Homebrewed Voice Assistant Keeps An Eye On Air Quality

November 5, 2021 by 3 Comments

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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Prepare For Wildfire Season With An Air Quality Monitor

November 4, 2021 by 12 Comments

For some reason, wildfire seasons in Australia, North America, and other places around the world seem to happen more and more frequently and with greater and greater fervor. Living in these areas requires special precautions, even for those who live far away from the fires. If you’re not sure if the wildfires are impacting your area or not, one of the tools you can build on your own is an air quality meter like [Costas Vav] shows us in this latest build.

The air quality indicator is based around an Adafruit Feather RP2040 which is in turn based on the 32-bit Cortex M0+ dual core processor. This makes for a quite capable processor in a small package, and helps accomplish one of the design goals of a rapid startup time. Another design goal was to use off-the-shelf components so that anyone could easily build one for themselves, so while the Feather is easily obtained the PMS5003 PM2.5 air quality sensor needed to be as well. From there, all of the components are wrapped up in an easily-printed enclosure and given a small (and also readily-available) OLED screen.

[Costas Vav] has made all of the files needed to build one of these available, from the bill of materials to the software running on the Pi-compatible board to the case designs. It’s a valuable piece of technology to have around even if you don’t live in fire-prone areas. Not only can wildfire smoke travel across entire continents but simple household activities such as cooking (especially with natural gas or propane) can decimate indoor air quality. You can see that for yourself with an army of ESP32-based air quality sensors.

Curious Marc Takes On Sewing Machine Repair

November 4, 2021 by 29 Comments

Even the most talented engineers can be stymied by simple repair projects. In this case, repairing a broken sewing machine has [CuriousMarc] all tangled up.  [Marc] is probably best known as a part of the team who managed to restore and boot up an apollo guidance computer, but he’s worked with plenty of other vintage machines.

This problem hit much closer to home. [Marc’s] daughter wanted to sew a Halloween costume. The machine would boot up fine, but when attempting to sew, it would make a bit of noise, then beep and display “The safety device has been activated”. Not very helpful.

The sewing machine in question is called “Baby Lock Decorator’s Choice” and is manufactured by Brother for Juken. [Marc] of course dug in, and quickly found himself stymied by a clamshell case that just didn’t want to come apart. This is the point where many of us would apply just a little too much force when prying and be rewarded with a broken case.

[CuriuosMarc] is thankfully the more patient sort. Rather than become [FuriousMarc], he carefully persevered to find a hidden screw holding things together. The screw could only be accessed by inserting a screwdriver through a tiny access hole on the front chassis of the machine.
With the screw out, a couple of molded clips were all that held the case sides together. After popping them, [Marc] was finally able to fix the real problem: A toothed belt that had slipped off its cog. That’s it — just a loose belt. The cryptic error code most likely was due to the machine realizing it the motor was on, but the machine wasn’t moving – which would generally indicate something stuck or tangled in the thread path.

This type of repair would be much easier if service manuals were readily available. We did a quick search for this model but didn’t find anything freely available.

Have you gotten stuck by a simple repair? Tell us about it down in the comments.

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Photo of an arid desert landscape

How Practical Is Harvesting Water From The Air?

October 29, 2021 by 117 Comments

Water is one of the most precious substances required to sustain human life. Unfortunately, in some areas like California, it’s starting to run out.

The ongoing drought has some people looking towards alternative solutions, such as sucking water out of the very air itself. In particular, a company called Tsunami Products has been making waves in the press with its atmospheric water generators, touting them as a solution for troubled drought-stricken areas, as reported by AP News. Today, we’ll look at how these machine capture water, and whether or not they can help in areas short on water.

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Hackaday Podcast 142: 65 Days Of Airtime, Racecars Staring At The Ceiling, A Pushy White Cane, And Soapy Water Rockets

October 29, 2021 by No comments

Hackaday editors Elliot Williams and Mike Szczys flap their gums about all the great hacks of the week. Something as simple as a wheel can be totally revolutionary, as we saw with a white cane mod for the visually impaired which adds an omniwheel that knows where it’s going. We enjoyed the collection of great hacks from all over the community that went into a multi-two-liter water rocket build. You’ll hear Elliot and Mike’s great debate about the origin of comments in computer code. And we spend plenty of time joking around about the worlds longest airplane flight (it was in a tiny Cessna and lasted over two months!)

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB)

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Ethernet Cable Turned Into Antenna To Exploit Air-Gapped Computers

October 27, 2021 by 30 Comments

Good news, everyone! Security researcher [Mordechai Guri] has given us yet another reason to look askance at our computers and wonder who might be sniffing in our private doings.

This time, your suspicious gaze will settle on the lowly Ethernet cable, which he has used to exfiltrate data across an air gap. The exploit requires almost nothing in the way of fancy hardware — he used both an RTL-SDR dongle and a HackRF to receive the exfiltrated data, and didn’t exactly splurge on the receiving antenna, which was just a random chunk of wire. The attack, dubbed “LANtenna”, does require some software running on the target machine, which modulates the desired data and transmits it over the Ethernet cable using one of two methods: by toggling the speed of the network connection, or by sending raw UDP packets. Either way, an RF signal is radiated by the Ethernet cable, which was easily received and decoded over a distance of at least two meters. The bit rate is low — only a few bits per second — but that may be all a malicious actor needs to achieve their goal.

To be sure, this exploit is quite contrived, and fairly optimized for demonstration purposes. But it’s a pretty effective demonstration, but along with the previously demonstrated hard drive activity lights, power supply fans, and even networked security cameras, it adds another seemingly innocuous element to the list of potential vectors for side-channel attacks.

[via The Register]

Tech In Plain Sight: Air Conditioning

October 27, 2021 by 41 Comments

I’m always amazed that technology can totally wipe out industries. Sure, some people make a living making horseshoes, for example, but the demand for them is way down compared to what it would have been when horses were the normal mode of transportation. But even so, people still make horseshoes. But think about the ice harvesting business. Never heard of it? Turns out, before refrigeration, there was a huge business of moving ice from where it naturally occurred to other places and storing it, usually underground with a lot of insulation. As far as I know, that business — including the neighborhood ice man — is totally gone now except for some historical exhibitions. We take refrigeration and air conditioning for granted, but it hasn’t been that long ago that ice was a luxury and your own reprieve from the heat was a fan.

Early Cooling

The story starts a little earlier than you might expect. In the 1840s, physician John Gorrie was concerned about “the evils of high temperature.” His hospital in Florida imported ice using the aforementioned ice trade and it wasn’t cheap nor was it very effective.

Undeterred, he developed a machine that used a horse, a waterwheel, steam, or wind power to drive a compressor to create ice. He got a patent in 1851 but it failed to catch on before his financial backer died. In fact, Oliver Evans had the idea in 1805 but never built a working machine. Jacob Perkins patented the first compression cooler in 1834, again with little practical use.

When U.S. President Garfield was shot, Navy engineers built a cooling box using cloths soaked in ice water to cool the president’s hospital room by 20 degrees. Since the mortally wounded president survived 80 days after the shooting, we presume he appreciated the comfort.

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