Steampipe: All SQL All The Time

February 19, 2024 by 23 Comments

Although modern Linux has slightly shifted, the old Unix mantra was: everything’s a file. With Steampipe, a better saying might be: everything’s a SQL table. The official tagline is “select * from cloud” which also works. The open-source program relies on plugins, and there are currently 140 sources ranging from GitHub to Google Sheets and more.

There are command line interfaces for the major platforms. You can also add the system to PostgresSQL or SQLite for even more SQL goodness. Continue reading “Steampipe: All SQL All The Time” →

Linux Fu: Forward To The Past!

February 19, 2024 by 5 Comments

Ok, so the title isn’t as catchy as “Back to the Future,” but my guess is a lot of people who are advanced Linux users have — at least — a slight interest in retrocomputing. You’d like an Altair, but not for $10,000. You can build replicas of varying fidelities, of course. You can also just emulate the machine or a similar CP/M machine in software. There are many 8080 or Z80 emulators out there, ranging from SIMH to MAME. Most of these will run on Linux or — at the least — WINE. However, depending on your goals, you should consider RunCPM. Why? It runs on many platforms, including, of course, Linux and other desktop systems. But it also will work with the Arduino, Teensy, ESP32, or STM32 processors. There is also experimental support for SAM4S and Cyclone II FPGAs.

It’s pretty interesting to have one system that will work across PCs and embedded hardware. What’s more is that, at least on Linux, the file system is directly translated (sort of), so you don’t have to use tricks or special software to transfer files to and from CP/M. It is almost like giving Linux the ability to run CP/M software. You still have to have virtual disks, but they are nothing more than directories with normal files in them.

Goals

Of course, if your goal is to simulate a system and you want to have 180 kB floppies or whatever, then the direct file system isn’t a benefit. But if you want to use CP/M software for education, nostalgia, or cross-development, this is the way to go, in my opinion.

It isn’t just the file system, either. If you need a quick utility inside your bogus CP/M environment, you can write it in Lua, at least on desktop systems. On the Arduino, you can access digital and analog I/O. Theoretically, you could deploy an embedded Altair for some real purpose fairly cheaply. Continue reading “Linux Fu: Forward To The Past!” →

A Classroom-Ready Potentiometer From Pencil And 3D Prints

February 19, 2024 by 18 Comments

If you need a potentiometer for a project, chances are pretty good that you’re not going to pick up a pencil and draw one. Then again, if you’re teaching someone how a variable resistor works, that old #2 might be just the thing.

When [HackMakeMod] realized that the graphite in pencil lead is essentially the same thing as the carbon composition material inside most common pots, the idea for a DIY teaching potentiometer was born. The trick was to build something to securely hold the strip while making contact with the ends, as well as providing a way to wipe a third contact across its length. The magic of 3D printing provided the parts for the pot, with a body that holds a thin strip of pencil-smeared paper securely around its inner diameter. A shaft carries the wiper, which is just a small length of stripped hookup wire making contact with the paper strip. A clip holds everything firmly in place. The video below shows the build process and the results of testing, which were actually pretty good.

Of course, the construction used here isn’t meant for anything but demonstration purposes, but in that role, it performs really well. It’s good that [HackMakeMod] left the body open to inspection, so students can see how the position of the wiper correlates to resistance. It also makes it easy to slip new resistance materials in and out, perhaps using different lead grades to get different values.

Hats off to a clever build that should be sure to help STEM teachers engage their students. Next up on the lesson plan: a homebrew variable capacitor.

Continue reading “A Classroom-Ready Potentiometer From Pencil And 3D Prints” →

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The 200% Typewriter

February 19, 2024 by 3 Comments

Image by [jefmer] via Hackaday.IO
You know, the really sad truth about cyberdecks and cyberdeck-adjacent builds is that many of them just end up on the shelf, collecting dust while waiting for the dystopian future. Well, not this one. No, [jefmer] says their Portable Pi sees daily use, and even comes along on the go.

