Day: July 27, 2025

Experience Other Planets With The Gravity Simulator

July 27, 2025 by 8 Comments

As Earthlings, most of us don’t spend a lot of extra time thinking about the gravity on our home planet. Instead, we go about our days only occasionally dropping things or tripping over furniture but largely attending to other matters of more consequence. When humans visit other worlds, though, there’s a lot more consideration of the gravity and its effects on how humans live and many different ways of training for going to places like the Moon or Mars. This gravity simulator, for example, lets anyone experience what it would be like to balance an object anywhere with different gravity from Earth’s.

The simulator itself largely consists of a row of about 60 NeoPixels, spread out in a line along a length of lightweight PVC pipe. They’re controlled by an Arduino Nano which has a built-in inertial measurement unit, allowing it to sense the angle the pipe is being held at as well as making determinations about its movement. A set of LEDs on the NeoPixel strip is illuminated, which simulates a ball being balanced on this pipe, and motion one way or the other will allow the ball to travel back and forth along its length. With the Earth gravity setting this is fairly intuitive but when the gravity simulation is turned up for heavier planets or turned down for lighter ones the experience changes dramatically. Most of the video explains the math behind determining the effects of a rolling ball in each of these environments, which is worth taking a look at on its own.

While the device obviously can’t change the mass or the force of gravity by pressing a button, it’s a unique way to experience and feel what a small part of existence on another world might be like. With enough budget available there are certainly other ways of providing training for other amounts of gravity like parabolic flights or buoyancy tanks, although one of the other more affordable ways of doing this for laypeople is this low-gravity acrobatic device.

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The Power-Free Tag Emulator

July 27, 2025 by 12 Comments

Most of you know how an NFC tag works. The reader creates an RF field that has enough energy to power the electronics in the tag; when the tag wakes up, two-way communication ensues. We’re accustomed to blank tags that can be reprogrammed, and devices like the Flipper Zero that can emulate a tag. In between those two is [MCUer]’s power-free tag emulator, a board which uses NFC receiver hardware to power a small microcontroller that can run emulation code.

The microcontroller in question is the low-power CW32L010 from Wuhan Xinyuan Semiconductor, a Chinese part with an ARM Cortex M0+ on board. Unfortunately, that’s where the interesting news ends, because all we can glean from the GitHub repository is a PCB layout. Not even a circuit diagram, which we hope is an unintended omission rather than deliberate. It does, however, lend itself to the fostering of ideas, because if this designer can’t furnish a schematic, then perhaps you can. It’s not difficult to make an NFC receiver, so perhaps you can hook one up to a microcontroller and be the one who shares the circuit.

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Hackaday Links: July 27, 2025

July 27, 2025 by 9 Comments

Sad breaking news late this Sunday afternoon of the passing of nerd icon Tom Lehrer at 97. Coming up through the culture, knowing at least a few of Tom’s ditties, preferably “The Elements” or “Poisoning Pigeons in the Park,” was as essential to proving one’s bona fides as committing most Monty Python bits to memory. Tom had a way with words that belied his background as a mathematician, spicing his sarcastic lyrics with unusual rhymes and topical references that captured the turbulence of the late 50s and early 60s, which is when he wrote most of his well-known stuff. First Ozzy, then Chuck Mangione, now Tom Lehrer — it’s been a rough week for musicians.

Here we go again. It looks like hams have another spectrum grab on their hands, but this time it’s the popular 70-cm band that’s in the crosshairs. Starlink wannabe AST SpaceMobile, which seeks to build a constellation of 248 ridiculously large communication satellites to offer direct-to-device service across the globe, seeks a substantial chunk of the 70-cm band, from 430 to 440 MHz, to control the satellites. This is smack in the middle of the 70-cm amateur radio band allocation here in the US, but covers the entire band for unlucky hams in Europe and the UK. The band is frequently used for repeaters, which newbie hams can easily access using a cheap hand-held radio to start learning the ropes.

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RPI TinynumberHat9

2025 One Hertz Challenge: RPI TinynumberHat9

July 27, 2025 by 2 Comments

This eye-catching entry to the One Hertz Challenge pairs vintage LED indicators with a modern RPi board to create a one-of-a-kind clock. The RPI TinynumberHat9 by [Andrew] brings back the beautiful interface from high end electronics of the past.

This project is centered around the red AL304 and green ALS314V 7-segment display chips. These 7-segment displays were produced in the 1970s and 1980s in the Soviet Union; you can still find them, but you’ll have to do some digging as they are only becoming more rare. [Andrew] included the data sheet for these which was a good find, it is written in Russian but doesn’t hold any surprises, these tiny LEDs typically forward current is 5mA at 2V. One of the things that jumps out about these LEDs is the gold leads, a sure sign of being a high-end component of their day.

