The story of how [Tony]’s three-wheeled electric scooter came to be has a beginning that may sound familiar. One day, he was browsing overseas resellers and came across a new part, followed immediately by a visit from the Good Ideas Fairy. That’s what led him to upgrade his DIY electric scooter to three wheels last year, giving it a nice speed boost in the process!
The part [Tony] ran across was a dual brushless drive unit for motorizing a mountain board. Mountain boards are a type of off-road skateboard, and this unit provided two powered wheels in a single handy package. [Tony] ended up removing the rear wheel from his electric scooter and replacing it with the powered mountain board assembly.
He also made his own Arduino-based interface to the controller that provides separate throttle and braking inputs, because the traditional twist-throttle of a scooter wasn’t really keeping up with what the new (and more powerful) scooter could do. After wiring everything up with a battery, the three-wheeled electric scooter was born. It’s even got headlights!
Visitors at the Garden D’Lights in Bellevue, Washington had a problem. While touring the holiday lights show, they kept straying off the path. The event organizers tried some simple LED arrows, but they were just more points of light among a sea filled with them. This is when [Eric Gunnerson] was asked to help out. He’s apparently had some experience with LED animations, even cooking up a simple descriptor language for writing animations driven by an ESP32. To make the intended path obvious, he turned to a PVC board with 50 embedded WS2812 pixels –RGB controllable LEDs. The control box was a USB power adapter and an ESP8266, very carefully waterproofed and connected to the string of pixels. The backer board is painted black, to complete the hardware. Stick around after the inevitable break, to get a look at the final
The description of the build process is detailed and contains some great tips, but without a clever LED animation, it’s still of questionable utility. The pattern chosen is great, with the LEDs being blue most of the time, and a flame-like gradient chasing through the arrow every couple seconds. It’s obviously different from the lights of the show, and seems to be a real winner. [Eric] has published his code, with the sheepish caveat that he had to reinvent the wheel once again, and couldn’t reuse any of his previous LED animation work on this one. It’s a simple hack, but a great build log, and an effective solution to a subtle problem. And if addressable LEDs are your thing, check out our other hacks!
In interaction designer [Leonardo Amico]’s work Processing Decay, lettuce is used as an input to produce sound as an element within a CMOS circuit.
We’ve all seen lemons and potatoes doubling in science-fairs as edible batteries, but lettuce is something else. [Leandro]’s circuit uses alligator clips to insert lettuce into oscillators in this audio generating circuit — we think they’re behaving like resistors. Without refrigeration, the resistance of the lettuce changes, and so does the oscillation in the circuit. In a matter of hours, days, and weeks the cells degrades slowly, modulating the system and its sonic output. What a way to make music!
[Ryan] decided that an OLED display was too expensive for something to hand out and an LED matrix too thick, so he decided to keep it simple and use an array of 18 LEDs—9 in each of two colors laid out in a familiar 3×3 grid. An ATmega328p running the Arduino bootloader serves as the brains of the operation. To achieve a truly minimal design [Ryan] uses a single SMD pushbutton for control: a short press moves your selection, a longer press finalizes your move, and a several-second press switches the game to a single-player mode, complete with AI.
If you’d like to design a Tic-Tac-Toe business card for yourself, [Ryan] was kind enough to upload the schematics and code for his card. If you’re still pondering what kind of PCB business card best represents you, it’s worth checking out cards with an updatable ePaper display or a tiny Tetris game.
How does a TRS-80 even manage to output anything useful to these monitors? [Glen] wrote his own low-level driver in machine code to handle that. The driver even has useful routines that are callable from within BASIC, meaning that programs written on the TRS-80 are granted powerful drawing abilities. Oh, and did we mention that the VGA graphics cards themselves were designed and made by [Glen]?
Interested in making your own? [Glen] provides all the resources you’ll need to re-create his work, including machine code drivers and demonstration BASIC programs as downloadable audio files, just as they would have been on original cassette tapes.
Watch things in action in the videos embedded below. The first draws a Land Rover, and the second plots a simple Moiré pattern star. Not bad for 70s-era hardware and 74xx logic!
We recently ran an article on a sweet percussion device made by minimal-hardware-synth-madman [Gijs Gieskes]. Basically, it amplifies up an analog meter movement and plays it by slamming it into the end stops. Rhythmically, and in stereo. It’s got that lovely thud, plus the ringing of the springs. It takes what is normally a sign that something’s horribly wrong and makes a soundtrack out of it. I love it.
[Gijs] has been making electro-mechanical musical hacks for about as long as I’ve been reading Hackaday, if not longer. We’ve written up no fewer than 22 of his projects, and the first one on record is from 2005: an LSDJ-based hardware sequencer. All of his projects are simple, but each one has a tremendously clever idea at its core that comes from a deep appreciation of everything going on around us. Have you noticed that VU meters make a particular twang when they hit the walls? Sure you have. Have you built a percussion instrument out of it? [Gijs] has!
Maybe it’s a small realization, and it’s not going to change the world by itself, but I’ve rebuilt more than a couple projects from [Gijs]’ repertoire, and each one has made my life more fun. And if you’re a regular Hackaday reader, you’ve probably seen hundreds or thousands of similar little awesome ideas played out, and maybe even taken some of them on as your own as well. When they accumulate up, I believe they can change the world, at least in the sense of filling up a geek’s life. I hope that feeling comes across when we write up a project. Those of you out there hacking, we salute you!
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On no planet is making your own X-ray tube a good idea. But that doesn’t mean we’re not going to talk about it, because it’s pretty darn cool.
And when we say making an X-ray tube, we mean it — [atominik] worked from raw materials, like glass test tubes, tungsten welding electrodes, and bits of scrap metal, to make this dangerously delightful tube. His tool setup was minimalistic as well– where we might expect to see a glassblower’s lathe like the ones used by [Dalibor Farny] to make his custom Nixie tubes, [atominik] only had a small oxy-propane hand torch to work with. The only other specialized tools, besides the obvious vacuum pump, was a homebrew spot welder, which was used to bond metal components to the tungsten wires used for the glass-to-metal seals.
Although [atominik] made several versions, the best tube is a hot cathode design, with a thoriated tungsten cathode inside a copper focusing cup. Across from that is the anode, a copper slug target with an angled face to direct the X-rays perpendicular to the long axis of the tube. He also included a titanium electrode to create a getter to scavenge oxygen and nitrogen and improve the vacuum inside the tube. All in all, it looks pretty similar to a commercial dental X-ray tube.
The demonstration in the video below is both convincing and terrifying. He doesn’t mention the voltage he’s using across the anode, but from the cracking sound we’d guess somewhere around 25- to 30 kilovolts. The tube really gets his Geiger counter clicking.