Day: March 9, 2025

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Hackaday Links: March 9, 2025

March 9, 2025 by 2 Comments

It’s been a busy week in space news, and very little of it was good. We’ll start with the one winner of the week, Firefly’s Blue Ghost Mission 1, which landed successfully on the Moon’s surface on March 2. The lander is part of NASA’s Commercial Lunar Payload Services program and carries ten scientific payloads, including a GPS/GNSS receiver that successfully tracked signals from Earth-orbiting satellites. All of the scientific payloads have completed their missions, which is good because the lander isn’t designed to withstand the long, cold lunar night only a few days away. The landing makes Firefly the first commercial outfit to successfully soft-land something on the Moon, and being the first at anything is always a big deal.

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Deep Drawing With Ultrasonics

March 9, 2025 by 12 Comments

Small cylindrical parts are often formed through deep drawing — a process by which a punch forms the finished piece from a flat sheet of metal using a forming die. If it sounds like that stresses the metal, it does. But researchers at Fraunhofer have found a way to reduce friction protecting both the material and the tools that do the forming. The process — known as VibroDraw — uses ultrasonic vibrations at around 500 Hz.

Researchers claim a 20% reduction in friction now, and it may be possible to go even further. With less friction, it is possible to do a deeper draw in a single stage. It also creates less heat which is good for tool life and prevents overheating lubricant. The process has a patent if you want more details. You might need to brush up on your German, though. Unsurprisingly, the vibrations are from a piezoelectric transducer.

Copper is soft enough to use 3D printed dies. We don’t know if this technique would help with that or not. Then there’s hydroforming. If you have any results using ultrasonics with these or any other techniques, be sure to let us know.

Old Chromebooks Get Second Life As Video Wall

March 9, 2025 by 12 Comments

What would you do with dozens and dozens of outdated Chromebooks that are no longer getting updates from the Google Mothership? It’s a situation that plenty of schools will have to deal with in the near future, and we can only help that those institutions have students as clever as [Varun Biniwale] and his friend [Aksel Salmi] to lean on — as they managed to recycle ten of these outdated laptops into an impressive video display.

There’s actually two write-ups for this particular story, with [Varun] documenting the modification of the Chromebooks and the software developed to play the video between them, and [Aksel] covering how the hardware was ultimately attached to the wall via bespoke 3D printed mounting brackets.

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self-stabilizing robot on tabletop

Taming The Wobble: An Arduino Self-Balancing Bot

March 9, 2025 by 7 Comments

Getting a robot to stand on two wheels without tipping over involves a challenging dance with the laws of physics. Self-balancing robots are a great way to get into control systems, sensor fusion, and embedded programming. This build by [mircemk] shows how to make one with just a few common components, an Arduino, and a bit of patience fine-tuning the PID controller.

At the heart of the bot is the MPU6050 – a combo accelerometer/gyroscope sensor that keeps track of tilt and movement. An Arduino Uno takes this data, runs it through a PID loop, and commands an L298N motor driver to adjust the speed and direction of two DC motors. The power comes from two Li-ion batteries feeding everything with enough juice to keep it upright. The rest of the magic lies in the tuning.

PID (Proportional-Integral-Derivative) control is what makes the robot stay balanced. Kp (proportional gain) determines how aggressively the motors respond to tilting. Kd (derivative gain) dampens oscillations, and Ki (integral gain) helps correct slow drifts. Set them wrong, and your bot either wobbles like a confused penguin or falls flat on its face. A good trick is to start with only Kp, then slowly add Kd and Ki until it stabilizes. Then don’t forget to calibrate your MPU6050; each sensor has unique offsets that need to be compensated in the code.

Once dialed in, the result is a robot that looks like it defies gravity. Whether you’re hacking it for fun, turning it into a segway-like ride, or using it as a learning tool, a balancing bot is a great way to sharpen your control system skills. For more inspiration, check out this earlier attempt from 2022, or these self-balancing robots (one with a little work) from a year before that. You can read up on [mircemk]’s project details here.

Fixing An Unpleasant SD Card Slot Issue In A NanoVNA

March 9, 2025 by 7 Comments

SD cards & the much smaller microSD cards are found on many devices, with the card often accessible from outside the enclosure. Unfortunately there’s a solid chance that especially small microSD cards will find their way past the microSD card reader slot and into the enclosure. This is what happened to [Rob] of the SevenFortyOne Radios and Repairs channel on YouTube with a NanoVNA unit. While shaking the unit, you can clearly hear the microSD card rattling inside, courtesy of the rather large gap above the card slot.

After a quick teardown and extracting the lost microSD card, the solution to prevent this is a simple bit of foam stuck on top of the microSD card slot, so that the too large opening in the enclosure is now fully blocked. It’s clearly a bit of a design fail in this particular NanoVNA unit, worsened by the tiny size of the card and having to use a fingernail to push the card into the slot as it’s so far inside the enclosure.

While [Rob] seems to blame himself for this event, we’d chalk it mostly up to poor design. It’s an issue that’s seen with certain SBC enclosures and various gadgets too, where losing a microSD card is pretty much a matter of time, and hugely fiddly at the best of times. That said, what is your preferred way of handling microSD card insertion & removal in devices like these?

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ice forming on surface with plus and minus pole

The Coolest Batteries You’ve Never Heard Of

March 9, 2025 by 33 Comments

Imagine cooling your building with the same principle that kept Victorian-era icehouses stocked with lake-frozen blocks, but in modern form. That’s the idea behind ice batteries, a clever energy storage hack that’s been quietly slashing cooling costs across commercial buildings. The invention works by freezing water when energy is cheap, and using that stored cold later, they turn major power hogs (air conditioning, we’re looking at you) into more efficient, cost-effective systems.

Pioneers like Nostromo Energy and Ice Energy are refining the tech. Nostromo’s IceBrick modules pack 25 kWh of cooling capacity each, install on rooftops, and cost around $250 per kWh—about half the price of lithium-ion storage. Ice Energy’s Ice Bear 40 integrates with HVAC systems, shifting up to 95% of peak cooling demand to off-peak hours. And for homes, the Ice Bear 20 replaces traditional AC units while doubling as a thermal battery.

Unlike lithium-ion, ice batteries don’t degrade chemically – their water is endlessly reusable. Combining the technology with this hack, it’s even possible in environments where water is scarce. But the trade-off? They only store cooling energy. No frozen kilowatts for your lightbulbs, just an efficient way to handle the biggest energy drain in most buildings.

Could ice batteries help decentralize energy storage? They’re already proving their worth in high-demand areas like California and Texas. Read the full report here and let us know your thoughts in the comments.

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