When the microcomputer first landed in homes some forty years ago, it came with a simple freedom—you could run whatever software you could get your hands on. Floppy disk from a friend? Pop it in. Shareware demo downloaded from a BBS? Go ahead! Dodgy code you wrote yourself at 2 AM? Absolutely. The computer you bought was yours. It would run whatever you told it to run, and ask no questions.
Today, that freedom is dying. What’s worse, is it’s happening so gradually that most people haven’t noticed we’re already halfway into the coffin.
[bogdanthegeek] has a lot of experience with the ARM platform, and their latest escapade into working with cheap ARM chips recovered from disposable vapes involved a realization that it was just plain wrong to debug such recovered silicon with something as expensive as a Pi Pico. No, they needed to build a debugger using the super cheap CH32V003.
What follows is an interesting tour around ARM Debug Access Port (DAP) programmers and creating a practical USB-connected device that actually works with modern toolchains. The first problem to be solved was that of host connectivity. These days, it’s USB or go home, which immediately limits the microcontrollers you can choose. Luckily for [Bogdan], they were aware of the excellent work by [cnlohr] on wedging low-speed USB support onto the RISC-V CH32v003 with the software-only bit-banging rv003usb, which provided a starting point. The next issue was to check for interrupt-driven endpoint support (needed for low-speed USB) in the Mac OS X kernel, which they knew was being dropped at an alarming rate (well, at least for full-speed). Luckily, the CMSIS-DAP standard required support for interrupt-driven USB endpoints, so kernel support was likely intact.
Next, [Bogdan] noticed that the DAPLink project had been ported to the bigger, native-USB WCH chips like the CH32V203, so it was a matter of porting this code to the diminutive CH32V003 using the rv003usb stack for the USB support using [cnlohr]’s ch32fun toolchain. There were a few bumps along the way with a lack of clarity in the DAPLink code, and some inconsistencies (across platforms) with the USB library dependencies of the upstream tool pyOCD, but they did get some tools working on at least Mac OS and some others on Linux. Which was nice.
LED billboards are cyberpunk-dystopian enough for most, but it can get worse. For example, this project by [Concept Crafted Creations] that takes the whole concept and takes it airborn (literally) in the form of a flying POV sphere called “Zippy”.
We love persistence-of-vision (POV) displays, and have featured plenty before, from the very complicated to the fairly simple. The idea is simple: take one or more rings of LEDs and spin them rapidly enough that the persistence-of-vision effect creates a solid image in your visual field. We covered the basics years back. “Zippy” has one ring of addressable LEDs that surrounds the thing that makes it unique: the quadcopter at its core. None of those other projects could fly, after all.
You might imagine a big, spinning ring is going to have a lot of torque to cancel out, and that is true — about 2.3 kgf — and it led to a lot of prototypes crashing early on. After trying to use flaps to direct the downwash of the quadcopter rotors to counter the spin, [Concept Crafted Creations] eventually added two extra props for yaw control, and that seemed to do the trick. We say “quadcopter” because that’s the configuration, but Zippy ended up heavy and needs eight lift motors to fly. PVC pipe and PLA aren’t the lightest build materials, after all. That’s ten props, total, plus another outrunner to spin the POV ring. All those motors, plus the current draw of the LEDs means the flight time might not impress — but Zippy sure does, at last as long as the batteries hold out.
There’s something eye-catching about POV displays, and seeing this one drifting upwards like Kang and Kodos decided to steal the Los Vegas Sphere is even more arresting. That made the crash at the end of the video sad to see, but [Concept Crafted Creations] hasn’t ruled out rebuilding it if his viewers show enough interest. So if you like what you see, head over to YouTube and leave an encouraging comment for him to try, try again. Continue reading “POV Globe Takes To The Skies”→
The chiptune music scene is largely rooted in the sounds of the original Nintendo Game Boy and the Commodore 64, while still welcoming a wide range of other hardware under its general umbrella. Still, few chip musicians show up to a gig hauling a PDP-1. That’s perhaps a shame, given that the 1950s era machine can produce beautiful music—as demonstrated by [Peter Samson] and [Joe Lynch].
The video demonstration was recorded at the Computer History Museum in Mountain View, California. [Peter Samson] is operating the PDP-1, which is running the Harmony Compiler—which allows the machine to play four individual voices. This is achieved by taking advantage of the PDP-1’s program flags, which are visible as six light bulbs on the control panel. Instructions can be used to turn these bulbs on and off. The Harmony Compiler works by switching the bulbs on and off fast enough to create audible square waves when the light bulb outputs are wired to a simple audio amplifier.
