Here’s one for our astronomy geeks. Our hacker [arrow] has made their own observatory!

This particular video is a bit over ten minutes long and is basically a montage; there is no narration or explanation given, but you can watch clear progress being made and the ultimate success of the backyard facility.

Obviously the coolest thing about this building is that the roof can be moved, but those telescope mounts look pretty sexy too. About halfway through the video the concrete slab that was supporting one metal mounting pole gets torn up so that two replacements can be installed, thereby doubling the capacity of the observatory from one telescope to two.

If you’re an astronomy wonk you might enjoy some of [arrow]’s other videos. Maybe with their observatory [arrow] will solve the problem of dark matter. We’ve covered heaps of astronomy stuff here at Hackaday before including how to make your own telescope right down to the glass and the world’s highest altitude infrared telescope.

Thanks very much to [Joshua] for sending us this tip via the tips line.

Our hacker [Andrew Zonenberg] reports in on his open-source high-speed Ethernet switch. He hasn’t finished yet, but progress has been made.

If you were wondering what might be involved in a high-speed Ethernet switch implementation look no further. He’s been working on this project, on and off, since 2012. His design now includes a dizzying array of parts. [Andrew] managed to snag some XCKU5P FPGAs for cheap, paying two cents in the dollar, and having access to this fairly high-powered hardware affected the project’s direction.

You might be familiar with [Andrew Zonenberg] as we have heard from him before. He’s the guy who gave us the glscopeclient, which is now ngscopeclient.

As perhaps you know, when he says in his report that he is an “experienced RTL engineer”, he is talking about Register-Transfer Level, which is an abstraction layer used by hardware description languages, such as Verilog and VHDL, which are used to program FPGAs. When he says “RTL” he’s not talking about Resistor-Transistor Logic (an ancient method of developing digital hardware) or the equally ancient line of Realtek Ethernet controllers such as the RTL8139.

When it comes to open-source software you can usually get a copy at no cost. With open-source hardware, on the other hand, you might find yourself needing to fork out for some very expensive bits of kit. High speed is still expensive! And… proprietary, for now. If you’re looking to implement Ethernet hardware today, you will have to stick with something slower. Otherwise, stay tuned, and watch this space.

Here’s something fun. Our hacker [Willow Cunningham] has sent us a copy of his homework. This is his final project for the “ECE 574: Cluster Computing” course at the University of Maine, Orono.

It was enjoyable going through the process of having a good look at everything in this project. The project is a “cluster” of 5x Raspberry Pi Pico microcontrollers — with one head node as the leader and four compute nodes that work on tasks. The software for the both types of node is written in C. The head node is connected to a workstation via USB 1.1 allowing the system to be controlled with a Python script.

The cluster is configured to process an embarrassingly parallel image convolution. The input image is copied into the head node via USB which then divvies it up and distributes it to n compute nodes via I²C, one node at a time. Results are given for n = {1,2,4} compute nodes.

It turns out that the work of distributing the data dwarfs the compute by three orders of magnitude. The result is that the whole system gets slower the more nodes we add. But we’re not going to hold that against anyone. This was a fascinating investigation and we were impressed by [Willow]’s technical chops. This was a complicated project with diverse hardware and software challenges and he’s done a great job making it all work and in the best scientific tradition.

It was fun reading his journal in which he chronicled his progress and frustrations during the project. His final report in IEEE format was created using LaTeX and Overleaf, at only six pages it is an easy and interesting read.

For anyone interested in cluster tech be sure to check out the 256-core RISC-V megacluster and a RISC-V supercluster for very low cost.

Some hacks are so great that when you die you receive the rare honor of both an obituary in the New York Times and an in memoriam article at Hackaday.

The recently deceased, [Ed Smylie], was a NASA engineer leading the effort to save the crew of Apollo 13 with a makeshift gas conduit made from plastic bags and duct tape back in the year 1970. [Ed] died recently, on April 21, in Crossville, Tennessee, at the age of 95.

