2 And USB To MSX

August 2, 2021 by Kristina Panos 9 Comments

Say what you will about suitcase computers, but at least most of them still have their keyboards with them. [danjovic] has this vintage Brazilian computer from the 1980s called a Gradiente Expert. These were MSX machines with Z80 chips that ran BASIC, DOS, and CP/M, and they looked like state-of-the-art dual-deck stereo systems. You can still find them pretty easily, but sadly, most of them have lost their rad mechanical keyboard with its giant arrow keys and proprietary connector.

If you now want to get one of these awesome pieces of computing history and would like to be able to talk to it, [danjovic] has you covered with the open-source EXPS/2 keyboard adapter. It will allow you to connect either a PS/2 keyboard or a USB keyboard in fallback mode to the Expert using an ATMega328P and a bespoke DIN-13 to DB-13 cable. As it turns out, there’s a wealth of information on MSX keyboard matrices out there.

How much do you know about the USB keyboard interface? If you want a warehouse of information delivered to your brain in the most pleasant way possible, go watch [Ben Eater] break it down with pen and paper.

Levitation By Sound

August 2, 2021 by Al Williams 12 Comments

Levitating things with magnets is no great feat these days. We don’t see as many projects with sonic levitation. However, Japanese engineers have a new method to lift objects using sound. The process isn’t totally reliable yet, but it may lead to better methods in the future. You can see a video about the work below.

Manipulating very small items via laser or acoustics isn’t new. However, there are significant limitations to current methods. This new approach uses an array of hemispherical ultrasound transducers. By controlling the amplitude and phase of each transducer, an acoustic trap forms and can pick up a 3 mm polystyrene ball without direct contact.

Manipulating objects without contact interests us for a few reasons, not the least of which is circuit assembly. Robust technology of this type could also add new dimensions to additive manufacturing. Of course, it is a long way from a 3 mm polystyrene ball to a surface mount component. However, you have to admit watching components just float through the air to their final resting places would be something to see.

Not that we haven’t seen sonic levitation before. Magnetic levitation tends to be easier, but also has some limitations.

Continue reading “Levitation By Sound” →

Dedicated LED Animation Framework For ESP32

August 2, 2021 by Danie Conradie 8 Comments

[Eric Arcana] has been creating animated holiday decorations for several years, which involved a lot of custom code to make things light up the way he wanted, pulling the microcontroller to make changes. Using ESP32s with remote software updates is easier, but [Eric] also wanted to make the code simpler. To achieve this he created Fade, a custom programming language/framework for controlling LED animations from the ESP32.

Fade is written for addressable RGB LEDs like the Neopixel/WS2812. It keeps track of the current color of every LED in the system and allows the user to define what color it should be at a specified time in the future. Time is specified using 10 ms clock cycles. The LEDs will smoothly change from one color to the other in the specified number of clock cycles, without needing to specify what the intermediate colors should be.

Code is written in simple IDE, running on a web server on the ESP32 itself, or on a remote Windows PC. The language is very simple, but still powerful enough to create complex LED animations. A key part of it is the ability to specify multiple concurrent state changes in just a few lines of code. [Eric] also included optioning to take touch button inputs and use them to update the animations. Another nice feature is a simulation window on the desktop IDE. It allows you to create custom LED layouts on PC, and test your code without needing to send it to the ESP32.

Addressable LEDs have made creating large LED installations a lot simpler, like this 6 foot LED ball or a LED Video Wall.

Continue reading “Dedicated LED Animation Framework For ESP32” →

Single-Wheel Motorcycle Trailer

August 2, 2021 by Danie Conradie 40 Comments

A motorbike might not take up a lot of parking space, but this is not true for the trailer required to transport one. To solve this problem, [Make It Extreme] built a custom single-wheel motorbike trailer barely wider than the motorcycle itself.

The frame of the trailer is welded together from a couple of sections of large diameter steel tube, with a single car wheel mounted to a C-shaped portion on the rear end. A standard ball hitch would allow the entire trailer to tilt over to one side, so a pin hitch is used instead, with a pivot to allow up and down movement. Another pivot was added to the frame just ahead of the rear wheel to allow the trailer to lower to the ground for loading. It is raised and lowered with a manually pumped hydraulic cylinder, and a small pivoting ramp at the back also acts as a stop for the motorbike’s rear wheel. With the rigid frame and no suspension, we’re just wondering how well it will handle bumps at high speed.

[Make It Extreme] really likes his recreational vehicles, which include a monotrack motorbike, a monowheel, and an all-terrain hoverboard, among others. Continue reading “Single-Wheel Motorcycle Trailer” →

Mag-Lev Switches Are The Future Of Clacking

August 2, 2021 by Kristina Panos 22 Comments

While there’s probably a Cherry MX clone born every year or so, it’s not often that such a radically different type of switch comes along. These “Void” switches are Hall-effect magnetic levitation numbers devised by keyboard connoisseur and designer [riskable]. Can you imagine how satisfying it is to clack on switches that actuate with magnets? They have adjustable tactility and travel thanks to even more tiny magnets. But you won’t be able to get these in a group buy or anything. If you want some of these babies, [riskable] says you’ll have to print and assemble ’em yourself.

