The Casio F-91W digital watch is perhaps one of the most successful pieces of consumer electronics ever made, having quietly supplied the essential function of an inexpensive and accurate LCD digital timepiece for many decades. As a result it has a huge following, and we’ve seen plenty of projects based upon it. [Matteo P] has one that we think you’ll like, he’s turned his Casio into a contactless payment device. We missed it when it came out, but sometimes a good project needs sharing.
If you’re a long-time Hackaday reader you may remember our investigation of 13.56 MHz NFC cards in which we showed you a disassembled card in which he antenna was a tuned circuit covering most of the card, with a small coupling coil for the chip. It’s this kind of card he uses, and ends up with an SLA printed front face for the watch that places the chip above the display and puts a pick-up coil around the outside. The most interesting part of the write-up though isn’t in the build, instead it’s the deep-dive into designing the RF parts and ensuring a good coupling at something close to resonance. Read it, if you fancy trying NFC-enabling any other random items.
Using the special pens to remove the wax coating on the template. (Credit: Old Typerwriters and Calculators, YouTube)
Document duplication has been a highly desirable feature, long before medieval monks slaved over yet another illuminated manuscript by flickering candle light. Fortunately one part of the Industrial Revolution was the invention of machines like Cyclostyle copying machines, which covered a range of manual and automated devices. One such crank-powered device from 1890 is demonstrated in this video.
The Cyclostyle and neo-Cyclostyle copying system was quite simple yet elegant: by removing the wax coating on a special piece of paper ink from a screen-printing system could be pressed through the resulting template, and allow for repeat copies to be made.
With the machine demonstrated in the video the ink is applied to the top rollers, with the lower roller inking itself on them during the retraction cycle, before applying the fresh ink to the screen on the cycle following the insertion of a fresh piece of paper to print on. With this method many copies of the design on the waxed template could be made before it had to be replaced, which would have saved countless hours of work by artists.
After the machine in the video more advanced designs were developed, some of which we covered previously. These would automate more parts of the process, making it faster and more precise, before being replaced by newer technologies.
It’s arguably adult-sized. (Credit: Sam Barker, YouTube)
A staple of old movies featuring railways, many handcars – also called pump trolleys or pump cars – feature the characteristic seesawing beam. Requiring at least two people, the motion of this beam is subsequently converted into the rotating motion of the wheels, propelling it at a leisurely pace across the tracks. As a fun and yet functional mechanical contraption it also makes for an entertaining 3D printable project, which is what [Sam Barker] and [Tom] did.
You can find the entire project over at Printables if you are feeling the itch as well, though as of writing details on the required bolts and shafts are still pending.
Since the entire assembly had to be lugged over to the Open Sauce event in the US, they had to design it to be small enough to fit into check-in luggage and easy enough to reassemble in a hotel room. Naturally this put some constraints on the full size of the contraption, with it omitting compatibility with standard gauge railways and also being decidedly fun-sized.
That said, it seems to have left an impression on the folk over at Open Sauce, and it’s hard to argue with the sheer fun factor of such a co-op mode of transportation. Even if bicycle-style handcars are more popular these days, especially for tourist purposes, the old seesaw-style has that certain charm to it.
We’ll start this week off with some disappointing, though not entirely unexpected, news — the ambitious commercial mission to save NASA’s Neil Gehrels Swift Observatory is officially a bust. The space agency provided an update earlier this week explaining that the attitude control issues with the LINK spacecraft that started a few weeks after it launched will prevent it from being able to safely dock with the Swift Observatory and boost its altitude. As such, the space telescope is now expected to reenter the Earth’s atmosphere and burn up before the end of the year.
Although LINK won’t be able to live up to its name, NASA did say operator Katalyst Space has been given permission to continue with the rendezvous attempt. The two craft won’t actually make contact with each other, but teams on both sides feel there’s lessons to be learned and data to be collected by seeing the orbital dance of these two vehicles play out for as long as possible.
Speaking of hardware that couldn’t quite hit its design goals, TechCrunch is reporting that a class action lawsuit has been filed against Oura by customers that say the company made misleading claims about the sleep-tracking accuracy of their smart rings. Namely, that the rings could somehow detect which stage of sleep the wearer was in with only the pulse and temperature sensors it has onboard.
After previously putting a very basic version of Minecraft on the Game Boy Color, [Tobi] decided to have some fun and port that version also to the Super Nintendo (SNES), just to see what would happen with its more powerful hardware. Even without using an add-on chip like the Super FX 3D chip that made games like Star Fox and Doom possible with its 3D-rendered geometry, the basic SNES hardware can already provide a serviceable Minecraft experience.
