Tacking Against The Sun: Flying A Batteryless Solar RC Plane Is Almost Like Sailing

October 7, 2019 by Danie Conradie 28 Comments

Flying on the power of the sun is definitely not a new idea, but it usually involves a battery between the solar panels and the propulsion system. [ukanduit] decided to lose the battery completely and control the speed of the motor with the output of the solar panels. This leads to some interesting flying characteristics, almost akin to sailing.

When a load tries to draw more current than a solar panel can provide, its output falls dramatically, so [ukanduit] had to take this into account. Using a ATTiny85, he built a MPPT (Maximum Power Point Tracker) unit that connects between the RC receiver and the motor speed controller. It monitors the output of the panels and modulates the speed of the motor accordingly, while ensuring that there is always enough power to run the servos and receiver. The airframe (named the Solar Bear) is a small lightweight flying wing, with a balsa and carbon fibre frame covered with clear film, with the solar cells housed inside the wing. Since the thrust of the motor is directly proportional to how much sunlight hits the top of wings, it requires the pilot to “tack” against the sun and use momentum to quickly get through turns before orienting into the sun again.

If you want to build your own controller, the schematics and software is up on RC Groups. Check out the Solar Bear in action, flown here by [AJWoods].

Continue reading “Tacking Against The Sun: Flying A Batteryless Solar RC Plane Is Almost Like Sailing” →

Dry Your Clothes In One Minute Or Less

October 7, 2019 by Sharon Lin 39 Comments

If you’re like most people, then washing clothes is probably a huge pain for you. Figuring out the odd number of minutes necessary to run a wash and dry cycle, trying desperately not to end up with clothes that are still wet, and worst of all having to wait so long for your clothes to be clean can be a real hassle.

One team of inventors decided to build Eleven, a dryer that dries and sanitizes clothes in a minute or less. As explained in their demo video, clothes are placed around the center tube and dried by the airflow initiated by Eleven. Fragrance and ozone is injected to prevent bacteria from causing bad smells.

The team experimented with ultrasonics and microwave-vacuum system, and ultimately decided to use a method that controls the flow of air within the fabric. A steam generator sprays the clothes with a disinfectant while a filter quarantines the chemicals to a receptacle within the device.

They also installed sensors to monitor the performance of the machine remotely, allowing users to track their clothes and the health of the machine even when they aren’t home. Something we’ve previously seen done in the DIY space.

It might not be the futuristic heat-free clothes dryer we were promised, but Eleven certainly looks like a step in the right direction.

Ask Hackaday: What’s The Perfect Hacker Smart Watch?

October 7, 2019 by Lewin Day 76 Comments

Since Dick Tracy all the way back in ’46, smart watches have captured the public imagination. After several false starts, the technology has gone through a renaissance in the last 10 years or so. For the average consumer, there’s been a proliferation of hardware in the marketplace, with scores of different models to choose from. For the hackers, however, pickings are a little more slim. So what is the best smart watch for the tinkerers among us? Continue reading “Ask Hackaday: What’s The Perfect Hacker Smart Watch?” →

Designing Sci-Fi Hack Chat

October 7, 2019 by Dan Maloney 9 Comments

Join us on Wednesday, October 9 at noon Pacific for the Designing Sci-Fi Hack Chat with Seth Molson!

We all know the feeling of watching a movie set in a galaxy far, far away and seeing something that makes us say, “That’s not realistic at all!” The irony of watching human actors dressed up as alien creatures prancing across a fantasy landscape and expecting realism is lost on us as we willingly suspend disbelief in order to get into the story; seeing something in that artificial world that looks cheesy or goofy can shock you out of that state and ruin the compact between filmmaker and audience.

Perhaps nowhere do things get riskier for filmmakers than the design of the user interfaces of sci-fi and fantasy sets. Be they the control panels of spacecraft, consoles for futuristic computers, or even simply the screens of phones that are yet to be, sci-fi UI design can make or break a movie. The job of designing a sci-fi set used to be as simple as wiring up strings of blinkenlights; now, the job falls to a dedicated artist called a Playback Designer who can create something that looks fresh and new but still plausible to audiences used to interacting with technology that earlier generations couldn’t have dreamed of.

Seth Molson is one such artist, and you’ve probably seen some of his work on shows such as Timeless, Stargate Universe, and recently Netflix’s reboot of Lost in Space. When tasked to deliver control panels for spacecraft and systems that exist only in a writer’s mind, Seth sits down with graphics and animation software to make it happen.

