For Today Only, Pi=3

February 29, 2024 by 47 Comments

In 1897 the state assembly of the American state of Indiana famously tried and failed to pass a bill which would have had the effect of denying the value of the mathematical constant Pi. It was an attempt to define a method to “square the circle”, or draw a square of the same area as a given circle through a series of compass and straight edge steps. It’s become something of a running joke and internet meme, and of course defining Pi exactly remains as elusive as ever.

Today and today alone though, you can in one sense claim that Pi is 3, because it’s twelve years since the launch of the original Raspberry Pi. The 29th of February 2012 was a leap day, and today being the third leap day since, could be claimed by a date pedant to be the third birthday of the little board from Cambridge. It’s all a bit of fun, but the Pi folks have marked the occasion by featuring an LED birthday cake.

Three leap days ago, your scribe was up at the crack of dawn to be one of the first to snag a board, only to witness the websites of the two distributors at the time, RS and Farnell, immediately go down under the denial of service formed by many thousands of other would-be Pi owners with the same idea. It would be lunchtime before the sites recovered enough to slowly buy a Pi, and it would be May before the computer arrived.

The Pi definitely arrived with a bang, but at tweleve years old is it still smoking? We think so, while it’s normalized the idea of an affordable little board to run Linux to the extent that it’s one of a crowd, the Pi folks have managed to stay relevant and remain the trend setter for their sector rather than Arduino-style becoming an unwilling collective term.

We’ve said this before here at Hackaday, that while the Pi boards are good, it’s not them alone which sets them apart from the clones but their support and software. Perhaps their greatest achievement is that a version of the latest Raspberry Pi OS can still run on that board ordered in February 2012, something unheard of elsewhere in single board computers. If you still have an original Pi don’t forget this, while it’s not the quickest any more there are still plenty of tasks at which they can excel. Meanwhile with their move into branded silicon and their PCIe architecture move we think things are looking exciting, and we look forward to another 12 years and three birthdays for them. Happy 3rd birthday, Raspberry Pi!

Washing Machine Motors Unlocked

February 29, 2024 by 19 Comments

There’s great potential in salvaging a motor from a broken appliance, but so often the part in question is very specific to its application, presenting a puzzle of wires to the experimenter. This was very much the case with older washing machines and other white goods, and while their modern equivalents may have switched to more understandable motors, there are still plenty of the older ones to be had. [Matthias random stuff] sheds a bit of light on how these motors worked, by means of a 1980s Maytag washing machine motor.

Many of us will be used to old-style induction motors, in which two windings were fed out of phase via a large capacitor. This one doesn’t have a capacitor, instead it has a primary winding and a secondary one with a higher resistance. We’re not quite sure the explanation of the resistance contributing to a phase shift holds water, however this winding is connected in for a short time at start-up by a centrifugal switch. Even better, reversing its polarity reverses the direction of the motor.

The result is a mess of wires demystified, and a mains powered motor with a bit of strength for your projects. We’ve let a few of these motors slip through our fingers in the past, perhaps we shouldn’t have been so hasty.

This is a subject that we’ve looked at in the past.

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The White House Memory Safety Appeal Is A Security Red Herring

February 29, 2024 by 107 Comments

In the Holy Programming Language Wars, the lingua franca of system programming – also known as C – is often lambasted for being unsecure, error-prone, and plagued with more types of behavior that are undefined than ones that are defined by the C standards. Many programming languages were said to be ‘C killers’, yet C is still alive today. That didn’t stop the US White House’s Office of the National Cyber Director (ONCD) from putting out a report in which both C and C++ got lambasted for being ‘unsafe’ when it came to memory management.

The full report (PDF) is pretty light on technical details, while citing only blog posts by Microsoft and Google as its ‘expert sources’. The claim that memory safety issues are the primary cause of CVEs is not substantiated, or at least ignores the severity of CVEs when looking at the CISA statistics for active exploits. Beyond this call for ‘memory safety’, the report then goes on to effectively call for more testing and validation, while kicking in doors that were opened back in the 1970s already with the Steelman requirements and the High Order Language Working Group (HOLWG) of 1975.

What truly is the impact and factual basis of the ONCD report?

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A cat sits on a dark green mid-century modern bench next to a cat-sized black piano. A black bowl sits beneath the piano to catch food. An abstract green, blue, and tan picture in a black frame is on the wall above the cat and a black bar stool can be seen around the corner. It looks like the sort of photo you'd see on Instagram or in an interior design magazine.

