Right away, the build is somewhat reminiscent of a stringed instrument, what with its buttons laid out in four “strings” of six “frets” each. Only, they’re not so much buttons, as individual sections of a capacitive touch controller. A Raspberry Pi Pico 2 is responsible for reading the 24 pads, with the aid of two MPR121 capacitive touch ICs.
The Diapasonix can be played as an instrument in its own right, using the AMY synthesis engine. This provides a huge range of patches from the Juno 6 and DX7 synthesizers of old. Onboard effects like delay and reverb can be used to alter the sound. Alternatively, it can be used as a MIDI controller, feeding its data to a PC attached over USB. It can be played in multiple modes, with either direct note triggers or with a “strumming” method instead.
If you get a chance to visit a computer history museum and see some of the very old computers, you’ll think they took up a full room. But if you ask, you’ll often find that the power supply was in another room and the cooling system was in yet another. So when you get a computer that fit on, say, a large desk and maybe have a few tape drives all together in a normal-sized office, people thought of it as “small.” We’re seeing a similar evolution in particle accelerators, which, a new startup company says, can be room-sized according to a post by [Charles Q. Choi] over at IEEE Spectrum.
Usually, when you think of a particle accelerator, you think of a giant housing like the 3.2-kilometer-long SLAC accelerator. That’s because these machines use magnets to accelerate the particles, and just like a car needs a certain distance to get to a particular speed, you have to have room for the particle to accelerate to the desired velocity.
A relatively new technique, though, doesn’t use magnets. Instead, very powerful (but very short) laser pulses create plasma from gas. The plasma oscillates in the wake of the laser, accelerating electrons to relativistic speeds. These so-called wakefield accelerators can, in theory, produce very high-energy electrons and don’t need much space to do it.
Cycloidal drives have an entrancing motion, as well as a few other advantages – high torque and efficiency, low backlash, and compactness among them. However, much as [Sergei Mishin] likes them, it can be difficult to 3D-print high-torque drives, and it’s sometimes inconvenient to have the input and output shafts in-line. When, therefore, he came across a video of an industrial three-ring reducing drive, which works on a similar principle, he naturally designed his own 3D-printable drive.
The main issue with 3D-printing a normal cycloidal drive is with the eccentrically-mounted cycloidal plate, since the pins which run through its holes need bearings to keep them from quickly wearing out the plastic plate at high torque. This puts some unfortunate constraints on the size of the drive. A three-ring drive also uses an eccentric drive shaft to cause cycloidal plates to oscillate around a set of pins, but the input and output shafts are offset so that the plates encompass both the pins and the eccentric driveshaft. This simplifies construction significantly, and also makes it possible to add more than one input or output shaft.
As the name indicates, these drives use three plates 120 degrees out of phase with each other; [Sergei] tried a design with only two plates 180 degrees out of phase, but since there was a point at which the plates could rotate just as easily in either direction, it jammed easily. Unlike standard cycloidal gears, these plates use epicycloidal rather than hypocycloidal profiles, since they move around the outside of the pins. [Sergei] helpfully wrote a Python script that can generate profiles, animate them, and export to DXF. The final performance of these drives will depend on their design parameters and printing material, but [Sergei] tested a 20:1 drive and reached a respectable 9.8 Newton-meters before it started skipping.
As technology marches on, gear that once required expensive lab equipment is now showing up in devices you can buy for less than a nice dinner. A case in point: those tiny displays originally sold as Nintendo amiibo emulators. Thanks to [ATC1441], one of these pocket-sized gadgets has been transformed into 2.4 GHz spectrum analyzer.
These emulators are built around the Nordic nRF52832 SoC, the same chip found in tons of low-power Bluetooth devices, and most versions come with either a small LCD or OLED screen plus a coin cell or rechargeable LiPo. Because they all share the same core silicon, [ATC1441]’s hack works across a wide range of models. Don’t expect lab-grade performance; the analyzer only covers the range the Bluetooth chip inside supports. But that’s exactly where Wi-Fi, Bluetooth, Zigbee, and a dozen other protocols fight for bandwidth, so it’s perfect for spotting crowded channels and picking the least congested one.
Flashing the custom firmware is dead simple: put the device into DFU mode, drag over the .zip file, and you’re done. All the files, instructions, and source are up on [ATC1441]’s PixlAnlyzer GitHub repo. Check out some of the other amiibo hacks we’ve featured as well.
Not only are pianos beautiful musical instruments that have stood the test of many centuries of time, they’re also incredible machines. Unfortunately, all machines wear out over time, which means it’s often not feasible to restore every old piano we might come across. But a few are worth the trouble, and [Emma] had just such a unique machine roll into her shop recently.
What makes this instrument so unique is that it’s among the first electric pianos to be created, and one of only three known of this particular model that survive to the present day. This is a Vivi-Tone Clavier piano which dates to the early 1930s. In an earlier video she discusses more details of its inner workings, but essentially it uses electromagnetic pickups like a guitar to detect vibrations in plucked metal reeds.
To begin the restoration, [Emma] removes the action and then lifts out all of the keys from the key bed. This instrument is almost a century old so it was quite dirty and needed to be cleaned. The key pins are lubricated, then the keys are adjusted so that they all return after being pressed. From there the keys are all adjusted so that they are square and even with each other. With the keys mostly in order, her attention turns to the action where all of the plucking mechanisms can be filed, and other adjustments made. The last step was perhaps the most tedious, which is “tuning” the piano by adjusting the pluckers so that all of the keys produce a similar amount or volume of sound, and then adding some solder to the reeds that were slightly out of tune.
Back in the mid 1990s, the release of Microsoft’s Windows 95 operating system cemented the Redmond software company’s dominance over most of the desktop operating system space. Apple were still in their period in the doldrums waiting for Steve Jobs to return with his NeXT, while other would-be challengers such as IBM’s OS/2 or Commodore’s Amiga were sinking into obscurity.
