CEEFAX Lives! (Courtesy Of A Raspberry Pi)

January 7, 2022 by Jenny List 28 Comments

As analogue TV slides from memory, there’s a facet of it that’s fondly remembered by a band of enthusiasts. Teletext was an electronic viewdata information service digitally encoded in the frame blanking period, and a TV set with a decoder chip would provide access to many pages of news and other services all displayed in the characteristic brightly colored block graphics. It went the way of the dinosaur with the demise of analog TV, but for [Nathan Dane] the flame is kept alive with his own private version of the BBC’s CEEFAX service.

He has a particular enthusiasm for analog TV, and as such has his own in-house channel served by a UHF modulator. He shares with us the story of how he arrived at a teletext service, before writing code to scrape the BBC news and weather websites and populate his modern-day CEEFAX. Behind it all is a Raspberry Pi, with a vbit-pi board injecting the teletext signal onto the video, and raspi-teletext creating the pages from source material derived from a set of custom scraper scripts.

We like this project a lot, because while it’s not the first Pi teletext system we’ve encountered, the use of a scraped live feed makes it one of the most creative.

Thanks [kwikius] for the tip!

The Cucumber House That LEGO Built

January 4, 2022 by Jenny List 19 Comments

How far are you prepared to go to build a novelty seasonal ornament? Maybe a gingerbread house, or perhaps a bit of 3D printed glitter to hang on your Christmas tree. For [The Brick Wall], none of this was enough. Instead what was needed was a complete LEGO automated factory that builds a log cabin, from the unlikely raw material of cucumbers.

What has been created is the LEGO equivalent of a timber mill, with the various machines served by an overhead gantry crane. The cucumbers are trimmed to square, before being transferred to a saw which cuts out the notches for the interlocking corners. Another saw line chops the sections around door and windows to length, and finally the roof planks are cut in a vertical saw. The video below is reported as taking 83 days to complete from planning to filming, and 18 cucumbers to build the house. We’re not sure the cucumber will become a regular building material, but we salute the effort involved here.

Though this may be one of the biggest we’ve seen, we’ve featured many LEGO machines making things before.

Continue reading “The Cucumber House That LEGO Built” →

Genius Or Cursed, This USB-C Connector Is Flexible

January 1, 2022 by Jenny List 18 Comments

USB connectors have lent themselves to creative interpretations of their mechanical specifications ever since the first experimenter made a PCB fit into a USB-A socket. The USB-C standard with its smaller connector has so far mostly escaped this trend, though this might be about to change thanks to the work of [Sam Ettinger]. His own description of his USB-C connector using a flexible PCB and a BGA-packaged ATTiny84A microcontroller is “cursed”, but we can’t decide whether or not it should also be called “genius”.

Key to this inspired piece of connector fabrication is the realization that the thickness of BGA and flex PCB together comes to the required 0.7 mm. The BGA provides the necessary stiffness, and though it’s a one-sided connector it fits the space perfectly. There are several demo boards as proofs-of-concept, and the whole lot can be found in a GitHub repository.

We can see this technique finding a use in all kinds of diminutive USB-C projects, however cursed or genius it may be. We like to see projects that push the edges of what can be done with the medium, with a nod to a previous cursed USB-C device.

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A Tidy Cyberdeck That You Could Take Anywhere.

December 31, 2021 by Jenny List 18 Comments

The cyberdeck trend has evolved to a relatively straightforward formula: take a desktop computer and strip it to its barest essentials of screen, PCB, and input device, before clothing it in a suitably post-apocalyptic or industrial exterior. Sometimes these can result in a stylish prop straight from a movie set, and happily for [Patrick De Angelis] his Raspberry Pi based cyberdeck (Italian, Google Translate link) fits this description, taking the well-worn path of putting a Raspberry Pi and screen into a ruggedised flight case. Its very unremarkability is the key to its success, using a carefully-selected wired keyboard and trackpad combo neatly dodges the usual slightly messy arrangements of microcontroller boards.

If this cyberdeck has a special feature it’s in the extra wireless interfaces and the stack of antennas on its right-hand side. The Pi touchscreen is a little small for the case and perhaps we’d have mounted it centrally, but otherwise this is a box we could imagine opening somewhere in the abandoned ruins of a once-proud Radio Shack store for a little post-apocalyptic Hackaday editing. After all, your favourite online tech news resource doesn’t stop because the power’s gone out!

The No-MCU Fan Controller

December 31, 2021 by Jenny List 33 Comments

The default for any control project here in 2019 was to reach for a microcontroller. Such are their low cost and ubiquity that they can be used to replicate what might once have needed some extra circuitry, with the minimum of parts. But here we are at the end of 2021, and of course microcontrollers are hard to come by in a semiconductor shortage. [Hesam Moshiri] has a project that takes us back to a simpler time, a temperature controlled fan the way they used to be made, without a microcontroller in sight.

Old hands will no doubt guess where this design is heading, there is an LM35 temperature sensor producing a voltage proportional to its temperature, and half of an LM358 which forms a comparator against a static voltage from a divider. The LM358’s output drives a MOSFET which in turn switches on or off the fan motor. This type of circuit used to be the daily fare of simple control electronics in the days when a microcontroller represented a significant expense, and it’s still a handy circuit to be reminded of.

Have you forgotten sensors such as the LM35 in a world of on-board sensors? Time to refresh your sensing memory.

When A Ball Robot Becomes Two Wheels

December 30, 2021 by Jenny List 8 Comments

It’s now about six years since Star Wars: The Force Awakens first showed us the little spherical robot BB-8, but it’s fair to say that along the way we’ve not lost our collective fascination for rolling-ball robots. There have been plenty of attempts to make a fully-rolling device, but perhaps [Derek Lieber] has a better take on it by turning a spherical robot into a two-wheeled roller by the addition of a pair of tyres. Inspired by a Samsung prototype that never made it to market, it works by the wheels working against the machine’s low centre of gravity, and using a tilt sensor to control speed.

The ball chassis is a 3D printed shell, into which after much experimentation with motors, the final version put a pair of gimbal motors with a set of magnetic position sensors. Inside is an Arduino Mega and a custom motor driver board sporting an LM6234, with an XBee radio for remote control. Meanwhile the power comes from a set of three LiPo cells, and there is some extra lead ballast in the bottom to keep the whole thing balanced.

We’ve seen more conventional takes on a spherical robot in the past, but we’re particularly keen on this one, and excited to see where the future takes it.

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The Three Cent Motor Controller

December 29, 2021 by Jenny List 20 Comments

If you follow the world of small microcontrollers you will certainly be familiar with the usual fare of Atmel, ARM Cortex, PIC, and others. But these aren’t the smallest or cheapest devices, below them is an entire category of grain-of-dust microcontrollers with minimal capabilities and at rock bottom prices. Maybe the most well known are the Padauk series of chips, whose PIC12-like architecture can be had for literal pennies. These are the famous 3 cent microcontrollers, but despite their fame they have a bit of a reputation in our community for being difficult to work with. [Ben Lim] dispels some of those ideas, by Padauk-enabling a motor and encoder from a printer to make a three cent motor controller.

The Padauk doesn’t have on-chip peripherals such as SPI, instead its IDE provides bit-banging code to do the job. This and some PID motor controller code makes for a straightforward task on the little chip, and with the help of a probably considerably more expensive MAX14870 it can drive the motor. For the curious, the code can be found in a Git Hub repository. There may be more accomplished motor controllers to be found, but we doubt you’ll find one with a cheaper microcontroller.

Want to know what the fuss is about with the Padauk? Our colleague [Maya Posch] has you covered.