Homebrewed Voice Assistant Keeps An Eye On Air Quality

Voice assistants are now available from a wide variety of companies, however, [7402] didn’t like the idea of these devices sending data off to the cloud for potentially-nefarious purposes. Thus, the goal became to build a home voice assistant that worked entirely offline, and that’s precisely what [7402] achieved.

The system had limited goals compared to commercial competitors. [7402] was more than happy to deal with a limited vocabulary of understanding as a trade off for privacy. It’s all built around a Raspberry Pi Zero, which runs the Julius speech recognition library. Ultrasonic sensors are used to only activate the device when a person leans in and directly addresses the system.

Capabilities include reporting on the weather, switching light on and off, and advising users of air quality readings from the local authorities.  Feedback to the user is via text-to-speech as well as flashing LEDs. The latter are used to create a quirky, retro “thinking” animation to indicate the system is processing, and has indeed heard a spoken command.

It’s a neat build, and one that covers most of the good things that commercial cloud devices are capable of anyway. As a bonus, no smartphone apps are required, nor will private companies impact the system’s functionality as it relies on no external servers to operate.

We’ve seen similar builds before too, such as this GlaDOS-themed voice assistant. Video after the break.

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This Week In Security: The Battle Against Ransomware, Unicode, Discourse, And Shrootless

We talk about ransomware gangs quite a bit, but there’s another shadowy, loose collection of actors in that arena. Emsisoft sheds a bit of light on the network of researchers and law enforcement that are working behind the scenes to frustrate ransomware campaigns.

Darkside is an interesting case study. This is the group that made worldwide headlines by hitting the Colonial Pipeline, shutting it down for six days. What you might not realize is that the Darkside ransomware software had a weakness in its encryption algorithms, from mid December 2020 through January 12, 2021. Interestingly, Bitdefender released a decryptor on January 11. I haven’t found confirmation, but the timing seems to indicate that the release of the decryptor triggered Darkside to look for and fix the flaw in their encryption. (Alternatively, it’s possible that it was released in response the fix, and time zones are skewing the dates.)

Emsisoft is very careful not to tip their hand when they’ve found a vulnerability in a ransomware. Instead, they have a network of law enforcement and security professionals that they share information with. This came in handy again when the Darkside group was spun back up, under the name BlackMatter.

Not long after the campaign was started again, a similar vulnerability was reintroduced in the encryption code. The ransomware’s hidden site, used for negotiating payment for decryption, seems to have had a vulnerability that Emsisoft was able to use to keep track of victims. Since they had a working decryptor, they were able to reach out directly, and provide victims with decryption tools.

This changed when the link to BlackMatter’s portal leaked on Twitter. It seems like many people hold ransomware gangs in less-than-high regard, and took the opportunity to inform BlackMatter of this fact, using that portal. In response, BlackMatter took down that portal site, cutting off Emsisoft’s line of information. Since then, the encryption vulnerability has been fixed, Emisoft can’t listen in on BlackMatter anymore, and they released the story to encourage BlackMatter victims to contact them. They also suggest that ransomware victims always contact law enforcement to report the incident, as there may be a decryptor that isn’t public yet. Continue reading “This Week In Security: The Battle Against Ransomware, Unicode, Discourse, And Shrootless”

The Metabolizer Is Turning Trash Into Treasure Even Faster Now

Do you remember [Sam Smith]’s Metabolizer from a few years back? In case you’ve forgotten, this baby takes trash and turns it into printed plastic objects, and it’s solar-powered to boot. Although the Metabolizer didn’t win the 2018 Hackaday Prize, [Sam] and his machine won many achievements that year, including the Open Hardware Challenge. It’s fantastic to see the project still improving.

To recap, the sun hits the solar panels and charge up the battery bank. Once there’s enough power to start the reaction, it gets dumped into a heating element that turns biomass into biochar. This smoke is cooled, collected, refined, and fed into a small gas generator, which produces DC power to run a 3/4-horsepower shredder and the trash printer.

[Sam] likens this beast to a Rube Goldberg machine in that it performs an overly-complicated chain reaction to do a simple task. We certainly see his point, but we think that this machine is worth so much more than those classic machines, which tend to do nothing useful at all and tend to consume many resources in the process.  On the contrary, the Metabolizer’s chain reaction starts with sunshine and ends with useful objects that keep plastic out of landfills. Honestly, it’s more akin to a compost heap with a PhD in Biology and a handful of steroids and a 3D printer attached.

Unfortunately, [Sam] couldn’t get a prototype working in time for the Prize, and he turned to Patreon to gain support after the $1,000 ran out. Three years and a ton of improvements later, [Sam] has a working prototype that’s cheaper, more efficient, and easier to build. But can it be built relatively easily by someone other than [Sam]? Consider the gauntlet thrown down.

Not happy with your standard-style compost pile? You need a DIY trommel to sift out the bad stuff.

Battle Robot Uses Carbon Fiber To Save Weight

ZAP! The saw is capable of delivering high-voltage discharges to damage its foes.

Combat robots come in all shapes and sizes, with regulating authorities often using weight limits to create a level playing field for competitors. [Hans Jørgen Grimstad] is building a robot to compete in a 4 kg class, and made some interesting design decisions to that end.

4 kg is not a lot of weight to play with. When considering the motors needed to propel the robot and the batteries needed to run everything, there’s then precious little weight left for weapons systems and armor plating.

Thus, in an effort to make the most of the weight limitations, [Hans] decided to use carbon fiber for the robot’s outer shell. The method used is a simple wet layup in a mold. We’d be supremely interested to see how this armor holds up in competition, versus more typical choices like aluminium and steel.

Other interesting features include a belt-driven saw, which [Hans] tests with his hands mere inches away and the robot’s motors powered up. Don’t do this if you value your fingers. This is paired with a high-voltage discharge taser module. When the saw gets close to another robot, it may cause sparks to jump to the enemy, damaging its electronics in the process. It’s something we haven’t seen too often, as such measures are actually banned in some contests.

Diehard enthusiasts in the battle robot community will likely have fierce opinions on many points of the design; have it out in the comments. It’s certainly not the first carbon-fiber bot, but it’s nice to see the fancy material being thrown in the ring.

We’ve seen other designers innovate, too, such as this remarkably successful walking robot build. Video after the break.

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