Into this unpromising marketplace came Be inc, with their BeBox computer and its very nice BeOS operating system. To try it out as we did at a trade show some time in the late ’90s was to step into a very polished multitasking multimedia OS, but sadly one which failed to gather sufficient traction to survive. The story ended in the early 2000s as Be were swallowed by Palm, and a dedicated band of BeOS enthusiasts set about implementing a free successor OS. This has become Haiku, and while it’s not BeOS it retains API compatibility with and certainly feels a lot like its inspiration. It’s been on my list for a Daily Drivers article for a while now, so it’s time to download the ISO and give it a go. I’m using the AMD64 version.
A Joy To Use, After A Few Snags
If you ignore the odd font substitution in WebPositive, it’s a competent browser.
This isn’t the first time I’ve given Haiku a go in an attempt to write about it for this series, and I have found it consistently isn’t happy with my array of crusty old test laptops. So this time I pulled out something newer, my spare Lenovo Thinkpad X280. I was pleased to see that the Haiku installation USB volume booted and ran fine on this machine, and I was soon at the end of the install and ready to start my Haiku journey.
Here I hit my first snag, because sadly the OS hadn’t quite managed to set up its UEFI booting correctly. I thus found myself unexpectedly in a GRUB prompt, as the open source bootloader was left in place from a previous Linux install. Fixing this wasn’t too onerous as I was able to copy the relevant Haiku file to my UEFI partition, but it was a little unexpected. On with the show then, and in to Haiku.
In use, this operating system is a joy. Its desktop look and feel is polished, in a late-90s sense. There was nothing jarring or unintuitive, and though I had never used Haiku before I was never left searching for what I needed. It feels stable too, I was expecting the occasional crash or freeze, but none came. When I had to use the terminal to move the UEFI file it felt familiar to me as a Linux user, and all my settings were easy to get right.
Never Mind My Network Card
If only the network setup on my Thinkpad was as nice as the one in the VM.
I hit a problem when it came to network setup though, I found its wireless networking to be intermittent. I could connect to my network, but while DHCP would give it an IP address it failed to pick up the gateway and thus wasn’t a useful external connection. I could fix this by going to a fixed IP address and entering the gateway and DNS myself, and that gave me a connection, but not a reliable one. I would have it for a minute or two, and then it would be gone. Enough time for a quick software update and to load Hackaday on its WebPositive web browser, but not enough time to do any work. We’re tantalisingly close to a useful OS here, and I don’t want this review to end on that note.
The point of this series has been to try each OS in as real a situation as possible, to do my everyday Hackaday work of writing articles and manipulating graphics. I have used real hardware to achieve this, a motley array of older PCs and laptops. As I’ve described in previous paragraphs I’ve reached the limits of what I can do on real hardware due to the network issue, but I still want to give this one a fair evaluation. I have thus here for the first time used a test subject in a VM rather than on real hardware. What follows then is courtesy of Gnome Boxes on my everyday Linux powerhouse, so please excuse the obvious VM screenshots.
This One Is A True Daily Driver
There’s plenty of well-ported software, but nothing too esoteric.
With a Haiku install having a working network connection, it becomes an easy task to install software updates, and install new software. The library has fairly up-to-date versions of many popular packages, so I was easily able to install GIMP and LibreOffice. WebPositive is WebKit-based and up-to-date enough that the normally-picky Hackaday back-end doesn’t complain at me, so it more than fulfils my Daily Drivers requirement for an everyday OS I can do my work on. In fact, the ’90s look-and-feel and the Wi-Fi issues notwithstanding, this OS feels stable and solid in a way that many of the other minority OSes I’ve tried do not. I could use this day-to-day, and the Haiku Thinkpad could accompany me on the road.
There is a snag though, and it’s not the fault of the Haiku folks but probably a function of the size of their community; this is a really great OS, but sadly there are software packages it simply doesn’t have available for it. They’ve concentrated on multimedia, the web, games, and productivity in their choice of software to port, and some of the more esoteric or engineering-specific stuff I use is unsurprisingly not there. I can not fault them for this given the obvious work that’s gone into this OS, but it’s something to consider if your needs are complex.
Haiku then, it’s a very nice desktop operating system that’s polished, stable, and a joy to use. Excuse it a few setup issues and take care to ensure your Wi-Fi card is on its nice list, and you can use it day-to-day. It will always have something of the late ’90s about it, but think of that as not a curse but the operating system some of us wished we could have back in the real late ’90s. I’ll be finding a machine to hang onto a Haiku install, this one bears further experimentation.
Looking for an educational microcontroller board to get you or a loved one into electronics? Consider the tinyCore – a small and nifty octagon-shaped ESP32 board by [MR. INDUSTRIES], simplified for learning yet featureful enough to offer plenty of growth, and fully open.
The tinyCore board’s octagonal shape makes it more flexible for building wearables than the vaguely rectangular boards we’re used to, and it’s got a good few onboard gadgets. Apart from already expected WiFi, BLE, and GPIOs, you get battery management, a 6DoF IMU (LSM6DSOX) in the center of the board, a micro SD card slot for all your data needs, and two QWIIC connectors. As such, you could easily turn it into, say, a smartwatch, a motion-sensitive tracker, or a controller for a small robot – there’s even a few sample projects for you to try.
You can buy one, or assemble a few yourself thanks to the open-source-ness – and, to us, the biggest factor is the [MR.INDUSTRIES] community, with documentation, examples, and people learning with this board and sharing what they make. Want a device with a big display that similarly wields a library of examples and a community? Perhaps check out the Cheap Yellow Display hacks!
