A Pi Pico Makes A Spectrum Laptop

December 23, 2024 by 8 Comments

There are many retrocomputer emulation projects out there, and given the relative fragility of the original machines as they enter their fifth decade, emulation seems to be the most common way to play 8-bit games. It’s easy enough to load one on your modern computer, but there are plenty of hardware options, too. “The computer we’d have done anything for back in 1983” seems to be a phrase many of them bring to mind, but it’s so appropriate because they keep getting better. Take [Stormbytes1970]’s Pi Pico-powered Sinclair ZX Spectrum mini laptop (Spanish language, Google Translate link), for example. It’s a slightly chunky netbook that’s a ZX Spectrum, and it has a far better keyboard than the original.

On the PCB is the Pico, the power supply circuitry, an SD card, and a speaker. But it’s when the board is flipped over that the interesting stuff starts. In place of the squidgy rubber keyboard of yore, it has a proper keyboard,. We’re not entirely sure which switch it uses, but it appears to be a decent one, nevertheless. The enclosure is a slick 3D-printed sub-netbook for retro gaming on the go. Sadly, it won’t edit Hackaday, so we won’t be slipping one in the pack next time we go on the road, but we like it a lot.

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Atoms For Peace: The US Nuclear Fleet Build-Out And Modern-Day Revival

December 23, 2024 by 24 Comments

By the end of World War II the world had changed forever, as nuclear weapons were used for the first and – to this date – only time in anger. Although the use of these weapons was barely avoided during the Korean War in the early 1950s, the dawning of the Atomic Age had come in the form of obliterated cities and an increasing number of these weapons being test fired around the world. It was against this background that on December 8, 1953, US President Dwight D. Eisenhower held his ‘Atoms for Peace’ speech, during which he would not only promote the peaceful use of nuclear technologies but also lay the groundwork for what would become the International Atomic Energy Agency (IAEA), as announced in the full speech.

Under the Eisenhower administration the US became one of the world’s nuclear power pioneers, as it competed with the UK and later others in establishing world’s firsts in commercial nuclear power. Dresden Generating Station would become the first purely commercial boiling water reactor (BWR) in 1960 and Yankee-Rowe, the first pressurized water reactor (PWR) in 1961. Following these, the number of new reactors planned and constructed kept increasing year over year, setting the trend for the few decades of the US nuclear power industry.

Today the US operates 94 reactors, which generate nearly 20% of the country’s electricity. Exactly how did the US build so many reactors before 1990, and how does this compare to the recent revival with both new builds and retired plants being put back into service?

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Silicone Tubing As Springs For Capacitive Touch Buttons

December 23, 2024 by 7 Comments

Capacitive touch buttons are a great way to turn just about any (non-conductive) surface into a button, but people generally dislike the lack of tactile feedback.  [KontinuumLab] apparently agreed and decided to experiment a bit with ways to make such buttons more springy. You can check out the results of those experiments in the video below. There are a few ways to add some spring to buttons and switches like these, including compliant mechanisms in the (3D-printed) plastic structure, but this isn’t always an option in a project. A separate plastic spring can be added, but they aren’t very durable. A metal spring works great but can be a bit of a hassle to integrate and they aren’t as cheap as the other options. So what about everyone’s favorite keyboard switch, the rubber dome type?

Silicone tubing is plentiful and (generally) cheap. It can be selected for just the right springiness and dimensions, and in the automated test that [KontinuumLab] ran, it is also very durable in this application. When your goal is to have a switch that activates at the end of the travel, this may work a treat, with the size of the silicone tube determining the travel before the finger gets close enough to trigger the switch. As rubber dome keyboards demonstrate, this is a highly reliable technology, though this version ditches the typical membrane for the capacitive touch sensor.

Sometimes, a metal spring is the right option, of course, such as when you want to make a surface a touch sensor and the PCB is at the other side of the enclosure. The fun part is that we have all of these options to make our projects work, with many being very affordable to hobbyists. Not all touch sensors require a finger, either.

