Comprehensive Power Management For The Raspberry Pi

January 30, 2026 by No comments

The Raspberry Pi has been a revolutionary computer in the maker space, providing a full Linux environment, GUI, and tons of GPIO and other interfacing protocols at a considerably low price. This wasn’t its original intended goal, though. Back in the early 2010s it was supposed to be an educational tool for students first, not necessarily a go-to for every electronics project imaginable. As such there are a few issues with the platform when being used this way, and [Vin] addresses his problems with its power management in his latest project.

[Vin]’s main issue is that, unlike a microcontroller, the Raspberry Pi doesn’t have a deep sleep function. That means that even when the operating system is shut down the computer is still drawing an appreciable amount of current, which will quickly drain some batteries. We’ve covered [Vin]’s farm and his use case for the Raspberry Pi in the past, but a quick summary is that these boards are being used in a very rugged environment where utility power isn’t as reliable as he would like.

In [Vin]’s post he not only outlines his design for the board but goes through his design process, starting by using discrete logic components and then trying out various microcontrollers until settling on an ATmega88. The microcontroller communicates with the Raspberry Pi over I2C where the Pi can request a power-down as well as a time for future power-on. A latching relay controlled by the microcontroller ensures the Pi doesn’t drain any battery while the ATmega can put itself into actual sleep in the meantime.

The build for this project goes into an impressive amount of detail, and not only are the designs and code available on the project’s GitHub page but [Vin] also wrote another blog post which uses this project to go over his design philosophy more broadly.

Companion MIDI Pedal Helps Roland Groovebox Along

January 30, 2026 by 1 Comment

The Roland SP-404 Mk2 is a popular groovebox that can deliver a great beat if you know how to use it. If you’re seeking greater control than is available out of the box, though, you might like to try a custom pedal built by [Romain Dereu].

The concept is simple enough—[Romain] whipped up a bespoke MIDI device to specifically control various features of the SP-404. It’s based on an Arduino Nano, though it could also be built with an Arduino Uno if so desired. The microcontroller sends the requisite MIDI messages out via its serial UART. The microcontroller is built into a pedal-style enclosure with a big toggle switch and a foot switch. This enables the triggering of various pads on the SP-404, with modes selected via the toggle.

It’s a simple build that opens up new possibilities when playing with the SP-404. If you’ve ever wanted a custom device to spit out some specific MIDI commands to control the synths or drum machines in your performance rig, this project is a great example of how easy this is to achieve. Meanwhile, if you’re whipping your own custom MIDI gear at home, we always love to see it land on our tipsline!

Lazarustorm Lets A PiStorm Live Outside Your Old Amiga

January 29, 2026 by No comments

The PiStorm is nothing new; if you’re familiar with the retrocomputer scene, you’ve probably heard of it. By replacing the 68k processor in an old Amiga (or some models of Atari) the PiStorm accelerator gives a multiple order of magnitude speedup. It’s even a reversable mod, plugging in where the original CPU was. What’s not to love? Well, some people would simply prefer to keep their original CPUs in place. [TME Retro] has a video highlighting the solution for those people: the Lazarustorm by [arananet].

It makes perfect sense to us– back in the day, you could plug a whole x86 PC-compatible ‘sidecar’ into your Amiga, so why not a PiStorm? The whole bus is right there for the taking.The Lazarusstorm, as a project, is bog simple compared to the PiStorm itself. A PCB and the connectors to get it plugged into the expansion port on the Amiga side, and the connectors to plug the PiStorm into it on the other. A couple of jumpers and a few passives, and that’s it. [TME Retro] also took the time to come up with a case for it, which sits on felt feet to relieve stress on the PCBs. It’s a nice bit of CAD, but we rather wish he’d done it in beige.

As for the upgraded Amiga, it runs just as fast as it would had the 68k been replaced with a Pi3 and PiStorm internally, which is to say it’s practically a supercomputer by 1980s standards. You get the SD card to serve as a hard drive and can even access the internet via modern WiFi, something Commodore engineers likely never expected an A500 to do. Of course, just connecting to the network is only half the battle when getting these retro machines online. When these accelerators were new, the 68k emulation ran on top of Linux, but now that the EMU68k project has it bare metal and even faster.

This isn’t the first Raspberry-flavoured slice of Amiga sidecar we’ve featured: here’s one running Spotify. If you haven’t got an Amiga, there’s a PiStorm for the FPGA-based MiniMig, too. Continue reading “Lazarustorm Lets A PiStorm Live Outside Your Old Amiga” →

Rare-Earth-Free Magnets With High Entropy Borides

January 29, 2026 by 5 Comments
Map of the calculated magnetic anisotropy. (Credit: Beeson et al., Adv. Mat., 2025)
Map of the calculated magnetic anisotropy. (Credit: Beeson et al., Adv. Mat., 2025)

Although most of us simultaneously accept the premise that magnets are quite literally everywhere and that few people know how they work, a major problem with magnets today is that they tend to rely on so-called rare-earth elements. Although firmly in the top 5 of misnomers, these abundant elements are hard to mine and isolate, which means that finding alternatives to their use is much desired. Fortunately the field of high entropy alloys (HEAs) offers hope here, with [Beeson] and colleagues recently demonstrating a rare-earth-free material that could be used for magnets.

