Switching Regulators: Mistake Fixing For Dummies

September 19, 2024 by 30 Comments

Some time ago, while designing the PCB for the Sony Vaio replacement motherboard, I went on a quest to find a perfect 5 V boost regulator. Requirements are simple – output 5 V at about 2A , with input ranging from 3 V to 5 V, and when the input is 5 V, go into “100% duty” (“pass-through”/”bypass”) mode where the output is directly powered from the input, saving me from any conversion inefficiencies for USB port power when a charger is connected. Plus, a single EN pin, no digital configuration, small footprint, no BGA, no unsolicited services or offers – what more could one ask for.

As usual, I go to an online shop, set the parameters: single channel, all topologies that say “boost” in the name, output range, sort by price, download datasheets one by one and see what kind of nice chips I can find. Eventually, I found the holy grail chip for me, the MIC2876, originally from Micrel, now made by Microchip.

MIC2876 is a 5 V regulator with the exact features I describe above – to a T! It also comes with cool features, like a PG “Power good” output, bidirectional load disconnect (voltage applied to output won’t leak into input), EMI reduction and efficiency modes, and it’s decently cheap. I put it on the Sony Vaio board among five other regulators, ordered the board, assembled it, powered it up, and applied a positive logic level onto the regulator’s EN pin.

Immediately, I saw the regulator producing 3 V output accompanied by loud buzzing noise – as opposed to producing 5 V output without any audible noise. Here’s how the regulator ended up failing, how exactly I screwed up the design, and how I’m creating a mod board to fix it – so that the boards I meticulously assembled, don’t go to waste.

Some Background… Noise

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Latest PiEEG Shield Now Offers 16 Channels

September 17, 2024 by 24 Comments

We’ve previously covered the PiEEG, an affordable brain-computer interface (BCI) shield designed to connect to the Raspberry Pi. The open source project developed by [Ildar Rakhmatulin] is intended to allow students and hobbyists to experiment with detecting electroencephalography (EEG), electromyography (EMG), and electrocardiography (ECG) biosignals — unlocking a wide array of applications ranging from assistive tech to gaming.

Now, the PiEEG hardware has been upgraded to detect sixteen channels via either wet or dry electrodes. The new board, referred to as the PiEEG-16, offers up the same ease of use and features as its predecessor, including the ability to read out signals from the device using Python scripts. Compared to the eight channels supported by the previous generation of hardware, the PiEEG-16 promises to provide the fine-grain data required for more complex operations.

Since we last checked in with the PiEEG back in 2023, [Ildar] says the project has attracted plenty of attention. To help document how the community is using the capability offered by these BCIs, he’s added a page on the project’s site to show off what folks are building with the technology.

Inevitably, some express concern when talking about non-professionals working with brain interfacing hardware. But the project’s documentation is quick to point out that efforts have been taken to make the endeavour as risk-free as possible. The most important thing to remember is that the Raspberry Pi and PiEEG are intended to be powered by batteries so as to remain completely isolated. Similarly, there’s no need to connect the devices to a mains-powered computer, as everything happens on the Pi itself.

Even still, it’s made clear that the PiEEG-16 is not a medical device, and has received no formal certifications. If you want to experiment with this technology, you do so at your own risk. Just something to keep in mind…no pun intended.

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2024 Hackaday Superconference Speakers, Round One

September 17, 2024 by 6 Comments

Supercon is the Ultimate Hardware Conference and you need to be there! We’ve got a stellar slate of speakers this year — way too many to feature in one post. So here’s your first taste, and a reminder that Supercon will sell out so get your tickets now before it’s too late.

In addition to the full-length talks, we’ve got a series of Lightning Talks, so if you want to share seven minutes’ of insight with everyone there, please register your Lightning Talk idea now.

But Supercon has a lot more than just talks! The badge heavily features Supercon Add-Ons, and we want to see the awesome SAOs you are working on. There will be prizes, and we’ll manufacture four of our favorite designs in small batches for the winners, and make a full run for Hackaday Europe in 2025. Want to know more about SAOs? They’re the ideal starter PCB project.

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Ask Hackaday, What’s Next?

September 6, 2024 by 39 Comments

Writing for Hackaday involves drinking from the firehose of tech news, and seeing the latest and greatest of new projects and happenings in the world of hardware. But sometimes you sit back in a reflective mood, and ask yourself: didn’t this all used to be more exciting? If you too have done that, perhaps it’s worth considering how our world of hardware hacking is fueled, and what makes stuff new and interesting.

Hardware projects are like startup fads

An AliExpress page of Nixie clock kits
When AliExpress has hundreds of kits for them, Nixie clocks are a mature project sector, by any measure.

Hardware projects are like startup fads, they follow the hype cycle. Take Nixie clocks for instance, they’re cool as heck, but here in 2024 there’s not so much that’s exciting about them. If you made one in 2010 you were the talk of the town, in 2015 everyone wanted one, but perhaps by 2020 yours was simply Yet Another Nixie Clock. Now you can buy any number of Nixie clock kits on Ali, and their shine has definitely worn off. Do you ever have the feeling that the supply of genuinely new stuff is drying up, and it’s all getting a bit samey? Perhaps it’s time to explore this topic.

