PC gamers have the benefit of a broad ecosystem of peripherals built to serve their gaming pleasure. As a bonus, if there’s something out there that doesn’t work with the platform, someone is likely already selling an adapter for it. Console gamers aren’t so lucky, and the vast majority stick with the factory standard controller. [megavolt85] isn’t one of them however, and spun up a multi-adapter for the Sega Dreamcast.
The adapter lets the player use a huge variety of controllers with the Dreamcast. There’s support for both PS1 & PS2 controllers, including vibration support, as well as MegaDrive & Saturn pads, too. PS/2 mice and keyboards can be used as well, and up to 16 VMUs can be hooked up as well. The adapter uses the STM32F103C8T6 microcontroller, which runs at up to 72MHz, giving it plenty of grunt to emulate the Dreamcast’s Maple controller interface.
If you enjoy simulating circuits, you’ve probably used LTSpice. The program has a lot of powerful features we tend to not use, including the ability to make custom components that are quite complex. To illustrate how it works, [asa pro] builds a potentiometer component that is not only a good illustration but also a useful component.
The component is, of course, just two resistors. However, using parameters, the component gets two values, a total resistance and a percentage. Then the actual resistance values adjust themselves.
The development of the turbojet engine was a gamechanger in aviation, as no longer would aircraft designers have to struggle with ever larger and more complex piston engines, nor would propellers keep planes stuck below the speed of sound. However, the turbojet is an exacting device, demanding the utmost of materials in order to work successfully. [Integza] discovered just this in his quest to build one at home.
Unlike most home jet engine builds, this one doesn’t use a turbocharger or go with a simpler pulse jet design – though [Integza] has built those, too. This is a proper radial-flow turbojet design. The build uses a 3D-printed compressor, which is possible as it doesn’t have to deal with much heat. However, for the turbine, [Integza] realised that plastic wouldn’t cut it. After experiments with ceramic resins failed too, a 3D printed jig was instead built to allow sheet metal to easily be crafted into a workable turbine. Other internal components were made out of concrete for heat resistance, and a combustion chamber welded up out of steel.
The engine did run after several attempts, albeit for just ten seconds before components started to melt. While the engine is a long way off being flight ready, it goes to show just how hard it is to build even a bench-running turbojet. Even major world powers have struggled with this problem over the years. Video after the break.
Virtual reality is becoming more of a thing, now that we have high quality headsets and the computing power to generate attractive environments. Many VR systems use controllers held in mid air, or camera-based systems that track limbs and hands for interaction. However, productivity scenarios often require prolonged interactions over a long period of time, which typically necessitates working at surfaces that allow the body to rest intermittently. To help facilitate this, a group of researchers at ETH Zurich developed TapID, including a preprint paper (PDF) that will be presented at IEEE VR 2021 later this month.
TapID consists of a wristband that carries two motion sensors, with one worn on each wrist. This allows TapID to detect taps from each of the user’s fingers individually, thanks to a machine learning algorithm that analyses the unique vibrations through your skeletal system. This is demonstrated as being useful for VR environments, where the user can type into a virtual keyboard, or interact with virtual objects on a surface, using their fingers as they would in the real world. This is a sensor fusion with the features of modern VR headsets that include hand tracking. The TapID wristbands deliver granularity and detection of small motions that is not nearly as accurate through headset-mounted senors and camera-based detection.
Test hardware includes 4 accelerometers. Two on flexible PCBs are the sensing hardware used by the system, the other two on the rigid PCB are used as a baseline during testing but do not contribute to the tap detection.
We’re not entirely convinced of the utility of sitting down in a virtual environment to type at a fake keyboard when monitors and real keyboards are more tactile and cheaper. However, having a device that can accurately determine individual finger interactions is sure to have applications in VR. And whether or not the demonstrated use cases are viable, the technology does indeed work.
It’s exciting to see the wrist-band form factor. It brings to mind the possibility of improving tap interactions in smart watches for non-VR uses. We envision chorded keyboard type gestures that detect which fingers are tapping but don’t need positional accuracy.
Those experimenting in VR interfaces may find it useful to reverse engineer what’s already out on the market, as we’ve featured before. Or, you can simply build your own! Video after the break.
[Marco] has a sodium iodide detector that indicates cosmic radiation by scintillation. The material glows when hit by cosmic rays and, traditionally, a photomultiplier tube detects the photos from the detection. After a quick demonstration that you can see in the video below, he built the Cosmic Pi, a CERN project to create a giant distributed cosmic ray detector. The Cosmic Pi uses scintillation, but not from a crystal. It uses a plastic scintillator and silicon photodetectors, so it is much easier to work with than a traditional detector.
Using a four-layer board and some harvested components, the device detects muons. There are two scintillation detectors and muons striking both detectors presumably don’t have a local origin. The instrument has a GPS to get accurate time and position data. There are other sensors onboard, too, to collect data about the conditions of each detected event.
Again, let’s just get this out of the way up front: I got this lovely little 75% keyboard for free from a gaming accessories company called Marsback. It’s a functioning prototype of a keyboard that they have up on Kickstarter as of March 2nd. It comes in three color schemes: dark, white and sakura pink, which is white and pink with cherry blossoms.
This illustration of the lube points is from my email string with Marsback.
Marsback found me through my personal website and contacted me directly to gauge my interest in this keyboard. I’ll admit that I wasn’t too excited about it until I scrolled further in the email and saw that they are producing their own switches in-house.
I think that’s a really interesting choice given that Cherry MX and other switches exist, and there so many Cherry MX clones out there already. Naturally, I had to investigate, so following a short review, I’ll take it apart.
Historically, display technologies have always been power thirsty things. In the past, CRTs and incandescent bulbs sucked down electrons like they were free beer. Eventually, LEDs and LCDs came along and lowered this significantly, but the king of low power display technologies remains ePaper and eInk displays. Only requiring power when refreshing the display, they can be left off indefinitely, drawing little to no current. This is great for low-power builds such as [Andrew Lamchenko’s] miniature hygrometer. (Video, embedded below.)
The build runs on an nRF52811 microcontroller, hooked up to a 1.02″ ePaper display sourced for just $7. A SHT20 temperature and humidity sensor is then queried to sample the ambient conditions, and the results displayed on the screen. The benefit of this is that the device can be powered from a coin cell, and set to update at infrequent intervals – say, once per hour. It can then be checked by the user without having to turn on.
The low-power design means it would be the perfect device for leaving in a guitar case or humidor for months at a time. As a bonus, it’s also capable of Smart Home integration thanks to the Bluetooth capabilities onboard. It would likely be trivial to upgrade this into a tweeting humidor, the likes of which we haven’t seen since 2009!