This particular hack, another in the long and storied history of duct tape, literally required putting a square peg in a round hole. After an explosion crippled the command module the astronauts needed to escape on the lunar excursion module. But the lunar module was only designed to support two people, not three.

The problem was that there was only enough lithium hydroxide onboard the lunar module to filter the air for two people. The astronauts could salvage lithium hydroxide canisters from the command module, but those canisters were square, whereas the canisters for the lunar module were round.

[Ed] and his team famously designed the required adapter from a small inventory of materials available on the space craft. This celebrated story has been told many times, including in the 1995 film, Apollo 13.

Thank you, [Ed], for one of the greatest hacks of all time. May you rest in peace.

Header: Gas conduit adapter designed by [Ed Smylie], NASA, Public domain.

The hack we have for you today is among our most favorite types of hack: a good, honest, simple, and well documented implementation that meets a real need. Our hacker [Solo Pilot] has sent in a link to their basement monitor.

The documentation is quite good. It’s terse but comprehensive with links to related information. It covers the background, requirements, hardware design, sensors, email and SMS alerts, software details, and even has some credits at the end.

Implementing this project would be a good activity for someone who has already made an LED flash and wants to take their skills to the next level by sourcing and assembling the hardware and then configuring, compiling, deploying, and testing the software for this real-world project.

To make this project work you will need to know your way around the Arduino IDE in order to build the software from the src.zip file included with the documentation (hint: extract the files from src.zip into a directory called AHT20_BMP280 before opening AHT20_BMP280.ino and make sure you add necessary boards and libraries).

One feature of the basement monitor that we would like to see is a periodic “everything’s okay” signal from the device, just so we can confirm that the reason we’re not getting an alarm about flooding in the basement is because there is no flood, and not because the battery ran dead or the WiFi went offline.

If you’ve recently started on your journey into where electronics meets software a project such as this one is a really great place to go next. And of course once you are proficient with the ESP8266 there are a thousand such projects here at Hackaday that you can cut your teeth on. Such as this clock and this fault injection device.

Recently in material science news from China we hear that [Hailin Peng] and his team at Peking University just made the world’s fastest transistor and it’s not made of silicon. Before we tell you about this transistor made from bismuth here’s a whirlwind tour of the history of the transistor.

The Bipolar Junction Transistor (BJT, such as NPN and PNP) was invented by Bell Labs in 1947. Later came Transistor-Transistor Logic (TTL) made with BJTs. The problem with TTL was too much power consumption.

Enter the energy-efficient Field-Effect Transistor (FET). The FET is better suited to processing information as it is voltage-controlled, unlike the BJT which is current-controlled. Advantages of FETs include high input impedance, low power consumption, fast switching speed, being well suited to Very-Large-Scale Integration (VLSI), etc.

The cornerstone of Complementary Metal-Oxide-Semiconductor (CMOS) technology which came to replace TTL was a type of FET known as the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). The type of MOSFET most commonly used in CMOS integrated circuits is the Enhancement-mode MOSFET which is normally off and needs gate voltage to conduct.

A transistor’s technology generation is given with the “process node”, in nanometers (nm). This used to mean the size of the smallest feature that could be fabricated, but these days it’s just a marketing term (smaller is “better”). Planar CMOS MOSFETs were initially dominant (through ~28nm), then came SOI MOSFETs (28nm to 16nm), then FinFETs (16nm to 5nm), and now finally Gate-All-Around FETs (GAAFETs, 3nm and beyond).

All of that in order to say that this new transistor from [Hailin Peng] and his team is a GAAFET. It’s made from bismuth oxyselenide (Bi₂O₂Se) for the channel, and bismuth selenite oxide (Bi₂SeO₅) as the gate material. See the article for further details.