You can download the SFC file here, featuring a starting world in which you can do all the usual Minecraft-ing shenanigans, like world destruction and construction. Unsurprisingly the game’s resolution is much higher than on the GBC, though the brief glimpse [Tobi] shows of Minecraft on the Game Boy Advance (GBA) with its proper 3D-rendering hardware are leaps ahead of what the basic SNES can do.
This of course raises the question of what Minecraft on the SNES could look like once you add the Super FX or similar 3D accelerator chips for the SNES into the mix. Rather than just being limited to sprite-based graphics and transformations, suddenly you can use real polygons.
Impressive as it most certainly is when an amateur fabricates a semiconductor, most of the projects we’ve seen are more demonstrations than workable chips. [Dr. Semiconductor], however, is going much further with his fabrication process, and is already working on a method to bond chips to printed circuit boards. It’s difficult to align a PCB with the pads on the underside of an opaque silicon wafer, however, so as a trial run he’s made and bonded some transparent LED chips.
The starting material for these chips is a gallium nitride (GaN) LED epiwafer, a stacked structure of n-doped GaN, an indium gallium nitride quantum well layer, and p-doped GaN grown on a sapphire substrate. When current passes through the structure, electrons from the n-doped layer and holes from the p-type layer recombine in the quantum well layer, emitting blue light. To make a functional LED from this, [Dr. Semiconductor] needed to make electrical contacts to both the n-type and p-type layers. Making the n-type contact required cutting through the p-type and quantum well layers.
This would normally be done with reactive ion etching in chlorine, but [Dr. Semiconductor] came up with a new process: a 355-nm ultraviolet etching laser causes GaN to break down into gallium and nitrogen, with the resulting cut being cleaned up by a potassium hydroxide etch. To deposit the contacts themselves, [Dr. Semiconductor] formed a photoresist mask, deposited metal (nickel, silver, and titanium) in a sputtering chamber, and used a developer solution to dissolve the mask and lift off the unwanted metal regions.
The LED after bonding and phosphor application.
When [Dr. Semiconductor] applied current between the two contacts, the LED glowed bright blue. The next step was to mount it to a PCB; to do so, he first sliced the wafer into individual LED chips with the ultraviolet laser. He then electroplated indium bumps onto a printed circuit board, positioned the chip above these bumps, added some rosin flux, and melted the indium bumps. This soldered the chip to the board and let the board power the LED.
Like most commercial LEDs, these were blue; most LED assemblies additionally include a phosphor layer which absorbs blue light and emits another color. To create a white LED, for example, [Dr. Semiconductor] mixed cerium-doped yttrium aluminium garnet phosphor powder with clear silicone and spread it over the LED. This absorbs some of the blue light and emits yellow light, and the resulting mixture of blue and yellow light looks white to human eyes.
There’s no actual data, but if we had to guess the least-favourite Disney movie of former Amiga owners would have to be Frozen, because none of them will ever be able to “Let it Go”. The Amiga-derived AROS Research Operating System has just been ported to boot bare-metal on the Raspberry Pi, in both 32-bit and 64-bit versions. Yes, there’s a 64-bit Amiga-compatible OS that runs on ARM. It truly is a time of wonders.
AROS has already been ported to a number of platforms. Besides x86, there’s a PPC port that provided a lot of code to the MorphOS, which you can read about here, and a back-port that brings AROS back to original Amiga 68k hardware. There is even a build for RISC V.
AROS developers are making sure that Amiga legacy isn’t stuck on any given hardware, so they never have to let it go. So while not totally out of left field, this development is “pretty nifty” both in that it gives another ultralight operating system for the Pi, with boot times to rival RiscOS, and another platform for ex-Amiga users to play with that isn’t 40 years old. Previously if you wanted to run AROS on a Pi it was virtualized in Linux, making it similar to all other Amiga emulators.
While some software has been recompiled for ARM, the available software isn’t as full-featured as x86, but that’s almost certain to change as time goes on. It’s early days yet and this build is very much a work in progress. Likewise we expect support for other Pi boards to expand, as while right now the target is the Pi3, the forum threads include discussion of the Pi4 and even Zero2W.
You can check the port out in action in a video by [Dan Wood] embedded below, sent to us by tipster [Stephen Walters]. Thanks [Stephen]!
