At this point, you gotta figure that you’re at least being listened to almost everywhere you go, whether it be a home assistant or your very own phone. So why not roll with the punches and turn lemons into something like a still life of lemons that’s a bit wonky? What we mean is, why not take our conversations and use AI to turn them into art? That’s the idea behind this next-generation digital photo frame created by [TheMorehavoc].
Essentially, it uses a Raspberry Pi and a Respeaker four-mic array to listen to conversations in the room. It listens and records 15-20 seconds of audio, and sends that to the OpenWhisper API to generate a transcript.
This repeats until five minutes of audio is collected, then the entire transcript is sent through GPT-4 to extract an image prompt from a single topic in the conversation. Then, that prompt is shipped off to Stable Diffusion to get an image to be displayed on the screen. As you can imagine, the images generated run the gamut from really weird to really awesome.
The natural lulls in conversation presented a bit of a problem in that the transcription was still generating during silences, presumably because of ambient noise. The answer was in voice activity detection software that gives a probability that a voice is present.
Naturally, people were curious about the prompts for the images, so [TheMorehavoc] made a little gallery sign with a MagTag that uses Adafruit.io as the MQTT broker. Build video is up after the break, and you can check out the images here (warning, some are NSFW).
[Allen] was inspired by a TED talk from over a decade ago that involved targeting flying mosquitoes with high-powered scanning lasers. This technology never really came to fruition, and raised many questions about laser safety and effectiveness.
Testing the idea with only two mirrors installed.
This solution keeps the lasers, but goes a slightly different route — two 10-watt lasers bounced between multiple mirrors to create a laser death grid. It goes without saying that 10 watt lasers will blind you near instantly even at great range, and can burn skin and cause all manner of other horrors. Bouncing them around with mirrors and waving them about at mosquitoes is a really poor idea when even incidental exposure can do real harm.
Indeed, the laser is so powerful that it burns holes in the mirrors [Allen] used in early testing. It was around this time that [styropyro] was brought in to help ensure everyone involved got through the project with their eyesight intact.
[Allen]’s crew wears laser safety goggles when operating the horrifying handheld device, which mitigates some risk. The team also quickly notice beams escaping from various directions, due in part to the holes burned in their clothes. Electing to wrap the device in a heatproof blanket to avoid accidentally dazzling any nearby pilots was an obvious idea but turning the device off and destroying it would have been smarter.
Sadly, despite looking like the coolest cyberpunk weapon we’ve seen in years, the device doesn’t even kill mosquitoes very effectively. The bugs largely avoided the device, and only a few that flew directly into a beam ended up being cooked. The whole time watching the video, we feared someone dropping the rig, leading to a 10-watt beam bouncing off and striking some poor innocent bystander.
Does your electronics desk have a lap drawer? And is it filled with random, disorganized detritus? Well, [Handy Bear] is here to show you that you can put so much more in every drawer you’ve got if you do it right. And boy, it sure looks like [Handy Bear] did it right.
Hidden inside this beautiful antique desk is plastic storage compartment after plastic storage compartment, all situated inside custom dividers made painstakingly from 3mm MDF. The first iteration, a cubbyhole arrangement, was not modular and looked crappy by [Handy Bear]’s standards.
Back to the drawing board and the scroll saw. [Handy Bear] came up with a new scheme that mimics the dividers in the plastic storage boxes they’re using for components and more. In addition to the slotted parts are open-top boxes for things like the multimeter, helping hands, and the ever-important label maker.
[Handy Bear] used hot glue and simple joinery for everything, sealing all the seams with a mixture of glue and water to keep it from turning to dust. We especially like the caliper holder for the lap drawer. You’ll notice that not quite everything fits inside the desk, so [Handy Bear] put the bigger stuff on a couple of IKEA carts. Be sure to check out the short build video and take the desk tour after the break.
At first, string processing might seem very hard to optimize. If you’re looking for a newline in some text, you have to check every character in the string against every type of newline, right? Apparently not, as [Abhinav Upadhyay] tells us how CPython does some tricks in string processing.
The trick in question is based on bloom filters, used here to quickly tell whether a character possibly matches any in a predefined set. A bloom filter works by condensing a set of more complex data to a couple of bits in an array. When an element is added, a bit is set, the index of which is determined by a hash function. To test whether an element might be in the filter, the same is done but by testing the bit instead of setting it. This effectively allows a fast check of whether an element might be in the filter.