Since [jefmer] is “temperamentally unsuited to 3D printing”, the Pi 4B and its accessories are nestled in a rugged, splash-proof case under some acrylic sheets. One of those accessories, the keyboard, is a KPrepublic BM40 with Gateron Yellows. In order to get used to the number and symbols layer, [jefmer] laid down some great-looking labels above the keyboard.

Although the build started with an SD card for storage, [jefmer] has since upgraded to a 120 GB SSD. This required a beefy battery pack, but the difference is that it gets around four hours of power versus five hours when using an SD card.

Continue reading “Keebin’ With Kristina: The One With The 200% Typewriter” →

Not A FrogPad But Close

February 19, 2024 by 7 Comments

While you might think one-handed keyboards are a niche item, if you have reduced function in one hand or you only have one hand, they are pretty important. [Kian] was getting ready for surgery that would put his left arm out of commission for a while, which spurred the construction of a one-handed keyboard inspired by FrogPad.

There was a time when creating a new keyboard would have been a significant task. These days, it is reasonably easy and [Kian] simply repurposed an existing kit for a split keyboard. Using just half the board was easy since it is made in two parts already.

There have been many attempts at building effective one-handed input devices over the years, and the circa 2002 FrogPad is one of the better devices. Like most one-handed keyboards, it uses layers. The top layer has the most common keystrokes to minimize the number of layer changes required to type common text.

Continue reading “Not A FrogPad But Close” →

Printable Keyboard Dock Puts Steam Deck To Work

February 19, 2024 by 7 Comments

Whether or not you’re into playing video games, you have to admit, that the Steam Deck is a pretty interesting piece of hardware. We’ve seen hackers jump through all sorts of uncomfortable hoops to get Linux running on their mobile devices in the past. The fact that you can pick up a fairly powerful x86 handheld computer right now for a reasonable amount of money is certainly exciting. The Linux steam deck gets even more enticing when you consider the software support it enjoys thanks to its large and vibrant user community. No wonder we’ve started to see them dotting the workbenches during Hackaday Supercon.

If there’s a downside, it’s that the Steam Deck was very clearly designed to be a handheld gaming system, not a portable computer. Sure you can plug in an external monitor and keyboard, but things can quickly become ungainly. This is why a printable dock from [a8ksh4] caught our eye.

It’s officially designed to let you mate the Steam Deck with the Corne keyboard, a split ergonomic design that’s graced these pages a few times in the past. [A8ksh4] has included links for all the hardware you’ll need outside the printed parts, from the hinges and keyboard PCBs, all the way to the keycaps and stainless steel screws. If you’re looking for a turnkey experience, this is it.

Continue reading “Printable Keyboard Dock Puts Steam Deck To Work” →

Double Fed Induction Motors: Clever Motor Control Through Frequency

February 18, 2024 by 27 Comments

Somewhere in most engineering educations, there’s a class on induction motors. Students learn about shaded-pole motors, two-phase and three-phase motors, squirrel cage motors, and DC-excited motors. It’s a pre-requisite for then learning about motor controllers and so-called brushless DC motors. [Jim Pytel] takes this a step further in a series of videos, in which he introduces the doubly fed induction motor. If a conventional three-phase motor can have its coils in either rotor or stator, here’s a motor with both. The special tricks with this motor come in feeding both rotor and stator with separate frequencies, at which point their interactions have useful effects on the motor speed.

There are two videos, both of which we’ve put below the break. Understanding the complex interaction of the two sets of magnetic fields is enough to make anyone’s brain hurt, but the interesting part for us is that the motor can run faster than either of the two drive frequencies.

Sadly we’re not aware of any easily available motors using this configuration, so we don’t think it will be possible to easily experiment. But if you want to amaze your friends with an in-depth knowledge of motors, take a look at the videos below.

Continue reading “Double Fed Induction Motors: Clever Motor Control Through Frequency” →