Using Harmony Compiler, [Joe] and [Peter] worked together to transcribe the song Olson by Boards of Canada to play on the PDP-1. The song is encoded on paper tape, and fed into the machine—which dutifully plays back the hauntingly beautiful melody.
If you’re interested in the code that achieved this, it’s blessedly available via Github. If you love stories about old computers playing music, we’ve got those too. Video after the break.
It is easy to write off Tinkercad as a kid’s toy. It is easy enough for kids to learn and it uses bright colors looking more like a video game than a CAD tool. We use a variety of CAD tools, but for something quick, sometimes Tinkercad is just the ticket. Earlier this year, Tinkercad got a sketch feature, something many other CAD programs have and, now, you can even revolve the sketch to form complex objects. Tinkercad guru [HL ModTech] shows you how in the video below.
It wasn’t long ago that we needed to cut an irregular shape out of an STL and we found the sketch feature whic was perfect for that purpose. If you’ve used other CAD tools, you’ll know that sketches are typically 2D shapes that get changed into a 3D shape. The traditional thing is to simply extrude it, so if you draw a circle in 2D, you get a cylinder.
Over on YouTube, [The Modern Rogue] created an interesting video showing a slide-rule-like encryption device called the Réglette. This was a hardware implementation of a Vigenère-like Cipher, technically referred to as a manual polyalphabetic substitution cipher. The device requires no batteries, is fully waterproof, daylight readable and easy to pack, making it really useful if you find yourself in a muddy trench in the middle of winter during a world war. Obviously, because it’s a slide rule.
Anyway, so how does this cipher work? Well, the ‘polyalphabetic’ bit infers the need for a key phrase, which is indeed the first thing all parties need to agree upon. Secondly, a number is required as a reference point. As you can see from the video, the sliding part of the device has letters of the alphabet, as well as numbers and a special symbol. The body has two series of numbers, with the same spacing as the central, sliding part. A second copy of the sliding part is also needed to slide in behind the first unit. This second copy is neatly stowed below the body during storage.
With each message letter, you lookup the corresponding cipher text number, then shift the slider to the next key phrase letter.
The cipher works by first aligning the starting letter of the (variable-length) key phrase with the reference number. Next, encode the first symbol from the cleartext message (the thing you want to encrypt). You simply look up the letter on the slide and read off either of the numbers next to it. Randomly selecting the left or right set adds an extra bit of strength to the code due to increased entropy. The number is the first symbol for your ciphertext (the thing you want to transmit to the receiver). Next, you move on to the next symbol in the cleartext message. Align the following letter of the key phrase with the reference number, look up the corresponding letter in the message, and transmit the following number onwards. When you run out of key phrase letters, you loop back to the start, and the cycle repeats.
The special symbol we mentioned earlier is not really a ‘blank’; it is a control symbol used to retransmit a new reference number with the existing setup. To change the reference number, the blank character is encoded and sent, followed by the latest reference number. When the blank symbol is received at the other end, the following code is used as the reference number, and the key phrase position is reset to point back to the first letter, restarting the cycle anew. Simple, yes. Effective? Well, not really by modern standards, but at the time of limited computing power (i.e. pen and paper, perhaps a mechanical calculator at best), it would have been sufficient for some uses for a couple of decades.
Why is this Vigenère-like? Well, an actual Vigenère cipher maps letters to other letters, but the Réglette uses numbers, randomly selected, adding entropy, as well as the control code to allow changing the cypher parameter mid-message. This makes it harder to attack; the original Vigenère was considered first-rate cryptography for centuries.
If you’d like to play along at home and learn some other simple ciphers, check this out. Kings and Queens of old frequently used cryptography, including the famous Queen Mary of Scots. Of course, we simply can’t close out an article on cryptography without mentioning the Enigma machine. Here’s one built out of Meccano!
The Razer Nari is a decent wireless headset, but it’s a little oddball—because it uses a bespoke USB dongle for pairing. This is all well and good if you’re using a supported configuration; plug it into a Windows PC, run the utility, and you’re good to go. If you’re a Linux user, though, you were out of luck—but [JJ] has just solved that problem.
The tool was created by reverse engineering the pairing protocol used by Razer’s own proprietary software. [JJ] figured out the necessary pairing command, and how to send it to both the dongle and the headset. The headset itself must be connected by a USB cable when initiating the pairing process.
[JJ] believes the tool should work with any Razer Nari and dongle variant. However, the Nari Ultimate and Nari Essential models are yet to be tested, with verification still required. However, the pairing commands were extracted from Razer’s own tool and don’t appear to differ so it should probably work across the board. Setup is still a little fussy, particularly to get both the Game Audio and Chat Audio outputs working under Linux. However, [JJ] has helpfully provided the necessary detail to get everything up and running with PulseAudio and PipeWire setups.