When selecting a driving chip for the LEDs, [Andrew] looked at the MAX7219 and HT16K33; he settled on the HT16K33 as it supports I2C as well as allows the easy addition of buttons to the HAT. Due to being driven by I2C, he was also able to add a Qwiic/Stemma I2C connector, so while designed initially to be a HAT for a Raspberry Pi Zero 2 W board, it can be connected to other things in the Qwiic/Stemma ecosystem.

Thanks [Andrew] for submitting this beautiful entry into the One Hertz Challenge. We love unique 7-segment displays, and so it’s pretty awesome to see 40-year-old display tech brought into the present.

2025 Hackaday One Hertz Challenge

 

A Very Tidy Handheld Pi Terminal Indeed

July 27, 2025 by 25 Comments

As single board computers have become ever smaller and more powerful, so have those experimenting with them tried to push the boundaries of the machines they can be used in. First we had cyberdecks, and now we have handheld terminals. Of this latter class we have a particularly nice example from [Random Alley Cat]. It takes a Raspberry Pi Zero 2W and a handful of other parts, and makes them with a 3D printed case into something very professional indeed.

One of the problems with these designs has always been tidily packing away all the parts with their cables, and it’s one she solves by making a chassis to hold all the parts, and a case which fits around that. In a stroke the case no longer has to provide a dual function, allowing for a much easier internal layout. Her screen is a Pimoroni Hyperpixel, the keyboard is an Xbox 360 accessory, and the power supply is an off the shelf Pi UPS board and battery.

We particularly like the accesses on the underside of this machine to access the Pi ports, and the ventilation holes and external case details. It’s not perfect, as she says in the video below it’s not the best Linux keyboard. but we could really see ourselves using this.

If you follow handheld cyberdecks, we have a few treats for you on these pages. Not all of them run Linux, for example.

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Game Boy Camera In Wedding Photo Booth

July 27, 2025 by 12 Comments

For those of a certain age the first digital camera many of us experienced was the Game Boy Camera, an add-on for the original Game Boy console. Although it only took pictures with the limited 4-tone monochrome graphics of this system, its capability of being able to take a picture, edit it, create drawings, and then print them out on the Game Boy Printer was revolutionary for the time. Of course the people who grew up with this hardware are about the age to be getting married now (or well beyond), so [Sebastian] capitalized on the nostalgia for it with this wedding photo booth that takes pictures with the Game Boy Camera.

The photo booth features the eponymous Game Boy Camera front-and-center, with a pair of large buttons to allow the wedding guests to start the photography process. The system takes video and then isolates a few still images from it to be printed with the Game Boy Printer. The original Game Boy hardware, as well as a Flask-based web app with a GUI, is all controlled with a Raspberry Pi 4. There’s also a piece of Game Boy hardware called the GB Interceptor that sits between the Game Boy console and the camera cartridge itself which allows the Pi to capture the video feed directly.

The booth doesn’t stop with Game Boy hardware, though. There’s also a modern mirrorless digital camera set up in the booth alongside the Game Boy Camera which allows for higher resolution, full color images to be taken as well. This is also controlled with the same hardware and provides a more modern photo booth experience next to the nostalgic one provided by the Game Boy. There have been many projects which attempt to modernize this hardware, though, like this build which adds color to the original monochrome photos or this one which adds Wi-Fi capability.

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A Cable Modem, The Way All Network Gear Should Be Mounted

July 27, 2025 by 25 Comments

Home routers and cable modems are now extremely powerful devices, but they all suffer from the attention of their manufacturers’ design and marketing departments. Instead of neatly packaging them in functional cases, they impose aesthetics and corporate identity on them, usually resulting in a curvy plastic case that’s difficult to integrate with other network infrastructure. [The Eccentric Workshop] did something about this with their new Arris modem, by creating a new 19″ rack mount for it.

Unusually for such a device, the plastic case was easy to dismantle. There’s a PCB inside, and a light guide for its LEDs. A new lower-half case and light guide were designed and 3D printed, and the whole was then mounted in a 1U rack case. The special part of this hack perhaps lies in the front panel, a very professionally cut and laser etched affair complete with an Arris logo as though it were meant to be this way.

We also like having our infrastructure and other things in a rack here at Hackaday, and fondly remember the days when some surprisingly affordable boxes came with metal wings for rack mounting. It’s always possible to use a rack tray, but something like this is so much more attractive.