Keep in mind that at this point in time we only have a prototype from a lab and the gory details about how to mass-produce these things, assuming that’s even possible, haven’t yet been worked out. We have previously discussed the difficulty of manufacturing state-of-the-art transistors. If you’re interested in bismuth be sure to check out how to use bismuth for desoldering.

Today in the it’s-surprising-that-it-works department we have a ding dong doorbell extension from [Ajoy Raman].

What [Ajoy] wanted to do was to extend the range of his existing doorbell so that he could hear it in his workshop. His plan of attack was to buy a new wireless doorbell and then interface its transmitter with his existing doorbell. But his approach is something others might not have considered if they had have been tasked with this job, and it’s surprising to learn that it works!

What he’s done is wrap a new coil around the ding dong doorbell’s solenoid. When the solenoid activates, a small voltage is induced into the coil. This then gets run into the wireless doorbell transmitter power supply (instead of its battery) via a rectifier diode and a filter capacitor. The wireless doorbell transmitter — having also had its push-button shorted out — operates for long enough from this induced electrical pulse to transmit the signal to the receiver. To be clear: the wireless transmitter is fully powered by the pulse from the coil around the solenoid. Brilliant! Nice hack!

We weren’t sure how reliable the transmitter would be when taken out of the lab and installed in the house so we checked in with [Ajoy] to find out. It’s in production now and operating well at a distance of around 50 feet!

Of course we’ve published heaps of doorbell hacks here on Hackaday before, such as this Bluetooth Low Energy (BLE) doorbell and this light-flashing doorbell. Have you hacked your own doorbell? Let us know on the tips line!

Today we are happy to present a web-based GUI for making a web-based GUI! If you’re a programmer then web front-end development might not be your bag. But a web-based graphical user interface (GUI) for administration and reporting for your microcontroller device can look very professional and be super useful. The Mongoose Wizard can help you develop a device dashboard for your ESP32-based project.

In this article (and associated video) the Mongoose developers run you through how to get started with their technology. They help you get your development environment set up, create your dashboard layout, add a dashboard page, add a device settings page, add an over-the-air (OTA) firmware update page, build and test the firmware, and attach the user-interface controls to the hardware. The generated firmware includes an embedded web server for serving your dashboard and delivering its REST interface, pretty handy.

You will find no end of ESP32-based projects here at Hackaday which you could potentially integrate with Mongoose. We think the OTA support is an excellent feature to have, but of course there are other ways of supporting that functionality.

Thanks to [Toly] for this tip.

Researchers from the USA and India have proposed that Floquet Majorana fermions may improve quantum computing by controlling superconducting currents, potentially reducing errors and increasing stability.

In a study published in Physical Review Letters that was co-authored by [Babak Seradjeh], a Professor of Physics at Indiana University Bloomington, and theoretical physicists [Rekha Kumari] and [Arijit Kundu], from the Indian Institute of Technology Kanpur, the scientists validate their theory using numerical simulations.

In the absence of room-temperature superconductors — the Holy Grail of superconductivity, everybody put your thinking caps on! — the low temperatures required lead to expense (for cooling) and errors (due to decoherence) which need to be managed. Using the techniques proposed by the study, quantum information may be modeled non-locally and be spread out spatially in a material, making it more stable and less error prone, immune to local noise and fluctuations.

Majorana fermions are named after Italian physicist [Ettore Majorana] who proposed them in 1937. Unlike most particles, Majorana fermions are their own antiparticles. In the year 2000 mathematical physicist [Alexei Kitaev] realized Majorana fermions can exist not only as elementary particles but also as quantum excitations in certain materials known as topological superconductors. Topological superconductors differ from regular superconductors in that they have unique, stable quantum states on their surface or edges that are protected by the material’s underlying topology.