I have a theory that hardware hacking goes in epochs, each one driven by a new technology. If you think about it, the Arduino was an epoch-defining moment in a readily available and easy to use microcontroller board; they may be merely a part and hugely superseded here in 2024 but back in 2008 they were nothing short of a revolution if you’d previously has a BASIC Stamp. The projects which an Arduino enabled produced a huge burst of creativity from drones to 3D printers to toaster oven reflow and many, many, more, and it’s fair to say that Hackaday owes its early-day success in no small part to that little board from Italy. To think of more examples, the advent of affordable 3D printers around the same period as the Arduino, the Raspberry Pi, and the arrival of affordable PCB manufacture from China were all similar such enabling moments. A favourite of mine are the Espressif Wi-Fi enabled microcontrollers, which produced an explosion of cheap Internet-connected projects. Suddenly having Wi-Fi went from a big deal to built-in, and an immense breadth of new projects came from those parts. Continue reading “Ask Hackaday, What’s Next?” →

Launching Model Airplanes With A Custom Linear Induction Motor

September 5, 2024 by 18 Comments

Launching things with electromagnetism is pretty fun, with linear induction motors being a popular design that finds use from everywhere in hobby designs like [Tom Stanton]’s to the electromagnetic launchers on new US and Chinese aircraft carriers. Although the exact design details differ, they use magnetic attraction and repulsion to create a linear motion on the propulsive element, like the sled in [Tom]’s design. Much like the electromagnetic catapults on a Gerald R. Ford-class carrier, electrical power is applied to rapidly move the sled through the channel, akin to a steam piston with a steam catapult.

Model airplane sparking its way through the launcher’s channel. (Credit: Tom Stanton, YouTube)

For [Tom]’s design, permanent magnets are used along both sides of the channel in an alternating north/south pole fashion, with the sled using a single wound coil that uses brushes to contact metal rails along both sides of the channel. Alternating current is then applied to this system, causing the coil to become an electromagnet and propel itself along the channel.

An important consideration here is the number of turns of wire on the sled’s coil, as this controls the current being passed, which is around 90 A for 100 turns. Even so, the fastest sled design only reached a speed of 44 mph (~71 km/h), which is 4 mph faster than [Tom]’s previous design that used coils alongside the channels and a sled featuring a permanent magnet.

One way to increase the speed is to use more coils on the sled, with a two-coil model launching a light-weight model airplane to 10.2 m/s, which is not only a pretty cool way to launch an airplane, but also gives you a sense of appreciation for the engineering challenges involved in making an electromagnetic catapult system work for life-sized airplanes as they’re yeeted off an aircraft carrier and preferably not straight into the drink.

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Boss Byproducts: The Terrible Beauty Of Trinitite

September 4, 2024 by 17 Comments

While some byproducts recall an idyllic piece of Americana, others remind us that the past is not always so bright and cheerful. Trinitite, created unintentionally during the development of the first atomic bomb, is arguably one of these byproducts.

A see-through vial pendant with several small samples of Trinitite.
A Trinitite pendant. Image via Galactic Stone

Whereas Fordite kept growing back for decades, all Trinitite comes from a single event — the Trinity nuclear bomb test near Alamogordo, New Mexico on July 16, 1945. Also called ‘atomsite’ and ‘Alamogordo glass’, ‘Trinitite’ is the name that stuck.

There wasn’t much interest in the man-made mineral initially, but people began to take notice (and souvenirs) after the war ended. And yes, they made jewelry out of it.

Although there is still Trinitite at the site today, most of it was bulldozed over by the US Atomic Energy Commission in 1953, who weren’t too keen on the public sniffing around.

There was also a law passed that made it illegal to collect samples from the area, although it is still legal to trade Trinitite that was already on the market. As you might expect, Trinitite is rare, but it’s still out there today, and can even be bought from reputable sources such as United Nuclear. Continue reading “Boss Byproducts: The Terrible Beauty Of Trinitite” →

An adorable mini rack for NUCs, plus a 5-port switch.

A Mini NUC Rack For Your Desktop

September 1, 2024 by 16 Comments

We (well, some of us) are complete suckers for things that are both much smaller and much larger than life. And if that thing actually does what its supposed to? Squee! So naturally, we rushed to bring you news of this mini NUC rack designed by [Jeremy Weatherford].

Inspiration comes from a lot of places, often times from stuff that lives on your desk. [Jeremy] had a pile of NUCs and thought they resembled a mini rack already, so why not build them one to live in? It was the perfect excuse to learn CAD, so off [Jeremy] went. Although this is a mini rack, the parts were too big to print. Another opportunity presented itself, and [Jeremy] tried out an online service to get the acrylic cut.

Assembly may have been fiddly with super glue all over the nice black acrylic, but [Jeremy] learned an important tip: excess glue can be removed with vegetable oil. Once it was built, he decided to make it into a control system lab and even found a perfect little five-port switch to top it off. The logo plate, of course, is the icing on this cake.

If you prefer your tower of mini-computers to be extruded, we covered a clever design from [Jay Doscher] back in May.