Pour Yourself A Glass Of 100,000 Volts

August 5, 2020 by Tom Nardi 15 Comments

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.

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The Game Boy As A Midi Synthesiser

August 5, 2020 by Jenny List 6 Comments

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.

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Retro Game Bow Tie

August 4, 2020 by Orlando Hoilett 4 Comments

[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.

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A Hybrid Helical Antenna For The Es’hail-2 Geosynchronous Repeater

August 4, 2020 by Dan Maloney 14 Comments

Amateur radio operators like to say that working a contact in space can be done with a simple handheld transceiver and a homemade antenna. And while that’s true, it’s true only for low Earth orbit satellites such as the ISS. If you want to reach a satellite in geosynchronous orbit it’ll take a little more effort, and this dual-feed helical “ice cream cone” antenna could really help.

Until recently, the dream of an amateur radio repeater in geosynchronous orbit remained out of reach, but that changed with the launch of the Qatari satellite Es’hail-2 last year. Since then, hams from Brazil to Thailand have been using the repeater, and UK-based [Tech Minds] has been in the thick of the action. The antenna he presents is a hybrid design, needed because of the 2.4-GHz band uplink and 10-GHz downlink on the satellite, also known as QO-100. Both require a largish dish antenna, with the downlink requiring a low-noise block downconverter (LNB) and feed horn. The uplink side of [Tech Minds]’ antenna is a helical design, with three-and-a-half turns of heavy copper wire and a tuning section of copper strapping that attaches directly to an N-type connector. The helix is just the right size for the feed horn of an LNB for the downlink side, nestled in a hole in the helical antenna’s aluminum reflector disc. There are 3D-printed parts to support everything, plus a cone-shaped radome to keep it all safe from the elements.

It looks like a great design, but sadly, North American and East Asian hams can only dream about building one, since QO-100 is below the horizon for us. We’re jealous, but we’re still glad the repeater is up there. Check out this article for more on how Es’hail-2 got the first geosynchronous ham repeater.

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Bringing An IPod To The Modern NAND Era

August 4, 2020 by Bryan Cockfield 21 Comments

Flash storage was a pretty big deal back in the mid ’00s, although the storage sizes that were available at the time seem laughable by today’s standards. For example, having an iPod that didn’t have a spinning, unreliable hard drive was huge even if the size was measured in single-digit gigabytes, since iPods tended to not be treated with the same amount of care as something like a laptop. Sadly, these small iPods aren’t available anymore, and if you want one with more than 8GB of storage you’ll have to upgrade an old one yourself.

This build comes to us from [Hugo] who made the painstaking effort of removing the old NAND flash storage chip from an iPod Nano by hand, soldering 0.15mm enameled magnet wire to an 0.5mm pitch footprint to attach a breakout board. Once the delicate work was done, he set about trying to figure out the software. In theory the iPod should have a maximum addressable space of 64 GB but trying to get custom firmware on this specific iPod is more of a challenge and the drives don’t simply plug-and-play. He is currently using the rig for testing a new 8GB and new 16GB chip though but it shows promise and hopefully he’ll be able to expand to that maximum drive size soon.

The build is really worth a look if you’re into breathing new life into old media players. Sometimes, though all these old iPods really need to get working again is just to be thrown into a refrigerator, as some genius engineer showed us many years ago.

Official Arduboy Upgrade Module Nears Competition

August 4, 2020 by Tom Nardi 14 Comments

We’ve been big fans of the Arduboy since [Kevin Bates] showed off the first prototype back in 2014. It’s a fantastic platform for making and playing simple games, but there’s certainly room for improvement. One of the most obvious usability issues has always been that the hardware can only hold one game at a time. But thanks to the development of an official add-on, the Arduboy will soon have enough onboard storage to hold hundreds of games

Even the rear silkscreen was a community effort.

The upgrade takes the form of a small flexible PCB that gets soldered to existing test points on the Arduboy. Equipped with a W25Q128 flash chip, the retrofit board provides an additional 16 MB of flash storage to the handheld’s ATmega32u4 microcontroller; enough to hold essentially every game and program ever written for the platform at once.

Of course, wiring an SPI flash chip to the handheld’s MCU is only half the battle. The system also needs to have its bootloader replaced with one that’s aware of this expanded storage. To that end, the upgrade board also contains an ATtiny85 that’s there to handle this process without the need for an external programmer. While this is a luxury the average Hackaday reader could probably do without, it’s a smart move for an upgrade intended for a wider audience.

The upgrade board is currently available for pre-order, but those who know their way around a soldering iron and a USBasp can upgrade their own hardware right now by following along with the technical discussion between [Kevin] and the community in the “Project Falcon” forum. In fact, the particularly astute reader may notice that this official upgrade has its roots in the community-developed Arduboy cartridge we covered last year.

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MenoPlay Through The Pain Of Menopause

August 4, 2020 by Kristina Panos 7 Comments

Menopause, that fireworks finale of fertility, is like a second puberty that works in reverse. At least, that’s what we hear. Along with mood swings and acne, there are new joys like hot flashes that make you want to jump naked into the nearest snowdrift, or at least put your head in the freezer for a while. Sounds great; can’t wait.

The biggest problem with menopause is that it gives suffers pause when it comes to getting help. This is natural, they think. There’s nothing I can do but ride it out. Those who do seek relief are likely to find expensive products that only treat single symptoms. This dearth of solutions inspired [Moinak Ghosh] to create one system to rule them all, a wearable with a suite of sensors that’s designed to take the pause out of menopause.

MenoPlay will take temperature readings at the neck and pelvis and switch on a Peltier module worn on the back of the neck when it senses a hot flash in progress. Exercise is a natural defense against hormonal imbalance, but step counters are too easy to cheat or ignore. The MenoPlay system will model the user’s movements using 9DoF accelerometers and suggest exercises that fill in the gaps.

We particularly like the automation aspect of this wearable. After decades of manually tracking menstrual cycles and everything that implies, the idea of so much useful biological data being collected automatically and fed over BLE to a NodeRed application sounds wonderful.

Hot flashes may not feel useful internally, but would do a fine job of powering the right kind of flashlight.