Hacker Abroad: Cellphone Repair In Huaqiangbei And A Huge Meetup At Seeed

March 25, 2019 by 13 Comments

Shenzhen, China is the home of the legendary electronics markets of Huaqiangbei. Friday was my first full day in the city, having spent the previous three days in Shanghai. We got a little bit of a late start as our flight didn’t arrive until after 1 am and we stayed at the first night at an airport hotel. We met up with Scotty Allen for an amazing meal followed by a very unique experience in the electronics markets, not just seeing the items, but meeting the booth owners who showed off some of their secrets.

The day was capped off by an absolutely packed meetup at X.factory, the collaborative creative space run by Seeed Studio. They lined up a half dozen hardware talks that were quite excellent, and there was a ton of hardware being demonstrated as the night progressed. They had to kick us out or we’d have stayed all night!

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Show Your Skills With A Bootable CV

March 23, 2019 by 10 Comments

It’s a thankless task, searching for a job. You send off your CV, or resume, and it joins a thousand other destined for the round file. What on earth can you do to make your career stand out, and catch the eye of the recruiter?

Your bootable CV isn't eye-catching if the recruiter uses GitHub to view the PDF.
Your bootable CV isn’t eye-catching if the recruiter uses GitHub to view the PDF.

If you are [Pablo Jiménez Mateo], the answer is straightforward enough. Simply combine the document as a PDF with an x86 bootloader, to make a readable document that will also boot an x86 computer system. He can do this relatively easily by prepending the bootloader file to the PDF, as long as the “%PDF” header of the CV remains within the first 1024 bytes it will remain a readable document. Which it does, though as our GitHub screenshot shows, not in all PDF readers.

A bootable PDF is pretty cool and we have to salute his effort in getting it in front of us in the hope of  career boost, but it would be fair to admit that it’s a trick that has been done before. So it’s time to turn attention to the bootloader itself, whose code comes in the form of an extremely well-commented assembly file that loads some sprites and a border to a VGA screen that looks as though it might be the first room in a top-down adventure game. Through the code we can gain an appreciation of just how simple a bootloader can be, and that in itself makes this project worth a second look.

If writing your own bootloader interests you, that’s certainly a subject we’ve covered in the past. It’s possible to make bootable images very small indeed, even down to fitting in a Tweet.

Downdraft Table Inhales Dust, Not Cash

March 14, 2019 by 15 Comments

We always look forward to the builds [MakerMan] sends in, and it’s not just because we dig his choices in royalty free music (though it helps). He always manages to put together his projects with a minimum of fuss, and perhaps more importantly, a minimum of funds. His builds use salvaged components, easily sourced materials, and common tools. Watching him work invariably makes us realize that we tend to overthink our own projects.

In his latest video, [MakerMan] was tasked with building a downdraft table for a local factory that makes jewelry boxes. By sucking air through a series of holes in the table’s surface, sawdust created while the workers are building the boxes will automatically be removed from the workspace. Even if you aren’t in the jewelry box making business, any task which produces fine particles (such as sanding) could benefit from such a setup. You probably won’t need a downdraft table quite as large as the one he builds, but the principles will be the same if you get inspired to build a somewhat smaller version.

The build starts with sheets of MDF, which get cut, glued, and screwed together to make the basic tabletop shape. To this, [MakerMan] attaches a welded steel frame which will give it the strength MDF itself lacks. With careful measurement, lines are plotted across the top of the MDF sheet and all the holes are drilled with a simple hand drill; no fancy CNC here.

With the table doing its best colander impression, [MakerMan] adds an air box to the bottom which is similarly made of thin MDF sheets. All of the joints are sealed up with caulk, because at this point you want things to be as air tight as possible. A large blower is attached to the bottom, which gets piped to a dust collection system that’s made of a garbage can and…you guessed it, more MDF.

Watching [MakerMan] turn what’s often literal trash into a functional build never gets old. We’ve seen him create everything from a gorgeous origami chandelier to a very impressive diode laser cutter using little more than scrap parts and hand tools, and we can’t wait to see what he comes up with next.

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Our Right To Repair Depends On A Minimally Viable Laptop

March 7, 2019 by 142 Comments

It’s never been harder to repair your electronics. When the keyboard in your shiny new MacBook dies, you’ll have to send it to a Genius. When the battery in your iPhone dies, you’ll have to break out the pentalobe screwdrivers. Your technology does not respect your freedom, and this is true all the way down to the source code: the Library of Congress is thankfully chipping away at the DMCA in an effort that serves the Right to Repair movement, but still problems remain.

