DIY Gimbal For The Raspberry Pi Camera

August 19, 2019 by 3 Comments

If one wants a stabilized video feed from a drone, a gimbal setup is the way to go. However, the cheaper offerings are all rather similar, suited to a certain size and type of drone. [Jean] was building a smaller craft, so set out to create his own design specifically fit for purpose.

The build begins in the CAD suite, with a series of 3D printed parts designed to link together with a pair of brushless motors to make a 2-axis set up. After printing, the gimbal arms are bolted together with the motors and the camera and IMU are installed, with everything being wired up to a GLB MiniSTorM32 brushless gimbal controller. These controllers make the process of building a gimbal easy, meaning that individual makers don’t have to go to the trouble of designing motor controller circuitry again and again.

The final result is a compact gimbal sized perfectly for the Raspberry Pi camera in [Jean]’s design. If you’re very particular about your gimbal’s performance, building your own doesn’t hurt. Video after the break.

Continue reading “DIY Gimbal For The Raspberry Pi Camera” →

Apollo’s PLSS And The Science Of Keeping Humans Alive In Space

August 19, 2019 by 13 Comments

Ever since humans came up with the bright idea to explore parts of the Earth which were significantly less hospitable to human life than the plains of Africa where humankind evolved, there’s been a constant pressure to better protect ourselves against the elements to keep our bodies comfortable. Those first tests of a new frontier required little more than a warm set of clothes. Over the course of millennia, challenging those frontiers became more and more difficult. In the modern age we set our sights on altitude and space, where a warm set of clothes won’t do much to protect you.

With the launch of Sputnik in 1957 and the heating up of the space race between the US and USSR, many firsts had to be accomplished with minimal time for testing and refinement. From developing 1945’s then state-of-the-art V-2 sounding rockets into something capable of launching people to the moon and beyond, to finding out what would be required to keep people alive in Earth orbit and on the Moon. Let’s take a look at what was required to make this technological marvel happen, and develop the Portable Life Support System — an essential component of those space suits that kept astronauts so comfortable they were able to crack jokes while standing on the surface of the Moon.

Continue reading “Apollo’s PLSS And The Science Of Keeping Humans Alive In Space” →

Warshipping: A Free Raspberry Pi In The Mail Is Not Always A Welcome Gift

August 19, 2019 by 39 Comments

Leading edge computer security is veiled in secrecy — a world where novel attacks are sprung on those who do not yet know what they need to protect against. Once certain tactics have played out within cool kids’ circles, they are introduced to the rest of the world. An IBM red team presented what they’re calling “warshipping”: sending an adversarial network to you in a box.

Companies concerned about security have learned to protect their internet-accessible points of entry. Patrolling guards know to look for potential wardrivers parked near or repeatedly circling the grounds. But some are comparatively lax about their shipping & receiving, and they are the ideal targets for warshipping.

Bypassing internet firewalls and security perimeters, attack hardware is embedded inside a shipping box and delivered by any of the common carriers. Security guards may hassle a van bristling with antennas, but they’ll wave a FedEx truck right through! The hardware can be programmed to stay dormant through screening, waiting to probe once inside the walls.

The presentation described several ways to implement such an attack. There is nothing novel about the raw hardware – Raspberry Pi, GPS receiver, cellular modems, and such are standard fare for various projects on these pages. The creative part is the software and in how they are hidden: in packing material and in innocuous looking plush toys. Or for persistence, they can be hidden in a wall mounted plaque alongside some discreet photovoltaic panels. (Editor’s note: What? No Great Seals?)

With this particular technique out in the open, we’re sure others are already in use and will be disclosed some years down the line. In the meantime, we can focus our efforts on more benign applications of similar technology, whether it is spying on our cat or finding the nearest fast food joint. The hardware is evolving as well: a Raspberry Pi actually seems rather heavyweight for this, how about a compact PCB with both an ESP32 and a cellular modem?

Via Ars Technica.