Join us as we take a look behind the scenes with Seth and find out exactly what it’s like to be a Playback Designer. Find out what Seth’s toolchain looks like, how he interacts with the rest of the production design crew to come up with a consistent and believable look and feel for interfaces, and what it’s like to design futures that only exist — for now — in someone’s imagination.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, October 9 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Raspberry Pi Ham Radio Remote Reviewed

October 7, 2019 by Al Williams 18 Comments

One problem with ham radio these days is that most hams live where you can’t put a big old antenna up due to city laws and homeowner covenants. If you’re just working local stations on VHF or UHF, that might not be a big problem. But for HF usage, using a low profile antenna is a big deal. However, most modern radios can operate remotely. Well-known ham radio company MFJ now has the RigPi Station Server and [Ham Radio DX] has an early version and did a review.

As the name implies, the box contains a Raspberry Pi. There’s also an audio interface. The idea is to consolidate rig control along with other station control (such as rotators) along with feeding audio back and forth to the radio. It also sends Morse code keying to the radio. The idea is that this box will put your radio on the network so that you operate it using a web browser on a PC or a mobile device.

According to MFJ, you can operate voice, Morse code, or digital modes easily and remotely. The box uses open source software that can control over 200 different radios and 30 rotors. Of course, you could build all this yourself and use the same open source software, but it is nicely packaged. [Ham Radio DX] says you don’t need to know much about the Pi or Linux to use the box, although clearly you can get into Linux and use the normal applications if you’re so inclined.

Even if you don’t want to transmit, we could see a set up like this being used for remote monitoring. We’d like to see a companion box for the remote end that had the audio hardware, a keyer, and perhaps a knob to act as a remote control of sorts. Of course, you could probably figure out how to do that yourself. We wonder if some ham clubs might start offering a remote radio via an interface like this — we’ve seen it done before, but not well.

Your $50 radio probably isn’t going to work with this, and if you use FT8, you could argue you don’t need to be there anyway.

Continue reading “Raspberry Pi Ham Radio Remote Reviewed” →

Better Battery Management Through Chemistry

October 7, 2019 by Bob Baddeley 33 Comments

The lead-acid rechargeable battery is a not-quite-modern marvel. Super reliable and easy to use, charging it is just a matter of applying a fixed voltage to it and waiting a while; eventually the battery is charged and stays topped off, and that’s it. Their ease is countered by their size, weight, energy density, and toxic materials.

The lithium battery is the new hotness, but their high energy density means a pretty small package that can get very angry and dangerous when mishandled. Academics have been searching for safer batteries, better charge management systems, and longer lasting battery formulations that can be recharged thousands of times, and a recent publication is generating a lot of excitement about it.

Consider the requirements for a battery cell in an electric car:

High energy density (Lots of power stored in a small size)
Quick charge ability
High discharge ability
MANY recharge cycles
Low self-discharge
Safe

Lithium ion batteries are the best option we have right now, but there are a variety of Li-ion chemistries, and depending on the expected use and balancing and charging, different chemistries can be optimized for different performance characteristics. There’s no perfect battery yet, and conflicting requirements mean that the battery market will likely always have some options.

Continue reading “Better Battery Management Through Chemistry” →

Make “Wireless” Earbuds Truly Wireless

October 7, 2019 by Kristina Panos 9 Comments

[Don] bought some off-brand Bluetooth earbuds online that actually sound pretty good. But while it’s true that they don’t require wires for listening to tunes, the little storage/charging box they sleep in definitely has a micro USB port around back. Ergo, they are not truly wireless. So [Don] took it upon himself to finish what the manufacturer started. Because it’s 2019, and words have meaning.

Finally, he had a use for that Qi charger he’s had lying around since the Galaxy S5 era. [Don] pried the earbud case open with a guitar pick and found a nicely laid-out charging circuit board without any black goop.

Once he located ground and Vcc pads, it was just a matter of performing a bit of surgery on the coil’s pins so he could solder wires there instead. Miraculously, the Qi coil fit perfectly inside the bottom of the case and the plastic is thin enough that it doesn’t interfere with the charging.

Want to try it for yourself? [Don]’s done an excellent job of documenting this hack, with clear pictures of every step. Soon you’ll be able to rid yourself of all those pesky USB cables.

Of course, [Don] still has to plug the charging base into the wall. If he ever wanted to add another level of wireless, he could always retrofit the base coil into his laptop.