Piano Feeder Gets Pets Playing For Their Supper

February 29, 2024 by 21 Comments

If you ever watched a video of Piano Cat and wondered if your cat could learn to play, then [Sebastian Sokołowski] has a possible solution with this combination piano tutor and cat feeder.

Starting with a CNC cut MDF enclosure, [Sokołowski] developed a cat feeder that would fit in the rear of the piano. It had to be reliable, consistent, and easy to disassemble. He walks us through his testing for each of these features and says the feeder was the most difficult part of the project to develop due to the propensity of pet feeder mechanisms to jam.

A custom PCB takes the key presses from the piano (with functional black keys) and outputs the sound from a speaker in the back. Lessons progress through increasing difficulty automatically, encouraging your cat to learn what the different keys can do. Food is dispensed after a performance or on a schedule set through the accompanying smartphone app. All the files are available if you want to build your own, but there is a wait list available if you want a completed version to give to less technically-inclined cat staff.

We’re certainly no stranger to the creatures that rule the internet here at Hackaday, having featured other cat feeders, new research into spaying cats, or even open source robo-cats.

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NASA Found Another Super Earth With Tantalizing Possibilities

February 29, 2024 by 57 Comments

Earth is a rather special place, quite unlike the other planets in the solar system. It’s nestled at the perfect distance from the sun to allow our water to remain liquid and for life to flourish in turn. It’s a rare thing; most planets are either too close and scorching hot, or too far and freezing cold.

NASA is always on the hunt for planets like our own, and recently found a new super-Earth by the name of TOI-715b. The planet is larger than our own, but it’s position and makeup mean that it’s a prime candidate for further study. Let’s take a look at how NASA discovered this planet, and why it’s special.

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An Automotive Locksmith On The Flipper Zero And Car Theft

February 29, 2024 by 61 Comments

Here in the hacker community there’s nothing we love more than a clueless politician making a fool of themselves sounding off about a technology they know nothing about. A few days ago we were rewarded in spades by the Canadian Minister of Innovation, Science and Industry François-Philippe Champagne, who railed against the Flipper Zero, promising to ban it as a tool that could be used to gain keyless entry to a vehicle.

Of course our community has roundly debunked this assertion, as capable though the Flipper is, the car industry’s keyless entry security measures are many steps ahead of it. We’ve covered the story from a different angle before, but it’s worth returning to it for an automotive locksmith’s view on the matter from [Surlydirtbag].

He immediately debunks the idea of the Flipper being used for keyless entry systems, pointing out that thieves have been using RF relay based attacks which access the real key for that task for many years now. He goes on to address another concern, that the Flipper could be used to clone the RFID chip of a car key, and concludes that it can in the case of some very old vehicles whose immobilizers used simple versions of the technology, but not on anything recent enough to interest a car thief.

Of course, to many readers this will not exactly be news. But it’s still important, because perhaps some of us will have had to discuss this story with non-technical people who might be inclined to believe such scare stories. Being able to say “Don’t take it from me, take it from an automotive locksmith” might just help. Meanwhile there is still the concern of CAN bus attacks to contend with, something the manufacturers could have headed off had they only separated their on-board subsystems.

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A “Full” Keyboard For $5*

February 29, 2024 by 14 Comments

Sure, we’ve all seen PCB business cards at this point, but what about giving away a full-blown keyboard at meetups and such? That’s just how cost-effective the idawgz32 keyboard is. How on Earth can it cost so little? [sporewoh] used the CH552 microcontroller, which comes in around a dollar and only needs a couple of capacitors to get it up and running. The firmware is FAK.

As [sporewoh] writes in this blog post about the keyboard, they did some analysis and realized that most of the cost of their previous tiny board came from the switches. In addition to switching up the switches, [sporewoh] performed a few tricks to get the cost down, like making the key spacing 9 mm x 9 mm so that the overall board is less than 100 mm x 100 mm (which triggers a deal at a certain board house).

Unfortunately, the switches turned out not to be so good. They had greater travel and required more actuation force than the ones [sporewoh] was used to with previous board. The switches were also scratchy, which was solved with a little Krytox. But ultimately, they are pretty unreliable, so the next revision will use Panasonic EVQP0N02Bs.

If this seems familiar, you may be recalling this $3 macro pad which uses the same chip, or maybe the fact that we’ve covered the CH552 in detail.

*Thanks to the current CAD to USD exchange rate.