The Thermochromic Display You Didn’t Know You Needed

August 19, 2019 by 8 Comments

We love unique ways of displaying data here at Hackaday, and this ingenious thermochromic display created by [Moritz v. Sivers] more than fits the bill. Using sheets of color changing liquid crystals and careful temperature control of the plates they’re mounted on, he’s built a giant seven-segment display that can colorfully (albeit somewhat slowly) show the current temperature and humidity.

The sheets of temperature sensitive liquid crystals are a bit like flattened out Mood Rings; they starts out black, but as heat is applied, their color cycles through vibrant reds, greens, and blues. The sheets are perhaps best known as the sort of vaguely scientific toys you might see in a museum gift shop, but here [Moritz] has put their unique properties to practical use.

To achieve the effect, he first cut each segment out of copper. The crystal sheets were applied to the segments, thanks to their handy self-stick backing, and the excess was carefully trimmed away. Each segment was then mounted to a TES1-12704 Peltier module by way of thermally conductive epoxy. TB6612FNG motor controllers and a bevy of Arduino Nano’s are used to control the Peltier modules, raising and lowering their temperature as necessary to get the desired effect.

You can see the final result in the video after the break. It’s easily one of the most attractive variations on the classic seven-segment display we’ve ever seen. In fact, we’d go as far as to say it could pass for an art installation. The idea of a device that shows the current temperature by heating itself up certainly has a thoughtful aspect to it.

This actually isn’t the first display we’ve seen that utilized this concept, though it’s by far the largest. Back in 2014 we featured a small flexible display that used nichrome wires to “print” digits on a sheet of liquid crystals.

Continue reading “The Thermochromic Display You Didn’t Know You Needed” →

MIDI Controller In A Concertina Looks Sea Shanty-Ready

August 18, 2019 by 5 Comments

Did you know that the English concertina, that hand-pumped bellows instrument favored by sailors both legitimate and piratical in the Age of Sail, was invented by none other than [Sir Charles Wheatstone]? We didn’t, but [Dave Ehnebuske] knew that the venerable English gentleman was tickling the keys of his instrument nearly two decades before experimenting with the bridge circuit that would bear his name.

This, however, is not the reason [Dave] built a MIDI controller in the form of an English concertina. That has more to do with the fact that he already knows how to play one, they’re relatively easy to build, and it’s a great form factor for a MIDI controller. A real concertina has a series of reeds that vibrate as air from the hand bellows is directed over them by valves controlled by a forest of keys. [Dave]’s controller apes that form, with two wind boxes made from laser-cut plywood connected by a bellows made from cardboard, Tyvek, and nylon fabric. The keys are non-clicky Cherry MX-types that are scanned by a Bluefeather microcontroller. To provide some control over expression, [Dave] included a pressure sensor, which alters the volume of the notes played depending on how hard he pushes the bellows. The controller talks MIDI over Bluetooth, and you can hear it in action below.

We’ve seen MIDI controllers in just about everything, from a pair of skate shoes to a fidget spinner. But this is the first time we’ve seen one done up like this. Great job, [Dave]!

Continue reading “MIDI Controller In A Concertina Looks Sea Shanty-Ready” →

Exploring The Science Behind Dirty Air Filters

August 18, 2019 by 34 Comments

Obviously, if the air filters in your home HVAC system are dirty, you should change them. But exactly how dirty is dirty? [Tim Rightnour] had heard it said that if you didn’t change your filter every month or so, it could have a detrimental effect on the system’s energy consumption. Thinking that sounded suspiciously like a rumor Big Filter™ would spread to bump up their sales, he decided to collect his own data and see if there was any truth to it.

There’s a number of ways you could tackle a project like this, but [Tim] wanted to keep it relatively simple. A pressure sensor on either side of the filter should tell him how much it’s restricting the airflow, and recording the wattage of the ventilation fan would give him an idea on roughly how hard the system was working.

