Because You Can: Linux On An Arduino Uno

There are a few “Will it run” tropes when it comes to microcontrollers, one for example is “Will it run Doom?“, while another is “Will it run Linux?”. In one of the lowest spec examples of the last one, [gvl610] has got an up-to-date Linux kernel to boot on a vanilla Arduino Uno. And your eyes didn’t deceive you, that’s a full-fat kernel rather than the cut-down μClinux for microcontrollers.

Those of you who’ve been around a while will probably have guessed how this was done, as the ATmega328 in the Uno has no MMU and is in to way powerful enough for the job. It’s running an emulator, in this case just enough RISC-V to be capable, and as you’d imagine it’s extremely slow. You’ll be waiting many hours for a shell with this machine.

The code is written in pure AVR C, and full instructions for compilation are provided. Storage comes from an SD card, as the ATmega’s meagre 32k is nowhere near enough. If you’re having a bit of deja vu here we wouldn’t blame you, but this one is reputed to be worse than the famous 2012 “Worst PC Ever“, which emulated ARM instead of RISC-V.

Thanks [Electronics Boy] for the tip!

Restoration Of A Thinkpad 701C

This is like ASMR for Hackers: restoration specialist [Polymatt] has put together a video of his work restoring a 1995 IBM Thinkpad 701c, the famous butterfly keyboard laptop. It’s an incredible bit of restoration, with a complete teardown and rebuild, even including remaking the decals and rubber feet.

[Polymatt] runs Project Butterfly, an excellent site for those who love these iconic laptops, offering advice and spare parts for restoring them. In this video, he does a complete teardown, taking the restored laptop completely apart, cleaning it out, and replacing parts that are beyond salvaging, like the battery, and replacing them. Finally, he puts the whole thing back together again and watches it boot up. It’s a great video that we’ve put below the break and is well worth watching if you wonder about how much work this sort of thing involves: the entire process took him over two years.

We’ve covered some of his work in the past, including the surprisingly complicated business of analyzing and replacing the Ni-Cad battery that the original laptop used. Continue reading “Restoration Of A Thinkpad 701C”

Crabapplepad Folding Keyboard Is Actually Pretty Sweet

[Sergei Silnov] was quite attached to the Microsoft Natural Ergonomic 4000 keyboard, an updated version of their Natural keyboard that brought so many into the split fold. But once [Sergei] started writing notes in coffee shops, it was time for something portable.

The trouble with many portable keyboards, especially folding ones, is that they’re not often comfortable to type on. However, the Crabapplepad, a sleek, elegant offering, looks as though it begs to differ.

[Sergei] truly thought of everything and packed it into this 2cm thick wonder. There’s a little kickstand to hold your phone, or you can just throw an Apple trackpad between the halves and it magnetically attaches. Inside there’s a Seeed Studio XIAO nRF52840, and the switches are the extremely thin and hard-to-find Kailh PG1425 X, a sweet-looking scissor switch.

The only problem with X-switches is that there is only one type of keycap for them at the moment, and there aren’t any homing bums for F and J. To get around this, [Sergei] designed some 3D-printed frames to go around the keycaps and make them more distinct. Yes, this beauty it is open source, so go forth and be comfortable in absolute style. Don’t forget to check out the demo after the break.

To be honest, there once was a pretty good folding keyboard — the Palm Portable. Don’t worry; someone made a Bluetooth adapter for them.

Continue reading “Crabapplepad Folding Keyboard Is Actually Pretty Sweet”

This Packable Ham Radio Antenna Is Made From Nothing But Tape

On today’s episode of “Will It Antenna?”, [Ben Eadie (VE6SFX)] designs and tests an antenna made entirely of tape, and spoiler alert — it works pretty well.

By way of background, the basic design [Ben] uses here is known as a J-pole, a popular “my first antenna” design for amateur radio operators looking to go beyond the stock whip antenna that comes with that cheap handy-talkie you just can’t resist buying as soon as you get your license. Usually, though, hams will build their J-poles from rigid materials, copper water pipe being a typical choice. Copper has the advantage of being easily sourced, and also results in a self-supporting, weather-resistant antenna that’s easy to mount outdoors. However, copper is getting to be egregiously expensive, and a couple of meters of water pipe isn’t exactly amenable to portable operation, if that’s your jam.

