The plethora of wireless communications technologies have cut the comms wire for many applications, but these devices still require power. For home automation, this might mean a battery or mains power, but there is also an alternative that we don’t see often: Kinetic power. [Bigclivecom] bought some kinetic switches from eBay and gave it his usual reverse engineering treatment.
True to the marketing, these switches do not require external power or a battery to send a wireless signal. Instead, it harvests energy from the magnetic latching action of the switch itself. When the switch is actuated, a small current is induced in a coil as the polarity of the magnetic field through its core changes rapidly. Through a series of diodes and resisters, the energy is stored in a capacitor, which is then used to power a small transmitter chip. The antenna coil is wrapped around the switch housing.
The receiver side is powered by mains and includes a relay output for lights. It would be really nice to have a hacker-friendly module for projects. We would be curious to see the range that these devices are capable of.
The same technology is used inside the Philips Hue Tap switch, of which Adafruit did a teardown a few years ago. If you want to learn more about RF modulation, check out the crash course article we put out a while back. Of course, the RTL SDR is an indispensable and affordable tool if you want to do some experimentation.
Back in the late 1980s, Commodore pulled the masterstroke of selling several models and generations of Amiga that were all powered by essentially the same speed 68000 and associated chipset. Sure, there were differences in the RAM and other options you could fit and later models had a few extra graphics modes. Still, the entry-level A500 did substantially the same as the high-end A2000. No matter, we the fans all wanted a 2000 anyway, though we typically found ourselves unable to afford one. It’s 2021 now though, so if you never achieved the dream of owning your own A2000, now you can build one of your own! It’s the task [Drygol] has taken on, with an A2000 made entirely from new components, save for a few salvaged Commodore-specific chips and connectors.
At its heart is a beautiful recreation of the original PCB that we’re guessing will be of great interest to owners whose NiCd batteries have leaked and corroded their originals. It’s all through-hole, but the sheer size of a motherboard still makes it a daunting prospect to solder by hand. There are a huge quantity of decoupling and ESD components that all have to be held with tape before the board is flipped over for soldering, and then all the chips are socketed. A Fat Agnes address generator was fitted on a RAM expansion daughterboard, leading to some significant problems as it proved not to be compatible and had to be removed.
The whole is put in a very low-profile PC case with appropriate risers for the Zorro slots, and then in goes a set of upgrades probably not seen in the same place since about 1993. We don’t recognize them all, but we can see accelerators, a floppy emulator, an HDD emulator using a CF card, and is that a network card we spy? This machine is still a work in progress, but we can guarantee it would have been an extreme object of desire thirty years ago. See it in action in the video below the break.
With many of the achievements of the Space Race now more than half a century behind us, it’s no wonder that we’re steadily losing the men who rode the rockets of the Mercury, Gemini, and Apollo programs into space. They were all very much in their primes at the time, but no matter what you’ve accomplished in life, even if it includes a trip to the Moon, time eventually catches up to you.
Still, it was quite a shock to learn today that astronaut Michael Collins passed away today at the age of 90. Collins made his trip to the Moon aboard Apollo 11, the mission which would see his crewmates Neil Armstrong and Edwin “Buzz” Aldrin descend to the surface in the Lunar Module Eagle and take the historic first steps on its surface in July of 1969.
When Nintendo officially ended production of the 3DS in September 2020, it wasn’t exactly a surprise. For one thing, some variation of the handheld system had been on the market since 2011. Which is not to say the product line had become stagnant: the system received a considerable mid-generation refresh, and there was even a more affordable variant introduced that dropped the eponymous stereoscopic 3D effect, but nearly a decade is still a fairly long life in the gaming industry. Of course Nintendo’s focus on the Switch, a hybrid device that blurs the line between console and handheld games, undoubtedly played a part in the decision to retire what could effectively be seen as a competing product.
While putting the 3DS out to pasture might have been the logical business move, a quick check on eBay seems to tell a different story. Whether it’s COVID keeping people indoors and increasing the demand for at-home entertainment, or the incredible library of classic and modern games the system has access to, the fact is that a used 3DS in good condition is worth more today than it was when it was brand new on the shelf this time last year.
I’ve certainly made more expensive mistakes.
In short, this was the worst possible time for me to decide that I finally wanted to buy a 3DS. Then one day I noticed the average price for a Japanese model was far lower than that of its American counterpart. I knew the hardware was identical, but could the firmware be changed?
An evening’s worth of research told me the swap was indeed possible, but inadvisable due to the difficulty and potential for unexpected behavior. Of course, that’s never stopped me before.
So after waiting the better part of a month for my mint condition 3DS to arrive from the land of the rising sun, I set out to explore the wide and wonderful world of Nintendo 3DS hacking.
There was a time when a Vector Network Analyser or VNA was the type of instrument that cost as much as a very fancy car or even a small house. The advent of commodity semiconductors that perform at high RF frequencies coupled with microcontrollers powerful enough to handle the data acquisition and processing might not yet have put those high-perfomance instruments within reach, but at our end of the market it’s opened the possibilities for some useful yet affordable devices. A fresh contender comes from [Jankae], whose LibreVNA tops out at 6 GHz and shows some significant attention to design detail that puts it above some of the budget offerings.
At its heart is the versatile Si5351 multi-way clock generator, accompanied by a pair of MAX2871 phase-locked-loop chips for the higher frequency local oscillators. A switched bank of low-pass filters take care of local oscillator harmonics, and in the receive chain there are ADL5081 mixers feeding a dual conversion IF running at 70 MHz and then 300 kHz. Finally the ADCs are Microchip’s MCP3313, and all is kept in sync by an FPGA and an STM32G431 microcontroller. The main data proccessing is offloaded to a host computer, with a software package and GUI able to be compiled on Windows, Linux, and OSX.
