapping the screen, the page turner’s arm has a stylus tip on the end. A channel is designed into the 3D printed arm for a wire to run from the tip to the Arduino’s ground, which triggers the capacitive screen to register a touch.

All joking aside, the idea holds promise as an assistive technology for individuals who are unable to lift an e-reader or operate its touch screen controls. With the Kindle held up in a mount, and this device clipped onto the side, anyone who can push a button (or trigger the device in whatever method they are physically capable) can read a book on their own. A simple pleasure that can come as a huge comfort to a person who may usually be dependent on others.

In the past we’ve seen physical buttons printed for touch screens, and an Arduino used to control a touch screen device. But this particular combination of physical and electrical interaction is certainly a unique way to tackle the problem without modifying the target device.

Replacement Audi Plastics Thanks To 3D Printing

August 15, 2018 by Lewin Day 39 Comments

Old cars can be fun, and as long as you drive something that was once moderately popular, mechanical parts can be easy enough to come by. Things like filters, spark plugs, idle air solenoids – they’re generally available for decades after a car is out of production as long as you know where to look. However, plastics can be much harder to come by. 20 to 30 years into a car’s lifetime, and you’ll be hard pressed to find a radio surround or vent trim in as-new condition – they’ve all long ago succumbed to the sun and air like the cracked and discoloured piece in your own car. What is a hacker to do? Bust out the 3D printer, of course!

[Stephen Kraus] has developed a series of parts for his Audi, ready to print on the average home 3D printer. There’s the triple gauge mount which fits in the radio slot for that classic tuner look, to the printed wheel caps which are sure to come in handy after you’ve lost the originals. There are even useful parts for capping off the distributor if you’re switching to a more modern ignition setup. [Stephen] also reports that his replacement shifter bushing printed in PLA has lasted over a year in normal use.

This is an excellent example of what 3D printers do best – obscure, bespoke one-off parts with complex geometries are no trouble at all, and can be easily made at home. We’ve seen this done to great effect before, too – for example with this speedometer correction gear in an old truck.

Power Generation Modules Mix And Match Wind, Water, And Hand Cranks

August 13, 2018 by Donald Papp 8 Comments

What’s great about the Power Generation Modules project headed by [Cole B] is the focus on usability and modularity. The project is a system for powering and charging small devices using any number and combination of generator modules: wind turbine, hand-crank, and water turbine so far. Power management and storage is handled by a separate unit that acts as a battery bank to store the output from up to six generators at once. There’s also a separate LED lamp module, designed to be capable of being powered directly from any of the generator modules if needed.

The hand crank is straightforward in concept, but key to usability was selecting a DC gearmotor with a gear ratio that made cranking by hand both comfortable and sustainable; too weak of a crank and it’s awkward, too hard and it’s tiring. The wind turbine has three compact vanes that turn a central shaft, but testing showed the brushless motor it uses as a generator isn’t a good match for the design; the wind turbine won’t turn well in regular wind conditions. The water turbine prototype showed great success; it consists of an epoxy-glazed, 5 inch diameter 3D printed propeller housed in a section of PVC pipe. The propeller drives a brushless motor which [Cole B] says easily outputs between eight to ten volts when testing in a small stream.

The team has plans for other generators such as solar, but this is a great start to an array of modules that can be used to power and charge small devices while off the grid. We’re happy to see them as a finalist for The Hackaday Prize; they were selected as one of the twenty projects to receive $1000 cash each in the Power Harvesting Challenge. The Human-Computer Interface Challenge is currently underway which seeks innovative ideas about how humans and computers can interface with one another, and twenty of those finalists will also receive $1000 each and be in the running for the Grand Prize of $50,000.

Ease Rover Development With These Self-Contained Track Units

August 10, 2018 by Donald Papp 2 Comments

Tracked drive systems are great, but implementation isn’t always easy. That’s what [nahueltaibo] found every time he tried to use open sourced track designs for his own rovers. The problem is that a tracked drive system is normally closely integrated with a vehicle’s chassis, mixing and matching between designs is impractical because the tracks and treads aren’t easily separated from the rest of the vehicle.

To solve this, [nahueltaibo] designed a modular, 3D printable rover track system. It contains both a motor driver and a common DC gearmotor in order to make a standalone unit that can be more easily integrated into other designs. These self-contained rover tracks don’t even have a particular “inside” or “outside”; they can be mounted on a vehicle’s left or right without any need to mirror the design. The original CAD design is shared from Fusion 360, but can also be downloaded from Thingiverse. A bit more detail is available from [nahueltaibo]’s blog, where he urges anyone who tries the design or finds it useful to share a photo or two.

3D printed tank tracks — including this one — often use a piece of filament as a hinge between track segments and sometimes slightly melted on the ends to act as a kind of rivet, which is itself a pretty good hack.

DIY Scientific Calculator Powered By Pi Zero

August 7, 2018 by Tom Nardi 25 Comments

It’s the eternal question hackers face: do you built it, or do you buy it? The low cost and high availability of electronic gadgets means we increasingly take the latter option. Especially since it often ends up that building your own version will cost more than just buying a commercial product; and that’s before you factor in the time you’ll spend working on it.