To solve those problems, [Ben] decided to keep his copper use to a minimum with a roll of copper foil tape. He doesn’t provide any specs on the tape, but it looks like it’s about 6 mm (1/4″) wide and judging by a quick Amazon search, probably goes for about $10 a roll. He starts the build with a couple of strips of plain old duck tape — we’ve already had the “duck vs. duct” argument — laid out with the sticky sides together. The copper foil is applied to the duck tape backing using dimensions from any of the J-pole calculators available online. Dimensions are critical to getting good performance from a J-pole, and this is where [Ben]’s tape design shines. Element too long? No problem, just peel up a bit and tear some off. Did you go too far and make an element too short? Easy — just stick on an extension piece of foil. Tuning the location of the feedline connection was a snap, too, with movable terminals held in place with magnets.

Once everything was tuned up, [Ben] soldered down the feed points and covered the foil with a protective layer of duck tape. The antenna performed swimmingly, and aside from costing almost nothing to build, it weighs very little, rolls up to fit in a pack for field operations, and can easily be hoisted into a tree for better coverage. Looks like we’ll be putting in an order for some copper tape and building one of these too. Continue reading “This Packable Ham Radio Antenna Is Made From Nothing But Tape”

Teletext In Ireland, Another Broadcasting Leftover Bites The Dust

Over the years we’ve reported on the passing of a few of the broadcasting technologies of yesteryear, such as analogue TV in America, or AM radio in Europe. Now it’s the turn of an early digital contender, as one of the few remaining holdouts of old-style teletext is to shut down its service. The Irish broadcaster RTÉ is to turn off its teletext service Aertel, which has been live in some form continuously since 1986.

Like all European countries, Ireland has had only digital TV for quite a few years now. The linked RTÉ piece implies that the Aertel service has been carried as the old-style data in the frame blanking period even when part of a digital multiplex rather than the newer digital teletext system, so we’d be really grateful if some of our Irish readers could flick on their TVs and confirm that.

In an internet-connected world it seems quaint that a limited set of curated pages could once have been such a big deal, but it’s easy to forget that for many the teletext system provided their first ever taste of online information. As it shuffles away almost unnoticed we won’t miss counting through the page numbers cycling by in the top corner as we waited for our page to load, but it’s worth marking its final passing from one of the few places it could still be found.

Teletext does pop up in a few projects here, most recently as the display engine for a game of DOOM.

Hackaday Podcast Ep 240: An Amazing 3D Printer, A Look Inside Raspberry Pi 5, And Cameras, Both Film And Digital

Date notwithstanding, it’s your lucky day as Elliot and Dan get together to review the best hacks of the week. For some reason, film photography was much on our writers’ minds this week, as we talked about ways to digitalize an old SLR, and how potatoes can be used to develop film (is there a Monty Python joke in there?) We looked at a 3D printer design that really pulls our strings, the custom insides of the Raspberry Pi 5, and the ins and outs of both ferroresonant transformers and ham radio antennas. Learn about the SMD capacitor menagerie, build a hydrogen generator that probably won’t blow up, and listen to the differences between a mess of microphones. And that’s not all; the KIM-1 rides again, this time with disk drive support, Jenny tests out Serenity but with ulterior motives, and Kristina goes postal with a deep dive into ZIP codes.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Grab a copy for yourself if you want to listen offline.

Continue reading “Hackaday Podcast Ep 240: An Amazing 3D Printer, A Look Inside Raspberry Pi 5, And Cameras, Both Film And Digital”

National Research Council laboratories in Ottawa

Canada Abruptly Ends Official Time Signal

In a sudden move that was noted not only by Canadian media, but also international media channels, the National Research Council Time Signal that was broadcast by Canadian Broadcasting Corporation (CBC) on CBC Radio One since November 5 1939 was turned off on October 9th, after eighty-four years, one world war, countless generations, and the rise of modern technology. Although perhaps obsolete by today’s standards, this 15 to 60 second long broadcast at 13:00 Eastern Time every single day has been a constant in the life of Canadians, whether they tuned into local radio, or (increasingly) via Internet radio.

The NRC Time Signal consisted out of a series of 800 Hz sinewave ‘beeps’ followed by a second-long signal to indicate the top of the hour. Back in the day this was extremely useful to sync one’s clocks, watches and other time-keeping devices to. Yet between the transmission delays caused by Internet radio and the increased availability of NTP and other time sources on modern-day devices, the signal’s main use appears to have become a nostalgic reminder of what once was a constant of each and every day.

In this regard the public response to the rather unceremonious decommissioning without prior announcement was rather predictable. After all, even if it wasn’t that useful, why throw out something that is more recognizable than any other radio jingle for generations of Canadians?

Top image: National Research Council laboratories in Ottawa.