The ability — or rather, right — to repair will inevitably mean using electronics longer, and keeping them out of the garbage. That’s less e-waste, but it’s also older, potentially slower and less powerful portable workstations. This is the question: how long should you keep your electronics running? When do you start getting into the false economy of repairing something just because you can? What is the minimally viable laptop?

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R/C Whirlygig Is Terrifyingly Unstable

February 6, 2019 by 10 Comments

In the days during and immediately after World War II, aerospace research was a forefront consideration for national security. All manner of wild designs were explored as nation states attempted to gain the upper hand in the struggle for survival. The Hiller Hornet was one such craft built during this time – a helicopter which drove the rotor through tip-mounted ramjets. Unsurprisingly, this configuration had plenty of drawbacks which prevented it from ever reaching full production. The team at [FliteTest] had a soft spot for the craft, however, and used it to inspire their latest radio controlled experiment.

Initial experiments consisted of a modified foam wing from a model seaplane, with two left wings facing opposite directions, and joined in the middle. Two motors and props were fitted to the wings to provide rotational motion. After some initial vibration issues were solved, the improvised craft generated barely enough lift to get off the ground. Other problems were faced with centripetal forces tearing the propellers off the wing due to the high rotational speeds involved.

A second attempt started from scratch, with a four wing setup being used, with much higher camber, with the intention to generate more lift with a more aggressive airfoil, allowing rotational speeds to be decreased. The craft was capable of getting off the ground, but instabilities likened to the pendulum rocket fallacy prevented any major gain in altitude.

We’d love to see a redesign to solve some of the issues and allow the craft to sail higher into the air. If you think you know the solution to the whirly bird’s dynamic problems, be sure to let us know in the comments. It should be possible, as we’ve seen successful designs inspired by maple seeds before. Video after the break.

[Thanks to Baldpower for the tip!]

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The WiFi Phone That Respects Your Right To Repair

February 6, 2019 by 49 Comments

Phones are getting increasingly more complex, more difficult to repair, and phone manufacturers don’t like you tinkering with their stuff. It’s a portable version of a John Deere tractor in your pocket, and Apple doesn’t want you replacing a battery by yourself. What if there was a phone that respected your freedom? That’s the idea behind the WiPhone, and soon it’s going to be be a crowdfunding campaign. Yes, you will soon be able to buy a phone that respects your freedom.

We took a look at the WiPhone a few months ago, and the idea was solid: make a simple, cheap, handheld device based on the ESP32 WiFi/Bluetooth wonder microcontroller. There are a few other various bits of electronic ephemera for scanning the buttons, an audio codec, and a speaker driver, but the basics of the build are just an LCD and ESP32. The entire idea of this phone is to make calls through WiFi, and given the state of VoIP, it’s a marketable product.

Astute readers may notice that the WiPhone doesn’t have a cellular modem. Yes, this is true, but putting a baseband in a small, low-volume project is incredibly hard. You’re limited to 2G if you don’t want to deal with Broadcom or Qualcomm, and they’re not going to be interested in you if you’re not moving a hundred thousand units, anyway. Also, you’ve got service plans to deal with, multi-country radios, and you’re probably next to a trusted WiFi network right now, anyway.

The WiPhone is designed to be hackable, with daughter boards that turn it into a rainbow or RC car, and easy to assemble. It’s also going to be a crowdfunding campaign at the end of the month. If you want a phone that respects your right to repair, this is the project to look at, even if you don’t need a cellular modem all the time.

Portable Ham Antenna Gets A Workout

February 1, 2019 by 13 Comments

Ham radio isn’t just one hobby. It is a bunch of hobbies ranging from chatting to building things, bouncing signals off the moon, and lots of things in between. Some of these specialties, such as supporting disaster relief or putting odd locations “on the air”, require portable operation. To encourage disaster readiness, hams participate in Field Days which is a type of contest that encourages simulated emergency conditions. So how do you erect an antenna when you just have a few hours to set up a temporary station? [KB9VBR] shows how he and his friend used a Chameleon Emcomm III portable HF antenna for Winter Field Day. You can see the video review, below.

Unlike some portable antennas, this one is almost 100 feet of wire (73 feet of radiator and a 25 foot counterpoise). The entire affair is meant to be put up and taken down repeatedly.

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