Blast fishing — the act of using explosives underwater to kill entire schools of fish with shock waves — has been a widespread problem in the Philippines for decades. Although a few fishermen get rich from the first blast at a fresh site, it isn’t good for anyone in the long term, especially the coral and other sea life. Many blast fisherman use homemade explosives, often at the risk of losing fingers and limbs.

The local authorities have tried many tactics to deter the activity. Where education about the diminishing returns of blast fishing has failed, appeals to religion with strategically placed statuary of the Virgin Mary have been somewhat successful. [Ifthekar ahammad] has another idea, and it involves detecting the explosion, triangulating the position of the blast, and reporting it to the authorities as soon as possible.

The CBobby system works by analyzing the audio spectrum. It looks for transient changes from the ambient background noise levels, and analyzes duration and the frequencies it heard to decide whether there was an explosion or not. Plans to field test this in the Philippines have been dashed by the pandemic, but [ifthekar] has been hard at work testing in Germany with underwater speakers blasting out explosion noises. Already, the system can differentiate the blasts from various environmental sounds like ships, the bellows of large sea creatures, earthquakes, rain, and thunder.

Although the test rig is encased in neon orange acrylic, the actual blast fishing tattler will be disguised as a venomous stonefish, making it as appealing to mess with as fire ants or wasps.

Destructive blast fishing is all-around terrible, even though it’s done for survival. But what do we think of using drones to fish for sport?

source https://hackaday.com/2020/08/05/illegal-blast-fishing-detector-is-all-ears/

In space, so the Alien tagline goes, nobody can hear you scream. One of the most memorable pieces of movie promotion ever, it refers to the effect of the vacuum of space on the things human senses require an atmosphere to experience. It’s a lesson that Joss Whedon used to great effect with the Serenity‘s silent engine light-ups in Firefly, while Star Wars ignored it completely to give us improbable weapon noises in space battles.

Sound may not pass through the vacuum of space, but that’s not to say there are not things other than light for the senses. The Apollo astronauts reported that moon dust released a smell they described as akin to burnt gunpowder once it was exposed to the atmosphere inside their lander, and by now you may have heard that there is a Kickstarter that aims to recreate the smell as a fragrance. Will it replace the cloying wall of Axe or Lynx Africa body spray that pervades high-school boys’ changing rooms, or is it a mere novelty?

Smells Like Moon Dust

The gunpowder smell experienced by the Apollo crews is likely to have been caused by oxygen-sensitive compounds in the moon dust being oxidised by their first exposure to an atmosphere after having accumulated through billions of years of our satellite’s buffeting by solar winds. By the time the samples reached Earth-based scientists this process was long over, so no smell remains for analysis. Even the vacuum containers in which the astronauts were to catch a sample for return to earth without being compromised by a vacuum failed to stop it, it’s thought that their seals were compromised by the unexpectedly pervasive nature of the dust. Thus the “Eau de Luna” perfume will be a creation based only on the astronauts’ recollections rather than an analysis of the smell they experienced.

Like a Locker Room in Orbit

Moon dust may so far be our species’ only encounter with another heavenly body, but that isn’t to say that space is not without other smells. The NASA astronaut Jerry Linenger described “a distinct, burnt-dry smell“in the airlocks of the Soviet/Russian Mir space station after returning from space, which is probably analogous to the Moon smell. But numerous accounts from the residents of Mir and other stations talk of smells from a completely different source; the astronauts themselves.

In a space station it is impossible to open a window for a bit of extra ventilation, so as the early stations gave way to continuously-crewed modular outposts that stayed aloft for many years their atmospheres reflected the accumulated biome of all that had been brought to them by their crews. Mir was said to be infested with mould and fungus towards the end of its life, and in 2019 there was concern that the same fate was befalling the ISS. It’s said that the fluid displacement effect of weightlessness adversely affects the human sense of smell, which is perhaps fortunate for those who have to live with it.

So the space fragrance probably remains the closest that most of us will ever come to leaving the atmosphere, thus it could smell of anything at all and none of us would ever smell the real thing and be able to ask for a refund if it didn’t match. Does it matter though, for the hacker who doesn’t quite have everything? No doubt we’ll catch that open-airlock scent at one or other of next year’s events.

source https://hackaday.com/2020/08/05/the-smell-of-space/

You’d be hard pressed to find a hacker or maker who doesn’t have a soft spot for the tantalizing buzz and snap of a high voltage spark gap, but it remains the sort of project that most of us don’t take on personally. There’s a perceived complexity in building a device capable of shooting a proper spark through several inches of open air, with connotations of exotic components and massive hand-wound coils. Plus, nobody wants to inadvertently singe off their eyebrows.

While the latest video from [Jay Bowles] might not assuage anyone’s fear of performing impromptu electrolysis, it does at least prove that you don’t need to have a laboratory full of gear to produce six figure voltages. In fact, you don’t even need much in the way of electronics: the key components of this DIY Marx generator are made with little more than water and some household items.