These attractive switches don’t have a Cherry MX footprint, either, so you’ll need some of [riskable]’s AKUs, or Analog Keyboard Units (YouTube) to actually use them. [riskable] predicts that unlike the switches, the AKUs will likely be available to buy at some point in the future. (Okay good, because we really would love to know what these feel like in a keyboard!)

So, how do they work? As explained in the first video embedded below, there is one magnet in the slider and another in the housing. These two are attracted to each other, so actuating the switch separates them, which is where the Hall effect comes in. A third magnet in the keycap acts as the levitator to help return the switch to open position. The tactility of these switches is determined by the thickness of the plastic between the two lovebird magnets, so you could totally dial that in to whatever you want, in addition to all the other customization that 3D printing affords.

Tour and Teardown

The inimitable [Chyrosran22] featured these mag-nificent switches in one of his teardown videos, which is embedded below. One of the things [riskable] sent was a tactility sampler that ranges from an unimaginably tactile 0.0 mm of plastic in between them to not quite 2 mm.

In case you’re wondering, the video is remarkably safe-for-work, which is surprising given the content creator’s propensity for long strings of creative and hyphenated curses. We suppose [Chyrosran22] saves that stuff for the bad keyboards, then.

Stick around after the rightfully glowing review for [riskable]’s tour of a hand-wired analog macro pad using these switches. When you have a few extra minutes, check out the video build journey of these switches on [riskable]’s YouTube channel.

So, would these switches make the clickiest keyboard ever? Maybe, but consider this striking solenoid setup.

Continue reading “Mag-Lev Switches Are The Future Of Clacking” →

AND!XOR’s DEF CON 29 Electronic Badge Is An Assembly Puzzle

August 2, 2021 by Mike Szczys 3 Comments

For years I’ve looked forward to seeing each new unofficial hardware badge that comes out of the #Badgelife powerhouse known as AND!XOR. A mix of new and interesting components, alternate-reality game, and memes, you never know what they’re going to throw down.

A bubble pack landed on my desk on Thursday with the newest offering, the AND!XOR electronic badge built for DEF CON 29, happening this weekend as a hybrid in-person and online conference. While each previous year upped the ante on complexity and manufacturing magic tricks, it’s no surprise considering the uncertainty of both the global pandemic and global chip shortage that they took a different tack. What we have here is a badge hacking puzzle that challenges you to just figure out how to put the thing together!

Continue reading “AND!XOR’s DEF CON 29 Electronic Badge Is An Assembly Puzzle” →

VTOL Tailsitter Flies With Quadcopter Control Software

August 2, 2021 by Danie Conradie 11 Comments

Quadcopters are great for maneuverability and slow, stable flight, but it comes at the cost of efficiency. [Peter Ryseck]’s Mini QBIT quadrotor biplane brings in some of the efficiency of fixed-wing flight, without all the complexity usually associated with VTOL aircraft.

The Mini QBIT is just a 3″ mini quadcopter with a pair of wings mounted below the motors, turning it into a “tailsitter” VTOL aircraft. The wings and nosecone attach to the 3D printed frame using magnets, which allows them to pop off in a crash. There is no need for control surfaces on the wings since all the required control is done by the motors. The QBIT is based on a research project [Peter] was involved in at the University of Maryland. The 2017 paper states that the test aircraft used 68% less power in forward flight than hovering.

(Editor’s Note: [Peter] contacted us directly, and he’s got a newer paper about the aircraft.)

Getting the flight controller to do smooth transitions from hover to forward flight can be quite tricky, but the QBIT does this using a normal quadcopter flight controller running Betaflight. The quadcopter hovers in self-leveling mode (angle mode) and switches to acro mode for forward flight. However, as the drone pitches over for forward flight, the roll axis becomes the yaw axis and the yaw axis becomes the reversed roll axis. To compensate for this, the controller set up to swap these two channels at the flip of a switch. For FPV flying, the QBIT uses two cameras for the two different modes, each with its own on-screen display (OSD). The flight controller is configured to use the same mode switch to change the camera feed and OSD.

[Peter] is selling the parts and STL files for V2 on his website, but you can download the V1 files for free. However, the control setup is really the defining feature of this project, and can be implemented by anyone on their own builds.

For another simple VTOL project, check out [Nicholas Rehm]’s F-35 which runs on his dRehmFlight flight control software. Continue reading “VTOL Tailsitter Flies With Quadcopter Control Software” →