The Texas Instruments branding with some schematic symbols in background.

More Than 100 Sub-Circuit Designs From Texas Instruments

October 15, 2025 by 15 Comments

We were recently tipped off to quite a resource — on the Texas Instruments website, there’s a page where you can view and download a compendium of analog sub-circuits.

Individual circuits can be downloaded in the form of PDF files. If you chose to register (which is free), you’ll also gain access to the pair of e-books listed at the bottom of the page: Analog Engineer’s Circuit Cookbook: Amplifiers and Analog Engineer’s Circuit Cookbook: Data Converters. The data converter circuits can be further subdivided into analog-to-digital converter (ADC) circuits and digital-to-analog converter (DAC) circuits.

There are more than 60 amplifier circuits including basic circuits, current sensing circuits, signal sources, current sources, filters, non-linear circuits (rectifiers/clamps/peak detectors), signal conditioning, comparators, sensor acquisition, audio, and integrated amplifier circuits using MSP430 microcontrollers.

You’ll also find 39 analog-to-digital converter (ADC) circuits including low-power, small size, and cost optimized circuits; level translation and input drive circuits; low-level sensor input circuits; input protection, filtering and isolation circuits; and commonly used auxiliary circuits. Finally, there are 15 digital-to-analog converter (DAC) circuits including audio outputs, auxiliary and biasing circuits, current sources, and voltage sources.

Thanks to [Lee Leduc] for letting us know over on the EEVblog Forum.

Factorio Running On Mobile

October 15, 2025 by 23 Comments

As a video game, DOOM has achieved cult status not just for its legendary gameplay and milestone developments but also because it’s the piece of software that’s likely been ported to the most number of platforms. Almost everything with a processor can run the 1993 shooter, but as it ages, this becomes less of a challenge. More modern games are starting to move into this position, and Factorio may be taking a leading position. [Point Substantial] has gotten this game to run on a mobile phone.

The minimum system requirements for Factorio are enough to make this a challenge, especially compared to vintage title like DOOM. For Linux systems a dual-core processor and 8 GB of memory are needed, as well as something with at least 1 GB of VRAM. [Point_Substantial]’s Xiaomi Mi 9T almost meets these official minimum requirements, with the notable exception of RAM. This problem was solved by adding 6 GB of swap space to make up for the difference.

The real key to getting this running is that this phone doesn’t run Android, it runs the Linux-only postmarketOS. Since it’s a full-fledged Linux distribution rather than Android, it can run any software any other Linux computer can, including Steam. And it can also easily handle inputs for periphreals including a Switch Pro controller, which is important because this game doesn’t have touch inputs programmed natively.

The other tool that [Point_Substantial] needed was box86/box64, a translation layer to run x86 code on ARM. But with all the pieces in place it’s quite possible to run plenty of games semi-natively on a system like this. In fact, we’d argue it’s a shame that more phones don’t have support for Linux distributions like postmarketOS based on the latest news about Android.

Thanks to [Keith] for the tip!

A Record Lathe For Analog Audio Perfection

October 14, 2025 by 9 Comments

It’s no secret that here at Hackaday we’ve at times been tempted to poke fun at the world of audiophiles, a place where engineering sometimes takes second place to outright silliness. But when a high quality audio project comes along that brings some serious engineering to the table we’re all there for it, so when we saw [Slyka] had published the files for their open source record lathe, we knew it had to be time to bring it to you.

Truth be told we’ve been following this project for quite a while as they present tantalizing glimpses of it on social media, so while as they observe, documentation is hard, it should still be enough for anyone willing to try cutting their own recordings to get started. There’s the lathe itself, the controller, the software, and a tool for mapping EQ curves. It cuts in polycarbonate, though sadly there doesn’t seem to be a sound sample online for us to judge.

If you’re hungry for more this certainly isn’t the first record lathe we’ve brought you, and meanwhile we’ve gone a little deeper into the mystique surrounding vinyl.

Continue reading “A Record Lathe For Analog Audio Perfection” →

C Project Turns Into Full-Fledged OS

October 14, 2025 by 6 Comments

While some of us may have learned C in order to interact with embedded electronics or deep with computing hardware of some sort, others learn C for the challenge alone. Compared to newer languages like Python there’s a lot that C leaves up to the programmer that can be incredibly daunting. At the beginning of the year [Ethan] set out with a goal of learning C for its own sake and ended up with a working operating system from scratch programmed in not only C but Assembly as well.