Now [Tim] could have got this all set up and ran it for a couple months to see the values gradually change…but who’s got time for all that? Instead, he recorded data while he switched between a clean filter, a mildly dirty one, and one that should have been taken out back and shot. Each one got 10 minutes in the system to make its impression on the sensors, including a run with no filter at all to serve as a baseline.

The findings were somewhat surprising. While there was a sizable drop in airflow when the dirty filter was installed, [Tim] found the difference between the clean filter and mildly soiled filter was almost negligible. This would seem to indicate that there’s little value in preemptively changing your filter. Counter-intuitively, he also found that the energy consumption of the ventilation fan actually dropped by nearly 50 watts when the dirty filter was installed. So much for a clean filter keeping your energy bill lower.

With today’s cheap sensors and virtually infinite storage space to hold the data from them, we’re seeing hackers find all kinds of interesting trends in everyday life. While we don’t think your air filters are spying on you, we can’t say the same for those fancy new water meters.

Hackaday Links Column Banner

Hackaday Links: August 18, 2019

August 18, 2019 by 28 Comments

To the surprise of nobody with the slightest bit of technical intuition or just plain common sense, the world’s first solar roadway has proven to be a complete failure. The road, covering one lane and stretching all of 1,000 meters across the Normandy countryside, was installed in 2016 to great fanfare and with the goal of powering the streetlights in the town of Tourouvre. It didn’t even come close, producing less than half of its predicted power, due in part to the accumulation of leaves on the road every fall and the fact that Normandy only enjoys about 44 days of strong sunshine per year. Who could have foreseen such a thing? Dave Jones at EEVBlog has been all over the solar freakin’ roadways fiasco for years, and he’s predictably tickled pink by this announcement.

I’m not going to admit to being the kid in grade school who got bored in class and regularly filled pages of my notebook with all the binary numbers between 0 and wherever I ran out of room – or got caught. But this entirely mechanical binary number trainer really resonates with me nonetheless. @MattBlaze came up with the 3D-printed widget and showed it off at DEF CON 27. Each two-sided card has an arm that flops down and overlaps onto the more significant bit card to the left, which acts as a carry flag. It clearly needs a little tune-up, but the idea is great and something like this would be a fun way to teach kids about binary numbers. And save notebook paper.

Is that a robot in your running shorts or are you just sporting an assistive exosuit? In yet another example of how exoskeletons are becoming mainstream, researchers at Harvard have developed a soft “exoshort” to assist walkers and runners. These are not a hard exoskeleton in the traditional way; rather, these are basically running short with Bowden cable actuators added to them. Servos pull the cables when the thigh muscles contract, adding to their force and acting as an aid to the user whether walking or running. In tests the exoshorts resulted in a 9% decrease in the amount of effort needed to walk; that might not sound like much, but a soldier walking 9% further on the same number of input calories or carrying 9% more load could be a big deal.

In the “Running Afoul of the FCC” department, we found two stories of interest. The first involves Jimmy Kimmel’s misuse of the Emergency Alert System tones in an October 2018 skit. The stunt resulted in a $395,000 fine for ABC, as well as hefty fines for two other shows that managed to include the distinctive EAS tones in their broadcasts, showing that the FCC takes very seriously indeed the integrity of a system designed to warn people of their approaching doom.

The second story from the regulatory world is of a land mobile radio company in New Jersey slapped with a cease and desist order by the FCC for programming mobile radios to use the wrong frequency. The story (via r/amateurradio) came to light when someone reported interference from a car service’s mobile radios; subsequent investigation showed that someone had programmed the radios to transmit on 154.8025 MHz, which is 5 MHz below the service’s assigned frequency. It’s pretty clear that the tech who programmed the radio either fat-fingered it or misread a “9” as a “4”, and it’s likely that there was no criminal intent. The FCC probably realized this and didn’t levy a fine, but they did send a message loud and clear, not only to the radio vendor but to anyone looking to work frequencies they’re not licensed for.