Hackaday Links: July 12, 2020

July 12, 2020 by Dan Maloney 30 Comments

Based in the US as Hackaday is, it’s easy to overload the news with stories from home. That’s particularly true with dark tales of the expanding surveillance state, which seem to just get worse here on a daily basis. So we’re not exactly sure how we feel to share not one but two international stories of a dystopian bent; one the one hand, pleased that it’s not us for a change, but on the other, sad to see the trend toward less freedom and more monitoring spreading.

The first story comes from Mexico, where apparently everything our community does will soon be illegal. We couch that statement because the analysis is based on Google translations of reports from Mexico, possibly masking the linguistic nuances that undergird legislative prose. So we did some digging and it indeed appears that the Mexican Senate approved a package of reforms to existing federal copyright laws that will make it illegal to do things like installing a non-OEM operating system on a PC, or to use non-branded ink cartridges in a printer. Reverse engineering ROMs will be right out too, making any meaningful security research illegal. There appear to be exceptions to the law, but those are mostly to the benefit of the Mexican government for “national security purposes.” It’ll be a sad day indeed for Mexican hackers if this law is passed.

The other story comes from Germany, where a proposed law would grant sweeping surveillance powers to 19 state intelligence bodies. The law would require ISPs to install hardware in their data centers that would allow law enforcement to receive data and potentially modify it before sending it on to where it was supposed to go. So German Internet users can look forward to state-sponsored man-in-the-middle attacks and trojan injections if this thing passes.

OK, time for a palate cleanser: take an hour to watch a time-lapse of the last decade of activity of our star. NASA put the film together from data sent back by the Solar Dynamics Observatory, a satellite that has been keeping an eye on the Sun from geosynchronous orbit since 2010. Each frame of the film is one hour of solar activity, which may sound like it would be boring to watch, but it’s actually quite interesting and very relaxing. There are exciting moments, too, like enormous solar eruptions and the beautiful but somehow terrifying lunar transits. More terrifying still is a massive coronal mass ejection (CME) captured in June 2011. A more subtle but fascinating phenomenon is the gradual decrease in the number of sunspots over the decade as the Sun goes through its normal eleven-year cycle.

You’ll recall that as a public service to our more gear-headed readers that we recently covered the recall of automotive jack stands sold at Harbor Freight, purveyor of discount tools in the USA. Parts for the jack stands in question had been cast with a degraded mold, making the pawls liable to kick out under load and drop the vehicle, with potentially catastrophic results for anyone working beneath. To their credit, Harbor Freight responded immediately and replaced tons of stands with a new version. But now, Harbor Freight is forced to recall the replacement stands as well, due to a welding error. It’s an embarrassment, to be sure, but to make it as right as possible, Harbor Freight is now accepting any of their brand jack stands for refund or store credit.

And finally, if you thought that the experience of buying a new car couldn’t be any more miserable, wait till you have to pay to use the windshield wipers. Exaggeration? Perhaps only slightly, now that BMW “is planning to move some features of its new cars to a subscription model.” Plans like that are common enough as cars get increasingly complex infotainment systems, or with vehicles like Teslas which can be upgraded remotely. But BMW is actually planning on making options such as heated seats and adaptive cruise control available only by subscription — try it out for a month and if you like it, pay to keep them on for a year. It would aggravate us to no end knowing that the hardware supporting these features had already been installed and were just being held ransom by software. Sounds like a perfect job for a hacker — just not one in Mexico.

Slothbot Lives Up To Its Name

July 5, 2020 by Danie Conradie 5 Comments

For moving about in the real world, robots can crawl along the ground or take to the sky. Both options have disadvantages, with obstacles being a problem on the ground and flying being very energy intensive. What we don’t often see are robots that move along aerial cables, which can offer the best of both worlds for certain use cases. Taking inspiration from a sloth’s slow and efficient movement through the trees, researchers from Georgia Tech created a robot to crawl slowly along a cable network and monitor the world around it, and of course named it Slothbot.

Slothbot trades speed for efficiency, letting it operate for very long periods on solar power alone. It does require the set up and maintenance of a cable network, but that brings the advantage of no obstacles, and the ability to stop and recharge. To us the most interesting feature is the cable switching mechanism, that allows it to navigate its way along a web of interconnected cables.

Ring gears with a section removed hold the upper part of the pulley mechanism, but can rotate it’s opening to the left or right to allow an interconnecting cable to pass through, The body is in two pieces, with an actuated hinge in the middle to allow it to turn onto a different cable section. Each section of the body also has a powered wheel which pushes up against the cable and moves the robot along slowly. Not surprisingly, researchers say that making the cable switching mechanism reliable is the biggest challenge. It does look like the current design would not work well with thicker cable joints. Watch the video after the break for a better look at the mechanism Continue reading “Slothbot Lives Up To Its Name” →

Mini Library For Kids Gets Blinky Lights And Solar Upgrade

June 28, 2020 by Donald Papp 1 Comment

Reading is big in Québec, and [pepelepoisson]’s young children have access to a free mini library nook that had seen better days and was in dire need of maintenance and refurbishing. In the process of repairing and repainting the little outdoor book nook, he took the opportunity to install a few experimental upgrades (link in French, English translation here.)