Superconductivity is such an interesting phenomenon, where electrical resistance all but vanishes in certain materials when they are very cold. Usually to induce a current in a material you apply a voltage, or potential difference, in order to create the electrical pressure that results in the current. But in a superconductor currents can flow in the absence of an applied voltage. This is because of a peculiar quantum tunneling process known as the “Josephson effect”. It is hoped that by tuning the Josephson current using a superconductor’s “chemical potential” that we discover a new level of control over quantum materials.

Ettore Majorana picture: Mondadori Collection, Public domain.

A group of students from Lancing College in the UK have sent in their Critical Design Review (CDR) for their entry in the UK CanSat project.

Per the competition guidelines the UK CanSat project challenges students aged 14 to 19 years of age to build a satellite which can relay telemetry data about atmospheric conditions such as could help with space exploration. The students’ primary mission is to collect temperature and pressure readings, and these students picked their secondary mission to be collection of GPS data, for use on planets where GPS infrastructure is available, such as on Earth. This CDR follows their Preliminary Design Review (PDR).

The six students in the group bring a range of relevant skills. Their satellite transmits six metrics every second: temperature, pressure, altitude reading 1, altitude reading 2, latitude, and longitude. The main processor is an Arduino Nano Every, a BMP388 sensor provides the first three metrics, and a BE880 GPS module provides the following three metrics. The RFM69HCW module provides radio transmission and reception using LoRa.

The students present their plan and progress in a Gantt chart, catalog their inventory of relevant skills, assess risks, prepare mechanical and electrical designs, breadboard the satellite circuitry and receiver wiring, design a PCB in KiCad, and develop flow charts for the software. The use of Blender for data visualization was a nice hack, as was using ChatGPT to generate an example data file for testing purposes. Mechanical details such as parachute design and composition are worked out along with a shiny finish for high visibility. The students conduct various tests to ensure the suitability of their design and then conduct an outreach program to advertise their achievements to their school community and the internet at large.

We here at Hackaday would like to wish these talented students every success with their submission and we hope you had good luck on launch day, March 4th!

The backbone of this project is the LoRa technology and if you’re interested in that we’ve covered that here at Hackaday many times before, such as in this rain gauge and these soil moisture sensors.

In the Microchip tinyAVR 0-series, 1-series, and 2-series we see Configurable Custom Logic (CCL) among the Core Independent Peripherals (CIP) available on the chip. In this YouTube video [Grug Huhler] shows us how to make your own digital logic in hardware using the ATtiny CCL peripheral.

If you have spare pins on your tinyAVR micro you can use them with the CCL for “glue logic” and save on your bill of materials (BOM) cost. The CCL can do simple to moderately complex logic, and it does it without the need for support from the processor core, which is why it’s called a core independent peripheral. A good place to learn about the CCL capabilities in these tinyAVR series is Microchip Technical Brief TB3218: Getting Started with Configurable Custom Logic (CCL) or if you need more information see a datasheet, such as the ATtiny3226 datasheet mentioned in the video.

A tinyAVR micro will have one or two CCL peripherals depending on the series. The heart of the CCL hardware are two Lookup Tables (LUTs). Each LUT can map any three binary inputs into one binary output. This allows each LUT to be programmed with one byte as simple 2-input or 3-input logic, such as NOT, AND, OR, XOR, etc. Each LUT output can optionally be piped through a Filter/Sync function, an Edge Detector, and a Sequencer (always from the lower numbered LUT in the pair). It is also possible to mask-out LUT inputs.

In the source code that accompanies the video [Grug] includes a demonstration of a three input AND gate, an SR Latch using the sequencer, an SR Latch using feedback, and a filter/sync and edge detection circuit. The Arduino library [Grug] uses is Logic.h from megaTinyCore.

We have covered CIP and CCL technology here on Hackaday before, such as back when we showed you how to use an AVR microcontroller to make a switching regulator.

A recent project over on Hackaday.io from [Michael Gardi] is Trekulator – Where No Maker Has Gone Before.