[Ethan] calls his project Moderate Overdose of System Eccentricity, or MooseOS. Original programming and testing was done in QEMU on a Mac where he was able to build all of the core components of the operating system one-by-one including a kernel, a basic filesystem, and drivers for PS/2 peripherals as well as 320×200 VGA video. It also includes a dock-based GUI with design cues from operating systems like Macintosh System 1. From that GUI users can launch a few applications, from a text editor, a file explorer, or a terminal. There’s plenty of additional information about this OS on his GitHub page as well as a separate blog post.

The project didn’t stay confined to the QEMU virtual machine either. A friend of his was throwing away a 2009-era desktop which [Ethan] quickly grabbed to test his operating system on bare metal. There was just one fault that the real hardware threw that QEMU never did, but with a bit of troubleshooting it was able to run. He also notes that this was inspired by a wiki called OSDev which, although a bit dated now, is a great place to go to learn about the fundamentals of operating systems. We’d also recommend checking out this project that performs a similar task but on the RISC-V instruction set instead.

A photo of the old mechanical and new digital altimeters

Ben Eater Explains How Aircraft Systems Communicate With The ARINC 429 Protocol

October 14, 2025 by 3 Comments

Over on his YouTube channel the inimitable [Ben Eater] takes a look at an electronic altimeter which replaces an old mechanical altimeter in an airplane.

The old altimeter was entirely mechanical, except for a pair of wires which can power a backlight. Both the old and new altimeters have a dial on the front for calibrating the meter. The electronic altimeter has a connector on the back for integrating with the rest of the airplane. [Ben] notes that this particular electronic altimeter is only a backup in the airplane it is installed in, it’s there for a “second opinion” or in case of emergency.

Continue reading “Ben Eater Explains How Aircraft Systems Communicate With The ARINC 429 Protocol” →

Standalone CNC Tube Cutter/Notcher Does It With Plasma

October 14, 2025 by 9 Comments

Tubes! Not only is the internet a series of them, many projects in the physical world are, too. If you’re building anything from a bicycle to a race cart to and aeroplane, you might find yourself notching and welding metal tubes together. That notching part can be a real time-suck. [Jornt] from HOMEMADE MADNESS (it’s so mad you have to shout the channel name, apparently) thought so when he came up with this 3-axis CNC tube notcher.

If you haven’t worked with chrome-molly or other metal tubing, you may be forgiven for wondering what the big deal is, but it’s pretty simple: to get a solid weld, you need the tubes to meet. Round tubes don’t really want to do that, as a general rule. Imagine the simple case of a T-junction: the base of the T will only meet the crosspiece in a couple of discreet points. To get a solid joint, you have to cut the profile of the crosspiece from the end of the base. Easy enough for a single T, but for all the joins in all the angles of a space-frame? Yeah, some technological assistance would not go amiss.

Which is where [Jornt]’s project comes in. A cheap plasma cutter sits on one axis, to cut the tubes as they move under it. The second axis spins the tube, which is firmly gripped by urethane casters with a neat cam arrangement. The third axis slides the tube back and forth, allowing arbitarily long frame members to be cut, despite the very compact build of the actual machine. It also allows multiple frame members to be cut from a single long length of tubing, reducing setup time and speeding up the overall workflow. Continue reading “Standalone CNC Tube Cutter/Notcher Does It With Plasma” →

2025 Component Abuse Challenge: Making A TTL Demultiplexer Sweat

October 14, 2025 by 6 Comments

When we think of a motor controller it’s usual to imagine power electronics, and a consequent dent in the wallet when it’s time to order the parts. But that doesn’t always have to be the case, as it turns out that there are many ways to control a motor. [Bram] did it with a surprising part, a 74ACT139 dual 4-line demultiplexer.

A motor controller is little more than a set of switches between the supply rails and the motor terminals, and thus how it performs depends on a few factors such as how fast it can be switched, how much current it can pass, and how susceptible it is to any back EMF or other electrical junk produced by the motor.

In this particular application the motor was a tiny component in a BEAM robot, so the unexpected TTL motor controller could handle it. The original hack was done a few decades ago and it appears to have become a popular hack in the BEAM community.

This project is part of the Hackaday Component Abuse Challenge, in which competitors take humble parts and push them into applications they were never intended for. You still have time to submit your own work, so give it a go!

2025 Hackaday Component Abuse Challenge