The mini library pods are called Croque-Livres, part of a program of free little book nooks for children across Québec (the name is a bit tricky to translate into English, but think of it as “snack shack, but for books” because books are things to be happily devoured.)

After sanding and repairs and a few coats of new paint, the Croque-Livres was enhanced with a strip of WS2812B LEDs, rechargeable battery with solar panel, magnet and reed switch as door sensor, and a 3.3 V Arduino to drive it all. [pepelepoisson]’s GitHub repository for the project contains the code and CAD files for the 3D printed pieces.

The WS2812B LED strip technically requires 5 V, but as [pepelepoisson] found in his earlier project Stecchino, the LED strip works fine when driven directly from a 3.7 V lithium-polymer cell. It’s not until around 3 V that it starts to get unreliable, so a single 3.7 V cell powers everything nicely.

When the door is opened, the LED strip lights up with a brief animation, then displays the battery voltage as a bar graph. After that, the number of times the door as been opened is shown on the LED strip in binary. It’s highly visual, interactive, and there’s even a small cheat sheet explaining how binary works for anyone interested in translating the light pattern into a number. How well does it all hold up? So far so good, but it’s an experiment that doesn’t interfere at all with the operation of the little box, so it’s all good fun.

Charging Pad Flips For Solar Power

April 3, 2020 by Lewin Day 10 Comments

Charging pads are now a common, popular way to charge small devices. They have the benefit of reducing wear on connectors and being easier to use. [bcschmi6] decided to build a solar powered charging pad, which should come in handy when out and about.

The build uses a 3 W square solar panel, hooked up to an Adafruit solar charging board. This charges a pair of 18650 lithium batteries. The batteries only put out a maximum of 4.2 V, so they’re hooked up to a boost converter to get the output a little higher, up to 5.2 V. The output of the boost converter is then hooked up to a charging pad harvested from an Anker charger, and it’s all wrapped up in a tidy 3D printed frame.

We imagine the device would be great for camping. It could be left charging in the sun during the day, before being flipped over and used as a charging pad at night. It would be easy to build a bigger version for charging several phones at once, too. If you want to build your own charging coils, that’s a thing, too. And if you’ve got your own solar project cooking up as we head into summer, be sure to let us know!

Microbatteries On The Grid

March 27, 2020 by Bryan Cockfield 35 Comments

Not everybody has $6500 to toss into a Tesla Powerwall (and that’s a low estimate), but if you want the benefits of battery storage for your house, [Matt]’s modular “microbattery” storage system might be right up your alley. With a build-as-you-go model, virtually any battery can be placed on the grid in order to start storing power from a small solar installation or other power source.

The system works how any other battery installation would work. When demand is high, a series of microinverters turn on and deliver power to the grid. When demand is low, the batteries get charged. The major difference between this setup and a consumer-grade system is that this system is highly modular and each module is networked together to improve the efficiency of the overall system. Its all tied together with a Raspberry Pi that manages the entire setup.

While all of the software is available to set this up, it should go without saying that working with mains power is dangerous, besides the fact that you’ll need inverters capable of matching phase angle with the grid, a meter that handles reverse power flow, a power company that is willing to take the power, and a number of building code statutes to appease. If you don’t have all that together, you might want to go off-grid instead.

Solar Panel Keeps Car Battery Topped Off Through OBD-II Port

March 10, 2020 by Dan Maloney 47 Comments

Up until the 1980s or so, a mechanic could check for shorts in a car’s electrical system by looking for sparks while removing the battery terminal with everything turned off in the car. That stopped being possible when cars started getting always-on devices, and as [Kerry Wong] learned, these phantom loads can leave one stranded with a dead battery at the airport after returning from a long trip.

[Kerry]’s solution is simple: a solar trickle charger. Such devices are readily available commercially, of course, and generally consist of a small photovoltaic array that sits on the dashboard and a plug for the lighter socket. But as [Kerry] points out in the video below, most newer model cars no longer have lighter sockets that are wired to work without the ignition being on. So he chose to connect his solar panel directly to the OBD-II port, the spec for which calls for an always-on, fused circuit connected directly to the positive terminal of the vehicle battery. He had to hack together an adapter for the panel’s lighter plug, the insides of which are more than a little scary, and for good measure, he added a Schottky diode to prevent battery discharge through the panel. Even the weak winter sun provides 150 mA or so of trickle charge, and [Kerry] can rest assured his ride will be ready at the end of his trip.

We used to seeing [Kerry] tear down test gear and analyze unusual devices, along with the odd post mortem on nearly catastrophic failures. We’re glad nothing burst into flames with this one.

Continue reading “Solar Panel Keeps Car Battery Topped Off Through OBD-II Port” →

Laser Etches Solar Absorbing Material

February 6, 2020 by Al Williams 19 Comments

Having a laser cutter these days isn’t a big deal. But [Chunlei Guo], a professor at the University of Rochester, has a powerful femto-second pulse laser and used it to create what might be the perfect solar absorber. You can see a video about the work, below.

It stands to reason that white materials reflect most light and therefore absorb less energy than black materials — this is part of what makes a radiometer work. Tungsten, in particular, is a good metal for absorbing solar power, but this new laser treatment — which builds nanostructures on the surface of the metal — increases efficiency by 130% compared to untreated tungsten.

Continue reading “Laser Etches Solar Absorbing Material” →