This is a fun build and [Michael] has done a very good job of emulating the original device. [Michael] used the Hackaday.io logging feature to log his progress. Starting in September 2024 he modeled the case, got his original hardware working, got the 7-segment display working, added support for sound, got the keypad working and mounted it, added the TFT display and mounted it, wired up the breadboard implementation, designed and implemented the PCBs, added some finishing touches, installed improved keys, and added a power socket back in March.

It is perhaps funny that where the original device used four red LEDs, [Michael] has used an entire TFT display. This would have been pure decadence by the standards of 1977. The software for the ESP32 microcontroller was fairly involved. It had to support audio, graphics, animations, keyboard input, the 7-segment display, and the actual calculations.

The calculations are done using double-precision floating-point values and eight positions on the display so this code will do weird things in some edge cases. For instance if you ask it to sum two eight digit numbers as 90,000,000 and 80,000,000, which would ordinarily sum to the nine digit value 170,000,000, the display will show you a different value instead, such as maybe 17,000,000 or 70,000,000. Why don’t you put one together and let us know what it actually does! Also, can you find any floating-point precision bugs?

This was a really fun project, thanks to [Michael] for writing it up and letting us know via the tips line!

Forth is popular on small computers because it is simple to implement, yet quite powerful. But what happens when you really need to shrink it? Well, if your target is the 6502, there’s milliForth-6502.

This is a port of milliForth, which is a fork of sectorforth. The sectorforth project set the standard, implementing a Forth so small it could fit in a 512-byte boot sector. The milliForth project took sectorforth and made it even smaller, weighing in at only 336 bytes. However, both milliForth and sectorforth are for the x86 architecture. With milliForth-6502, [Alvaro G. S. Barcellos] wanted to see how small he could make a 6502 implementation.

So how big is the milliForth-6502 binary? Our tests indicate: 1,110 bytes. It won’t quite fit in a boot sector, but it’s pretty small!

Most of the code for milliForth-6502 is assembly code in sector-6502.s. This code is compiled using tools from the cc65 project. To run the code lib6502 is used for 6502 emulation.

Emulation is all well and good as far as it goes, especially for development and testing, but we’d love to see this code running on a real 6502. Even better would be a 6502 built from scratch! If you get this code running we’d love to hear how it went!

In this series of 23 YouTube videos [Rich] puts the AMD Zynq-7000 SoC through its paces by building a development board from the ground up to host it along with its peripherals. The Zynq is part FPGA and part CPU, and while it has been around for a while, we don’t see nearly as many projects about it as we’d like.

Rich covers everything from the power system to HDMI, USB, DDR RAM, and everything in between. By the end, he’s able to boot PetaLinux.

The Zynq SoC includes an ARM Cortex-A9 Based APU and an Artix-7 FPGA (or a Kintex-7 FPGA on higher models). In case you missed it, Xilinx was recently acquired by AMD, which is why you might have remembered this as a Xilinx part.

We’ve heard from [Rich] before. Back in 2021 we saw his Arduino Brings USB Mouse To Homebrew Computer. Don’t miss his follow-up playlist: Building on my Zynq-7000 in which he takes his Zynq-7000 board even further.

If you’re interested in FPGA technology but need something more easy going to get you started, be sure to check out how to build a 6809 CPU on an FPGA. Or, if you need something even simpler, report for boot camp.

Thanks to [Alex] for the tip!

It’s traditional to launch new software on April Fool’s Day, which is when we heard that Rockbox 4.0 has been released. But, in this case, the venerable MP3 firmware actually did update after a long absence. It’s great to see that good old Rockbox is still kicking along. We first mentioned Rockbox here at Hackaday approaching 20 years ago. How time flies. There used to be a whole ‘scene’ around hacking Personal Media Players (PMPs), also known as “MP3 Players”.

We tracked down Rockbox contributor [Solomon Peachy] to ask for some simple advice: If someone wants to install Rockbox on a personal media player today, what hardware should they buy? [Solomon] referred us to the AIGO EROS Q / EROS K, which is the only compatible hardware still being manufactured and sold. Beyond that, if you want to buy compatible hardware, you’ll need to find some secondhand somewhere, such as eBay. See the Rockbox Wiki for supported hardware.