Although many materials can be magnetic, to make a good magnet you need the material in question to be both magnetically anisotropic and posses a clear easy axis. This basically means a material that has strong preferential magnetic directions, with the easy axis being the orientation which is the most energetically favorable.

Through experimental validation with magnetic coercion it was determined that of the tested boride films, the (FeCoNiMn)2B variant with a specific deposition order showed the strongest anisotropy. What is interesting in this study is how much the way that the elements are added and in which way determines the final properties of the boride, which is one of the reasons why HEAs are such a hot topic of research currently.

Of course, this is just an early proof-of-concept, but it shows the promise of HEAs when it comes to replacing other types of anisotropic materials, in particular where – as noted in the paper – normally rare-earths are added to gain the properties that these researchers achieved without these elements being required.

Solar Supercapacitor Lamp Probably Won’t Get You Saved At Sea

January 29, 2026 by 9 Comments

Most solar lights are cheap garbage that exist just to put more microplastics into the environment as they degrade in short order. [Jeremy Cook] built his own solar light, however, and this one might just last a little longer.

Most solar lights rely on the cheapest nickel-cadmium or nickel-metal hydride cells that are available on the market. They don’t tend to have a lot of capacity and they wear out incredibly fast. [Jeremy] went a different route for his build, though, instead relying on a rather tasty supercapacitor to store energy. Unlike a rechargeable battery, that may only last a few thousand cycles, these supercaps are expected to perform over 500,000 charge/discharge cycles without failure. With such longevity, [Jeremy] suggests his build could last a full 1369.8 years, assuming it charged and discharged once a day. Whether the plastic transistor, LEDs, or diode could hold up over such a long period is another question entirely.

Electronically, the build is relatively simple. The solar panel collects light energy and turns it into electricity, charging the supercaps through a diode. The supercaps are only able to discharge through a transistor, which only turns on when the voltage output by the solar panel drops at night time, and the voltage on the base becomes lower than that on the emitter. When current flows through the transistor, it then lights the LED in turn and the device glows in the darkness. As a nice touch, the whole circuit is installed in a glass jug of syrup originally sourced from Costco. Files are on Github for those eager to explore further.

Given the light-in-a-bottle construction, [Jeremy] also playfully imagined that a lamp like this could theoretically be used as a safety device. If lost at sea, you could charge it using the sun and try and use it to signal for help. However, upon casually exploring the concept, he notes that a small solar-powered light will only raise the chance of a far-off ocean rescue from “extremely unlikely” to “still very unlikely.”

You can do all kinds of neat things with free energy from the sun, from mowing your lawn to processing waste products. Video after the break.

Continue reading “Solar Supercapacitor Lamp Probably Won’t Get You Saved At Sea” →

Handheld Steering Wheel Controller Gets Force-Feedback

January 29, 2026 by 3 Comments

For a full-fledged, bells-and-whistles driving simulator a number of unique human interface devices are needed, from pedals and shifters to the steering wheel. These steering wheels often have force feedback, with a small motor inside that can provide resistance to a user’s input that feels the same way that a steering wheel on a real car would. Inexpensive or small joysticks often omit this feature, but [Jason] has figured out a way to bring this to even the smallest game controllers.

The mechanism at the center of his controller is a DC motor out of an inkjet printer. Inkjet printers have a lot of these motors paired with rotary encoders for precision control, which is exactly what is needed here. A rotary encoder can determine the precise position of the controller’s wheel, and the motor can provide an appropriate resistive force depending on what is going on in the game. The motors out of a printer aren’t plug-and-play, though. They also need an H-bridge so they can get driven in either direction, and the entire mechanism is connected to an Arduino in the base of the controller to easily communicate with a computer over USB.

In testing the controller does behave like its larger, more expensive cousins, providing feedback to the driver and showing that it’s ready for one’s racing game of choice. It’s an excellent project for those who are space-constrained or who like to game on the go, but if you have more space available you might also want to check out [Jason]’s larger version built from a power drill instead parts from an inkjet.

Continue reading “Handheld Steering Wheel Controller Gets Force-Feedback” →

The Inner Workings Of The Intel 8086’s Arithmetic Logic Unit

January 29, 2026 by 5 Comments

In the 1970s CPUs still had wildly different approaches to basic features, with the Intel 8086 being one of them. Whereas the 6502 used separate circuits for operations, and the Intel 8085 a clump of reconfigurable gates, the 8086 uses microcode that configures the ALU along with two lookup tables. This complexity is one of the reasons why the Intel 8086 is so unique, with [Ken Shirriff] taking an in-depth look at its workings on a functional and die-level.

These lookup tables are used for the ALU configuration – as in the above schematic – making for a very flexible but also complex system, where the same microcode can be used by multiple instructions. This is effectively the very definition of a CISC-style processor, a legacy that the x86 ISA would carry with it even if the x86 CPUs today are internally more RISC-like. Decoding a single instruction and having it cascade into any of a variety of microcodes and control signals is very powerful, but comes with many trade-offs.

Of course, as semiconductor technology improved, along with design technologies, many of these trade-offs and disadvantages became less relevant. [Ken] also raises the interesting point that much of this ALU control technology is similar to that used in modern-day FPGAs, with their own reconfigurable logic using LUTs that allow for on-the-fly reconfiguration.