This is made possible by the fact that the conductivity of water can be changed depending on what’s been dissolved into it. Straight tap water is a poor enough conductor that tubes of it can be used in place of high voltage resistors, while the addition of some salt and a plastic insulating layer makes for a rudimentary capacitor. You’ll still need wires to connect everything together and some bits of metal to serve as spark gaps, but nothing you won’t find lurking in the parts bin.

Of course, water and a smattering of nails won’t spontaneously generate electricity. You need to give it a bit of a kick start, and for that [Jay] is using a 15,000 volt DC flyback power supply that looks like it may have been built with components salvaged from an old CRT television. While the flyback transformer alone could certainly generate some impressive sparks, this largely liquid Marx generator multiplies the input voltage to produce a serious light show.

We’re always glad to see a new video from the perennially jovial [Jay] come our way. While his projects might not always be practical in the strictest sense, they never fail to inspire a lively discussion about the fascinating applications of high voltage.

source https://hackaday.com/2020/08/05/pour-yourself-a-glass-of-100000-volts/

You’d be hard pressed to find a hacker or maker who doesn’t have a soft spot for the tantalizing buzz and snap of a high voltage spark gap, but it remains the sort of project that most of us don’t take on personally. There’s a perceived complexity in building a device capable of shooting a proper spark through several inches of open air, with connotations of exotic components and massive hand-wound coils. Plus, nobody wants to inadvertently singe off their eyebrows.

While the latest video from [Jay Bowles] might not assuage anyone’s fear of performing impromptu electrolysis, it does at least prove that you don’t need to have a laboratory full of gear to produce six figure voltages. In fact, you don’t even need much in the way of electronics: the key components of this DIY Marx generator are made with little more than water and some household items.

This is made possible by the fact that the conductivity of water can be changed depending on what’s been dissolved into it. Straight tap water is a poor enough conductor that tubes of it can be used in place of high voltage resistors, while the addition of some salt and a plastic insulating layer makes for a rudimentary capacitor. You’ll still need wires to connect everything together and some bits of metal to serve as spark gaps, but nothing you won’t find lurking in the parts bin.

Of course, water and a smattering of nails won’t spontaneously generate electricity. You need to give it a bit of a kick start, and for that [Jay] is using a 15,000 volt DC flyback power supply that looks like it may have been built with components salvaged from an old CRT television. While the flyback transformer alone could certainly generate some impressive sparks, this largely liquid Marx generator multiplies the input voltage to produce a serious light show.

We’re always glad to see a new video from the perennially jovial [Jay] come our way. While his projects might not always be practical in the strictest sense, they never fail to inspire a lively discussion about the fascinating applications of high voltage.

source https://hackaday.com/2020/08/05/pour-yourself-a-glass-of-100000-volts/

In the world of chiptune music there are many platforms to choose from, each with their own special flavour tot heir sound. The Game Boy has a particular following, but it differs from some of its contemporary platforms in having a custom sound chip built into the same silicon as its processor. You can’t crank open a Game Boy and lift out the sound chip for your own synth project, instead you must talk to it through the Game Boy’s Z80 processor. This is something [Adil Soubki] knows well, as he’s completed a project that turns the handheld console into a MIDI synthesiser.

A Game Boy was designed to play games and not as a developer’s toy, so it doesn’t exactly roll out the red carpet for the hacker. He’s got under the console’s skin by mapping a section of its memory address map to the pins on a Teensy microcontroller board, and running some Game Boy code that reads the vaues there and uses them to configure the sound hardware. The Teensy handles the translation between MIDI and these byte values, turning the whole into a MIDI synthesiser. It’s a succesful technique, as can be seen in the video below the break. Best of all, the code is available, so you can have a go for yourself.

We’ve featured Game Boy synths before here at Hackaday, but usually they have been of the more conventional variety.

source https://hackaday.com/2020/08/05/the-game-boy-as-a-midi-synthesiser/

[Greg] loves hacking his bow ties. Back in high school, he added some bright RGB LEDs to the bow tie he wore to prom and even won the male best-dressed award. Recently he decided to try another bow tie hack, this time giving his tie some retro arcade game feels.

He decided to use an ATtiny85 and to experiment doing some more lower-level programming to refresh his skills. He wrote all his libraries from scratch which really helped him learn a lot about the ATtiny in the process. This also helped him make sure his code was as efficient as possible since he had quite a bit of memory constraints using the ATtiny85 (only 512 bytes of RAM).

He designed the body of the bow tie with wood. He fit all the electronics inside the body while allowing the ATtiny to protrude out of the body giving his bow tie some wanted hacker aesthetic. Of course, he needed to access the toggle switch to play the game, so he made a slot for that as well.

Nice addition to the electronics bow tie collection on Hackaday. Really aesthetic design if you ask us. And you know how much we love retro games.

source https://hackaday.com/2020/08/04/retro-game-bow-tie/