But such concerns clearly don’t phase [Andrea Cavalli]. Sure he could just buy a scientific calculator, but it wouldn’t really be his scientific calculator. Instead, he’s taking the scenic route and building his own scientific calculator from scratch. The case is 3D printed, the PCB is custom, and even the software is his own creation.

His PCB hooks right up to the GPIO pins of the internal Raspberry Pi Zero, making interfacing with the dome switch keyboard very easy. The board also holds the power management hardware for the device, including the physical power switch, USB connection for charging, and TPS79942DDCR linear regulator.

The case, including the buttons, is entirely 3D printed. At this point the buttons don’t actually have any labels on them, which presumably makes the calculator more than a little challenging to use, but no doubt [Andrea] is working on that for a later revision of the hardware. A particularly nice detail is the hatch to access the Pi’s micro SD card, making it easy to update the software or completely switch operating systems without having to take the calculator apart.

After the kernel messages scroll by, the Pi boots right into the Java calculator environment. This gives the user a fairly standard scientific calculator experience, complete with nice touches like variable highlighting. The Mario mini-game probably isn’t strictly required, but if you’re writing the code for your own calculator you can do whatever you want.

Here at Hackaday we’ve seen a calculator that got a Raspberry Pi upgrade, a classic scientific calculator emulated with an Arduino, and of course we’ve raved about the NumWorks open source graphing calculator. Even with such stiff competition, we think this project is well on its way to being one of the most impressive calculators we’ve ever come across.

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Micro-Organisms Give Up The Volts In This Biological Battery

July 27, 2018 by Donald Papp 18 Comments

Battery cells work by chemical reactions, and the fascinating Hybrid Microbial Fuel Cell design by [Josh Starnes] is no different. True, batteries don’t normally contain life, but the process coughs up useful electrons all the same; 1.7 V per cell in [Josh]’s design, to be precise. His proof of concept consists of eight cells in parallel, enough to give his cell phone a charge via a DC-DC boost converter. He says it’s not known how long this can be expected to last before the voltage drops to an unusable level, but it works!

Eight-cell, 3D printed proof of concept.

There are two complementary sides to each cell in [Josh]’s design. On the cathode side are phytoplankton; green micro algae that absorb carbon dioxide and sunlight. On the anode side are bacteria that break organic material (like food waste) into nitrates, and expel carbon dioxide. Version 2 of the design will incorporate a semi-permeable membrane between the cells that would allow oxygen and carbon dioxide to be exchanged while keeping the populations of micro-organisms separate; this would make the biological processes more complementary.

A battery consisting of 24 cells and a plumbing system to cycle and care for the algae and bacteria is the ultimate goal, and we hope [Josh] can get closer to that now that his project won a $1000 cash prize as one of the twenty finalists in the Power Harvesting Challenge portion of the Hackaday Prize. (Next up is the Human Computer Interface Challenge, just so you know.)

Watney: A Fully 3D Printed Rover Platform

July 15, 2018 by Tom Nardi 9 Comments

We’re getting to the point that seeing 3D printed parts in a project or hack isn’t as exciting as it was just a few years ago. The proliferation of low-cost desktop 3D printers means that finding a printer to squirt out a few parts for your build isn’t the adventure it once was. Gone are the days of heading to a local hackerspace or college hoping their janky Mendel felt like working that day. But all that really means is that hackers and makers now have the ability to utilize 3D printing even more. Forget printing one or two parts of your design, just print the whole thing.

That’s exactly what [Nik Ivanov] did with Watney, his fully 3D printed rover project. After lamenting that many so-called 3D printed rovers were anything but, he set out to design one that was not only made primarily of printed parts, but was robust enough to put some real work in. Over the course of several design iterations, he built a very capable all-wheel drive platform that needs only some electronics and a handful of M3 screws to leap into action.

As long as you’ve got a 3D printer big enough to handle the roughly 120mm x 190mm dimensions of this bot’s body, you’re well on the way to owning your very own video rover. [Nik] recommends printing everything in PETG, no doubt for its increased strength when it comes to things like the drive gears. Plus it’s low warp, which is really going to help when printing the top and bottom sections of the body. TPU is advised for the tires, but if you don’t have any (or your printer chokes on flexible filaments) you can just wrap the wheels with wide rubber bands.

[Nik] is using a Raspberry Pi Zero W as the brains of the operation, but the beauty of an open platform like this is that you could easily swap out the controls for something else to meet your needs. In addition to the Pi, there’s a L298N H-bridge motor controller to interface with the dual geared motors, as well as a servo to provide tilt for the SainSmart camera module.

We’ve often been surprised at just how expensive commercial robotics platforms can be, so we’re keenly interested in seeing if the availability of designs like this spur on DIY rover development. Though if you’re looking for something a little more rough and tumble, we’ve seen a 3D printed rover that looks combat-ready.

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