RISC OS Gets An Update

There should be rejoicing among fans of the original ARM operating system this week, as the venerable RISC OS received its version 5.30 update. It contains up-to-date versions of the bundled software as well as for the first time, out-of-the-box WiFi support, and best of all, it can run on all Raspberry Pi models except the Pi 5. If you’ve not encountered RISC OS before, it’s the continuing development of the OS supplied with the first ARM product, the Acorn Archimedes. As such it’s a up-to-date OS but with an interface that feels like those of the early 1990s.

We like RISC OS here, indeed we reviewed the previous version this year, so naturally out came the Hackaday Pi 3 and an SD card to run it on. It’s as smooth and quick as it ever was, but sadly try as we might, we couldn’t get the Pi’s wireless interface to appear in the list of available network cards. This almost certainly has more to do with us than it does the OS, but it would have been nice to break free from the tether of the network cable. The included Netsurf 3.11 browser is nippy but a little limited, and just as it was during our review, sadly not capable of editing a Hackaday piece or we’d be using it to write this.

It’s great to see this operating system still under active development, and we can see that it so nearly fulfills our requirement here for a lightweight OS on the road. For those of us who used the original version, then called Arthur, it’s a glimpse of how desktop computing could, or perhaps even should, have been.

Screenshot of the GitHub Marketplace action listing, describing the extension

Giving Your KiCad PCB Repository Pretty Pictures

Publishing your boards on GitHub or GitLab is a must, and leads to wonderful outcomes in the hacker world. On their own, however, your board files might have the repo look a bit barren; having a picture or two in the README is the best. Making them yourself takes time – what if you could have it happen automatically? Enter kicad-render, a GitHub and GitLab integration for rendering your KiCad projects by [linalinn].

This integration makes your board pictures, top and bottom view, generated on every push into the repo – just embed two image links into your README.md. This integration is made possible thanks to the new option in KiCad 8’s kicad-cli – board image generation, and [linalinn]’s code makes KiCad run on GitHub/GitLab servers.

For even more bling, you can enable an option to generate a GIF that rotates your board, in the style of that one [arturo182] demo – in fact, this integration’s GIF code was borrowed from that script! Got a repository with many boards in one? There’s an option you could make work for yourself, too.

All you need to do is to follow a couple of simple steps; [linalinn] has documented both the GitHub and GitLab integration. We’ve recently talked about KiCad integrations in more detail, if you’re wondering what else your repository could be doing!

Ham Radio Paddles Cost Virtually Nothing

If you don’t know Morse code, you probably think of a radio operator using a “key” to send Morse code. These were — and still are — used. They are little more than a switch built to be comfortable in your hand and spring loaded so the switch makes when you push down and breaks when you let up. Many modern operators prefer using paddles along with an electronic keyer, but paddles can be expensive. [N1JI] didn’t pay much for his, though. He took paperclips, a block of wood, and some other scrap bits and made his own paddles. You can see the results in the video below.

When you use a key, you are responsible for making the correct length of dits and dahs. Fast operators eventually moved to a “bug,” which is a type of paddle that lets you push one way or another to make a dash (still with your own sense of timing). However, if you push the other way, a mechanical oscillator sends a series of uniform dots for as long as you hold the paddle down.

Modern paddles tend to work with electronic “iambic” keyers. Like a bug, you push one way to make dots and the other way to make dashes. However, the dashes are also perfectly timed, and you can squeeze the paddle to make alternating dots and dashes. It takes a little practice, but it results in a more uniform code, and most people can send it faster with a “sideswiper” than with a straight key.

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3D Printing In Custom PLA With A TPU Core

[Stefan] from CNC Kitchen explored an unusual approach to a multi-material print by making custom PLA filament with a TPU core to make it super-tough. TPU is a flexible filament whereas PLA is hard almost to the point of being brittle. The combo results in a filament with some unusual properties, inviting some thoughts about what else is possible.

Cross-section of 3D print using white PLA with a red TPU core.

[Stefan]’s video covers a few different filament experiments, but if you’d like to see the TPU-PLA composite you can skip ahead to 18:15. He first creates the composite filament by printing an oversized version on a 3D printer, then re-forming it by running it through a Recreator to resize it down to 1.75 mm.