Smartphones and streaming services have subsumed the single-purpose personal media player. Will you put the new Rockbox on something? Let us know in the comments.

What do you do with an unused nuclear reactor project? In Washington, one of them was hacked to remove sound, all in the name of science.

In 1977, a little way outside of Seattle, Washington Nuclear Projects 3 and 5 (WNP-3 and WNP-5) were started as part of Washington Public Power Supply System (WPPSS, pronounced “whoops”). They ran over budget, and in the 80s they were mothballed even though WNP-3 was nearly complete.

In 2010 when [Ron] and [Bonnie Sauro] were starting their new acoustical lab, NWAA Labs, they thought they wanted to build in a mountain, but what they found was an auxiliary reactor building. The structure was attached to a defunct nuclear power facility. With concrete and rebar walls five feet thick, it was the ideal site for their acoustical experiments and tests.

There are strict facility requirements from standards bodies such as American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) for acoustical labs which help ensure that different labs achieve comparable results. For example, you need stable temperature, humidity, and reverberation. The temperature within the facility is a stable 54 degrees Fahrenheit (12 degrees Celsius) regardless of the temperature outside.

Companies use acoustical labs to inform their designs and ensure that they meet acoustic standards or requirements, particularly those related to noise emissions. Over the last fifteen years, NWAA Labs has tested carpet samples, noise-cancelling headphones, sound-dampening construction materials, noisy washing machines, and even an airplane’s crew cabin!

If there was any question about whether [Ron Sauro] qualifies as a hacker, this quote removes all doubt: “I’m a carpenter, a plumber, a welder, I can fix a car,” he says. “Anything that needs to be done, I can do. Because I have to.”

Maybe we should send a wearable cone of silence to [Ron] for a complete test. If you’ve ever hacked a nuclear power plant, do let us know in the comments!

If your shop comes complete with a MIG welder, an acetylene torch, and an air hammer, then you have more options than most when it comes to removing broken bolts.

In this short video [Jim’s Automotive Machine Shop, Inc] takes us through the process of removing a broken manifold bolt: use a MIG welder to attach a washer, then attach a suitably sized nut and weld that onto the washer, heat the assembly with the acetylene torch, loosen up any corrosion on the threads by tapping with a hammer, then simply unscrew with your wrench! Everything is easy when you know how!

Of course if your shop doesn’t come complete with a MIG welder and acetylene torch you will have to get by with the old Easy Out screw extractor like the rest of us. And if you are faced with a nasty bolt situation keep in mind that lubrication can help.

This short video from [ProShorts 101] shows us how to build a variable speed disc sander from not much more than an old hard drive.

We feel that as far as hacks go this one ticks all the boxes. It is clever, useful, and minimal yet comprehensive; it even has a speed control! Certainly this hack uses something in a way other than it was intended to be used.

Take this ingenuity and add an old hard drive from your junkbox, sandpaper, some glue, some wire, a battery pack, a motor driver, a power socket and a potentiometer, drill a few holes, glue a few pieces, and voilà! A disc sander! Of course the coat of paint was simply icing on the cake.

The little brother of this hack was done by the same hacker on a smaller hard drive and without the speed control, so check that out too.

One thing that took our interest while watching these videos is what tool the hacker used to cut sandpaper. Here we witnessed the use of both wire cutters and a craft knife. Perhaps when you’re cutting sandpaper you just have to accept that the process will wear out the sharp edge on your tool, regardless of which tool you use. If you have a hot tip for the best tool for the job when it comes to cutting sandpaper please let us know in the comments! (Also, did anyone catch what type of glue was used?)

If you’re interested in a sander but need something with a smaller form factor check out how to make a sander from a toothbrush!