Thanks to [BrightBlueJim] for the tip.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Keyboard-Mouse

December 23, 2024 by 10 Comments

One of the most annoying things about keyboard and mouse input has got to be the need to constantly switch between the two. Ever wish there was a single solution that combined them with elegance? Then you should definitely check out [lemosbor]’s Lapa keyboard, where the right half includes a mouse sensor.

A 36-key split board where the right half also operates as a mouse.
Image by [lemosbor] via reddit
Lapa, which is Russian for ‘paw’, certainly has that type of look. This hand-wired keyboard uses a pair of Pro Micros and an ADNS9800 optical sensor for mousing around. Under those ‘caps are MX blues, the OG clackers.

Let me just say that I love the look of this keyboard, and I don’t normally like black and brown together. But that oak — that oak is classy, and it looks good with the resin-and-varnish case. If you can handle a 36-key board — I myself cannot — then this would probably be a game changer. There are even slots for your palms to breathe.

Unfortunately it’s not open source, but a girl can dream, right? In the reddit post, [lemosbor] says that they would be interested in selling the next version, provided it’s the final one.

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Handheld Satellite Dish Is 3D Printed

December 23, 2024 by 8 Comments

Ham radio enthusiasts, people looking to borrow their neighbors’ WiFi, and those interested in decoding signals from things like weather satellites will often grab an old satellite TV antenna and repurpose it. Customers have been leaving these services for years, so they’re pretty widely available. But for handheld operation, these metal dishes can get quite cumbersome. A 3D-printed satellite dish like this one is lightweight and small enough to be held, enabling some interesting satellite tracking activities with just a few other parts needed.

Although we see his projects often, [saveitforparts] did not design this antenna, instead downloading the design from [t0nito] on Thingiverse. [saveitforparts] does know his way around a satellite antenna, though, so he is exactly the kind of person who would put something like this through its paces and use it for his own needs. There were a few hiccups with the print, but with all the 3D printed parts completed, the metal mesh added to the dish, and a correctly polarized helical antenna formed into the print to receive the signals, it was ready to point at the sky.

The results for the day of testing were incredibly promising. Compared to a second satellite antenna with an automatic tracker, the handheld 3D-printed version captured nearly all of the information sent from the satellite in orbit. [saveitforparts] plans to build a tracker for this small dish to improve it even further. He’s been able to find some satellite trackers from junked hardware in some unusual places as well. Antennas seem to be a ripe area for 3D printing.

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E-Paper Anniversary Counter Is A Charming Gift With Minimal Power Draw

December 23, 2024 by 12 Comments

[Lonyelon] wanted to build an anniversary gift for his girlfriend. He decided to say it with e-Paper, a wise choice given its persistence and longevity.

The project is an anniversary calendar. It displays a counter of the total time the couple has been together, measured in years, months, days, and hours—so it’s remarkably precise. [Lonyelon] also programmed it to display additional counters to create plenty of additional fun anniversaries—the couple can celebrate milestones like their 1000th day together, for example. It also cycles through a range of cute messages and displays photos of the couple together.

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Faster Integer Division With Floating Point

December 22, 2024 by 24 Comments

Multiplication on a common microcontroller is easy. But division is much more difficult. Even with hardware assistance, a 32-bit division on a modern 64-bit x86 CPU can run between 9 and 15 cycles. Doing array processing with SIMD (single instruction multiple data)  instructions like AVX or NEON often don’t offer division at all (although the RISC-V vector extensions do). However, many processors support floating point division. Does it make sense to use floating point division to replace simpler division? According to [Wojciech Mula] in a recent post, the answer is yes.

The plan is simple: cast the 8-bit numbers into 32-bit integers and then to floating point numbers. These can be divided in bulk via the SIMD instructions and then converted in reverse to the 8-bit result. You can find several code examples on GitHub.

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