The PCB shows the attention to detail, not least in the power supply arrangements, with every major component receiving its own regulator to ensure no RF makes it down the power rails. It’s clear that a properly made LibreVNA won’t be as cheap as some of its rivals, but we think the corresponding performance hike would make the extra cost worthwhile.
There’s a document I had to sign to wrap up a community responsibility in rural Oxfordshire. At the bottom, dotted lines for signature and date. My usual illegible scrawl for a signature, and scribble in the date below it. Then there’s the moment when the lady handling the form scans it with a puzzled face for a minute, before accepting it with a smile. She’s just been ISO’d!
I’m telling you, you’ve got Pi Day wrong. Evan Shelhamer, CC BY 2.0.
Where I come from in England, it’s the norm to represent dates in ascending order: day, month, year. Thus the 4th of March 2021 becomes 04/03/2021 when written down on a form. This is entirely logical, and makes complete sense given the way a date is said aloud in English and other languages.
Meanwhile in America it’s the norm to represent dates in a different manner: month, day, year. Thus March 4th, 2021 becomes 03/04/2021 when written down on a form. This is also entirely logical, and makes complete sense given the way dates are pronounced in American English.
As someone whose job entails crossing the Atlantic in linguistic terms, I am frequently confused and caught out by this amusing quirk of being divided by a common language. Is 03/04/2021 the 3rd of April or March 4th? “Why can’t Americans use a logical date format!” I cry as in a distant transatlantic echo I hear my friends over there bemoaning our annoying European ways. It’s doubtful that this divergence has caused any satellites to crash, but it sure can be annoying.
Confusing Everyone For Over Three Decades
So I took a stand. A couple of decades ago I adopted ISO 8601 in writing dates, an international standard that’s been with us for well over three decades. It too is an entirely logical way to express time, but unlike the two mentioned earlier it’s not tied to any linguistic quirks. Instead it starts with the largest unit and expresses a date or time in descending order, and extends beyond dates into time. Thus the date on my form that caused the puzzlement was 2021-03-04. I’m guessing that here at Hackaday I’m preaching to the choir as I certainly won’t be the only one here using ISO 8601 in my daily life, but while we’re talking about alternative date formats within our community it’s an opportunity to take stock of the situation.
UNIX time is probably the most instantly recognisable of all our measurement schemes, being a count of seconds elapsed since the Unix epoch of 1970-01-01T00:00:00+00:00 UTC. Coincidentally this is also an auspicious date for many readers, as it’s our birthday. If I’d written the 4th of March on that form as 1614816000 though I would have been met with complete incomprehension, so aside from the occasional moment of coming together to observe a rollover it’s not something we use outside coding.
But it does lead neatly to another question: since UNIX time is most often expressed in text as a base-10 number, why on earth does our clock time work in base 60 for seconds, base 12 or 24 for hours, and then base 12 for months? Why don’t we use a base 10 metric time system?
It makes sense for our annual calendar and the length of our day to be derived from Earth’s orbit, as we use dates as a measure of season and times as a measure of the daily progress rather than simply elapsed periods. We owe our twelve-hour days and nights to the ancient Greeks and our 60 seconds and minutes to the ancient Babylonians, while our twelve months come from the ancient Romans. It’s clear that a 365.24-day year with four seasons doesn’t divide neatly into ten months, so we’re at the mercy of our own set of celestial bodies when talking about dates. But surely we could move on from ancient Greece and Babylon when it comes to the time of day?
Liberté, Égalité, Ponctualité!
A 10-digit Revolutionary French clock. DeFacto, CC BY-SA 4.0
Probably the most famous attempt at a decimal calendar came in the aftermath of the French Revolution; the French Republican calendar perhaps wisely stuck with twelve months but made each of them of three 10-day weeks, and then split the day by 10 hours, with each further subdivision being by base 10. The months each had 30 days, with the remaining 5 days (or 6 in leap years) being public holidays.
It came to an official end when the revolutionary government that had introduced it was replaced by that of Napoleon. Unlike other French Republican measurements such as the meter, it evidently didn’t provide enough advantage for its popularity to outlive its political origins.
There’s an interesting parallel in the decimalisation of British currency in 1971. Previously, a pound was 20 shillings, each of which were 12 pence. Afterwards, a pound became 100 new pence, and that’s stuck. Despite some people’s lingering nostalgia for the old system, the utility of decimialisation was self-evident.
The moral of the French time-decimalization story was that people simply use a calendar and time system to tell the date and time. When you need to do frequent arithmetic, as is the case with currency, distance, or weights, this is made significantly easier through decimals. But when nature hands you four seasons, you’re pressed into twelve months. Perhaps when we slip the bonds of Earth, we’ll use decimal Stardates, but in the mean-time, ISO might just be the way to go.
When you stop to think about the history of flight, it really is amazing that the first successful flight the Wright brothers made on a North Carolina beach to Neil Armstrong’s first steps on the Moon spanned a mere 66 years. That we were able to understand and apply the principles of aerodynamics well enough to advance from delicate wood and canvas structures to rockets powerful enough to escape from the gravity well that had trapped us for eons is a powerful testament to human ingenuity and the drive to explore.
Ingenuity has again won the day in the history of flight, this time literally as the namesake helicopter that tagged along on the Mars 2020 mission has successfully flown over the Red Planet. The flight lasted a mere 40 seconds, but proved that controlled, powered flight is possible on Mars, a planet with an atmosphere that’s as thin as the air is at 100,000 feet (30 km) above sea level on Earth. It’s an historic accomplishment, and the engineering behind it is worth a deeper look.