We have seen this technique of printing custom filaments before, which is useful to create DIY multi-color filaments in small quantities right on a 3D printer’s print bed with no special equipment required. This is an effective method but results in filament with a hexagonal profile, which works but isn’t really ideal. By printing his custom composite at 4 mm diameter then resizing the filament down to 1.75 mm, [Stefan] was able to improve overall printability.

That being said, TPU and PLA have very different characteristics and don’t like to adhere to one another so the process was pretty fiddly. TPU-cored PLA might be troublesome and uncooperative to make, but it can be done with some patience and fairly simple equipment.

Despite the difficulties, test prints were pretty interesting. PLA toughness was roughly doubled and under magnification one can see a lattice of TPU strands throughout the prints which are unlike anything else. Check it out in the video, embedded below.

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Almost Making A Camera Sensor From Scratch

On our travels round the hardware world we’ve encountered more than one group pursuing the goal of making their own silicon integrated circuits, and indeed we’ve seen [Sam Zeloof] producing some of the first practical home-made devices. But silicon is simply one of many different semiconductor materials, and it’s possible to make working semiconductor devices in a less complex lab using some of the others. As an example, [Breaking Taps] has been working with copper (II) oxide, producing photodiodes, and coming within touching distance of a working matrix array.

The video below the break is a comprehensive primer on simple semiconductor production and the challenges of producing copper (II) oxide rather than the lower temperature copper (I) oxide. The devices made have a Schottky junction between the semiconductor and an aluminium conductor, and after some concerns about whether the silicon substrate is part of the circuit and even some spectacular destruction of devices, he has a working photodiode with a satisfying change on the curve tracer when light is applied. The finale is an array of the devices to form a rudimentary camera sensor, but sadly due to alignment issues it’s not quite there  yet. We look forward to seeing it when he solves those problems.

As we’ve seen before, copper oxide isn’t the only semiconductor material outside the silicon envelope.

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Tool-Building Mammals

It’s often said of us humans that we’re the only “tool-using mammals”. While not exclusive to the hacker community, a bunch of us are also “tool-building mammals” when we have the need or get the free time. I initially wanted to try to draw some distinction between the two modes, but honestly I think all good hackers do both, all the time.

We were talking about the cool variety of test probes on the podcast, inspired by Al Williams’ piece on back probes. Sometimes you need something that’s needle-thin and can sneak into a crimp socket, and other times you need something that can hold on like alligator clips. The infinite variety of jigs and holders that make it easier to probe tiny pins is nothing short of amazing. Some of these are made, and others bought. You do what you can, and you do what you need to.

You can learn a lot from looking at the professional gear, but you can learn just as much from looking at other hackers’ bodge jobs. In the podcast, I mentioned one of my favorite super-low-tech hacks: making a probe holder out of a pair of pliers and a rubber band to hold them closed. Lean this contraption onto the test point in question and gravity does the rest. I can’t even remember where I learned this trick from, but I honestly use it more than the nice indicator-arm contraptions that I built for the same purpose. It’s the immediacy and lack of fuss, I think.

So what’s your favorite way of putting the probe on the point? Home-made and improvised, or purpose-built and professional? Or both? Let us know!

How Does The Raspberry Pi Rack Up Against A Mini PC?

When the first Raspberry Pi came out back in 2012 it was groundbreaking because it offered a usable little Linux machine with the proud boast of a $25 dollar price tag. Sure it wasn’t the fastest kid on the block, but there was almost nothing at that price which could do what it did. Three leap years later though it’s surrounded by a host of competitors with similar hardware, and its top-end model now costs several times that original list price.

Meanwhile the cost of a “real” x86 computer such as those based upon the Intel N100 has dropped to the point at which it almost matches a fully tricked-out Pi with storage and peripherals, so does the Pi still hold its own? [CNX Software] has taken a look.

From the examples they use, in both cases the Intel machine is a little more expensive than the Pi, but comes with the advantage of all the peripherals, cooling, and storage coming built-in rather than add-ons. They rate the Pi as having the advantage on expandability as we’d expect, but the Intel giving a better bang for the buck in performance terms. From where we’re sitting the advantage of the Pi over most of its ARM competition has always been its good OS support, something which is probably exceeded by that on an x86 platform.

So, would you buy the Intel over the high-end Pi? Let us know in the comments.