Wireless networking is all-pervasive in our modern lives. Wi-Fi technology lives in our smartphones, our laptops, and even our watches. Internet is available to be plucked out of the air in virtually every home across the country. Wi-Fi has been one of the grand computing revolutions of the past few decades.
It might surprise you to know that Australia proudly claims the invention of Wi-Fi as its own. It had good reason to, as well— given the money that would surely be due to the creators of the technology. However, dig deeper, and you’ll find things are altogether more complex.
Usually, if something is tiny, it’s probably pretty cute to boot. [Luke J. Barker]’s lunar navigation game is no exception to this unwritten rule. And as far as contest rules go, this one seems to fit rather nicely, as it is tiny on more than one level.
Moon Base P (for Puppies) is built upon a XIAO ESP32-C3, an SSD1306 OLED display, and a single button to keep the BOM tidy. In this riveting side-scroller which sort of marries Lunar Lander and Flappy Bird, the top bar is always yellow and displays fuel and such, and the bottom is a rough, blue lunar surface over which you must maneuver your lunar lander. Keep pressing the button to stay up and avoid mountains, or let off the gas to cool the engine.
Fly that thing over the terrain, avoiding stray meteors and picking up free fuel, and then land gently at Moon Base P to save the stranded puppies. But you must keep flying — touch down anywhere but where you’re supposed to, and it’s game over! Once you’ve picked up the puppies, you must fly them safely onward to the rescue pod in order to win. Don’t miss the walk-through and demo after the break.
While track pads and mice dominate the pointing device landscape today, there was a time when track balls were a major part of the scene. In order to really sell the retro chops of his portable computer, [Ominous Industries] designed a clip-on style track ball for his retro Raspberry Pi laptop.
Starting with a half circle shape, he designed the enclosure in Fusion360 to house the guts of a USB trackball. Using the pattern along a path feature of the software, he was able to mimic the groovy texture of the main device on the trackball itself. Flexures in the top of the track ball case with pads glued on actuate the buttons.
We appreciate the honesty of the cuts showing how often the Pi can get grumpy at the extra wide display in this video as well as the previous issues during the laptop build. The bezel around the screen is particularly interesting, being affixed with magnets for easy access when needing to work on the screen.
When the electric guitar was first produced in the 1930s, there was some skepticism among musicians as to whether or not this instrument would have lasting impact or be a flash-in-the-pan novelty. Since this was more than a decade before the invention of the transistor, it would have been hard then to imagine the possibilities that a musician nowadays would have with modern technology to shape the sound of an instrument like this. People are still innovating in this space as well as new technology appears, like [Gary Rigg] who has added a few extra degrees of freedom to a guitar effects pedal.
A traditional expression pedal, like a wah-wah pedal, uses a single motion to change an aspect of the sound of the guitar, and is generally controlled with the musician’s foot. [Gary]’s pedal, on the other hand, can be manipulated in three different ways to control separate elements of the instrument’s sound. It can be pitched forward and back like a normal effects pedal, but also rolled side-to-side and twisted around its yaw axis. The pedal has a built-in IMU to measure the various position changes of the pedal, which is then translated by an RP2040 microcontroller to a MIDI signal which controls the three different aspects of the sound digitally.
While the yaw motion might be difficult for a guitarist to create with their foot while playing, the idea for this pedal is still excellent. Adding in a few more degrees of freedom gives the musician more immediate control over the sound of their instrument and opens up ways of playing that might not be possible or easy with multiple pedals, with the MIDI allowing for versatility that might not be available in many analog effects pedals. Not every pedal needs MIDI though; with the help of a Teensy this digital guitar pedal has all its effects built into a self-contained package.
Over at the Usagi Electric farm, [David Lovett]’s custom 1-bit, vacuum tube-based computer (UEVTC for short) has been coming along well the past years, matching and exceeding the Motorola MC14500B 1-bit industrial control unit (ICU) that it is heavily inspired by. What is still missing, however, is a faster way to get data into the computer than manually toggling switches. The obvious choice is to make a (punched) paper tape reader, but how does one go about this, and what options exist here? With a few historical examples as reference and the tape reader on the impressive 1950s Bendix G-15 which [David] happens to have lounging around, [David] takes us in a new video through the spiraling complexity of what at first glance seems like a simple engineering challenge.
Photodiodes in the tape reader of the Bendix G-15. (Credit: David Lovett, Usagi Electric)
Punched paper tape saw significant use alongside punched paper cards and magnetic tape, and despite their low bit density, if acid-free paper (or e.g. mylar) is used, rolls of paper tape should remain readable for many decades. So how to read these perforations in the paper? This can be done mechanically, or optically, with in both case the feedrate an important consideration.
Right off the bat the idea of a mechanical reader was tossed out due to tape wear, with [David] digging into his stack of photodetector tubes. After looking at a few rather clunky approaches involving such tubes, the photodiodes in the Bendix G-15’s tape reader were instead used as inspiration for a design. These are 1.8 mm diameter photodiodes, which aren’t super common, but have the nice property that they align exactly with the holes in the paper tape.
This left building a proof-of-concept on a breadboard with some incandescent bulbs and one of the photodiode to demonstrate that a valid logic signal could be produced. This turned out to be the case, clearing the construction of the actual tape reader, which will feature in upcoming videos.
We love it when we find someone on the Internet who has the exact same problem we do and then solves it. [Hyperspace Pirate] starts a recent video by saying, “Oh no! I need to get rid of the algae in my pond, but I bought too much algaecide. If only there were a way to turn all this excess into CNC machined parts.” OK, we’ll admit that we don’t actually have this problem, but maybe you do?
Algaecide is typically made with copper sulfate. There are several ways to extract the copper, and while it is a little more expensive than buying copper, it is cost-competitive. Electrolysis works, but it takes a lot of power and time. Instead, he puts a more reactive metal in the liquid to generate a different sulfate, and the copper should precipitate out.
Diamonds are nearly perfect crystals, but not totally perfect. The defects in these crystals give the stones their characteristic colors. But one type of defect, the NV — nitrogen-vacancy — center, can hold a particular spin, and you can change that spin with the correct application of energy. [Asianometry] explains why this is important in the video below.
Interestingly, even at room temperature, an NV center stays stable for a long time. Even more importantly, you can measure the spin nondestructively by detecting light emissions from the center.