CPython doesn’t stop optimizing there: instead of a complicated hash function, it simply uses the lowest 6 bits. It also has a relatively small bit array at only 64 bits which allows it to avoid memory all together, which in turn makes the comparisons much faster. [Abhinav] goes far into more detail in his article, definitely worth a read for any computer scientists among us.
[Helge Fykse (LA6NCA)] has a type, as they say. At least as far as radios are concerned, he seems to prefer elegant designs that keep the BOM to the minimum needed to get the job done. And Altoids tins — he really seems to like putting radios in Altoids tins.
This QRP transceiver for the 60-meter amateur radio band is a perfect example of that ethos. For the unfamiliar, QRP is Morse code shorthand for decreased power, and is generally used when hams are purposely building and operating radios that radiate very little power, typically below a watt. For this transceiver, [Helge] chose to use modern components, a marked but interesting departure from his recent tube-powered spy radios. The design is centered on a custom oscillator board he designed using an Arduino Pro Mini and an Si5351 oscillator chip. Other components include an ADE-1ASK frequency mixer, an antenna tuner module that can be swapped out for operating on different bands, a receiver that’s little more than a couple of op-amps, and a Darlington pair for an RF power amplifier. Everything fits neatly on a piece of copper-clad board inside the tin box.
As is his tradition, [Helge] was on the air in the field with this radio almost before the solder had time to cool. His first contact was a 240-km shot to a friend, who reported a fine signal from this little gem. And that’s with just powering it off a 9-volt battery when it’s designed to the typical 12-volt supplies hams favor; he estimates this resulted in a signal of about 200 mW. Not too shabby.
Honestly, we’d love to learn more about that oscillator board [Helge] used, and maybe get a schematic for it. We found a little bit about it on his web page, but not the juicy details. If you’re out there, [Helge], please share the wealth.
Distorted guitars were a big part of the rock revolution last century; we try to forget about the roll. As a youth, [David Hilowitz] couldn’t afford a loud aggressive amp, a distortion pedal, or even a proper electric guitar. This experience ended up teaching him that you can use random old audio hardware as a distortion effect.
[David’s] guitar journey started when he found a classical guitar on a dumpster. He learned to play, but longed for the sound of a proper electric guitar. Family friends gifted him a solitary pickup, intending he build a guitar, but he simply duct-taped it to his steel-strung classical instead. The only thing he lacked was an amp. He made do with an old stereo system and a record pre-amp. With his his faux-electric guitar plugged into the microphone input, he was blessed with a rudimentary but pleasant distortion that filled his heart with joy.
[David] goes on to explain the concepts behind distorted guitar sounds, and how his home hi-fi was able to serve as a passable starter amp when he was young and couldn’t afford better. He then goes on the hunt for more old gear at a local Goodwill store, finding a neat old tape deck that similarly produced some nice warm distorted tones. In [David’s] experience, old hi-fi gear with microphone inputs can generally do a decent job in this role, with electric guitar pickups typically overloading the preamps which expect a lower-level signal. It’s different to what you’d get from a Big Muff or Boss DS-1, but it’s a neat sound nonetheless.
Robots are cool. Robots you build yourself are cooler, especially ones that use stuff you have lying around already. Snoopy is a new open-source robot that uses an Arduino as a brain but with a 3D printed body and a short list of parts that can probably be sourced from the junk drawer. It’s still being developed, but it looks like a cool project heading in the right direction to produce an interesting robot.
It’s based on a new robot software platform called Kaia.ai that is built on top of the Robot Operating System 2 (ROS2), but with a more friendly and beginner-focused interface. Currently, the Snoopy project includes enough to get up and running with a printed frame and the electronics to install an Arduino running ROS2 that controls it. That’s an excellent place to start if you want to get into robotics, but without diving straight into the technical challenges of working with real-time operating systems.
It is also interesting that the previous project from the creator (called Kiddo) fell into the complexity trap, where you keep adding features and create an overly complex design that is a pain to build. Hopefully the designers have learned from Kiddo and will keep Snoopy simple.
We’ve covered plenty of other robot projects here at Hackaday, from ones that venture into nuclear reactors to ones that write your thank-you notes for you or give you hugs. We’ve even looked at how to give your robots a personality. Combine all those together with Snoopy and you could build a hugging, compassionate robot that has nice handwriting and can repair a nuclear reactor. And if you do, write it up and send it to our tips line!