A PCB ruler is a common promotional item, or design exercise. Usually they have some sample outlines and holes as an aid to PCB design, but sometimes they also incorporate some circuitry. [Clovis Fritzen] has given us an ingenious example, in the form of a PCB ruler with a built-in thermometer.
This maybe doesn’t have the fancy seven segment or OLED display you were expecting though, instead it’s an ATtiny85 with a lithium cell, the minimum of components, a thermistor for measurement, and a couple of LEDs that serve as the display. These parts are interesting, because they convey the numbers by flashing. One LED is for the tens and the other the units, so count the flashes and you have it.
We like this display for its simplicity, we can see the same idea could be used in many other places.On a PCB ruler, it certainly stands apart from the usual. It has got plenty of competition though.
A few weeks ago we brought you news of a new palmtop computer for hackers, powered by the new Espressif ESP32-P4 application processor. The Tanmatsu (Japanese for “Terminal”) is a compact handheld device with a QWERTY keyboard and an 800×480 DSI display, and while it currently exists at the final prototype stage there is a pre-order page upon which you can reserve an early production model for yourself. We’ve been lucky enough to be invited to give one a close-up inspection, so it was time to hot-foot it on the train to a Dutch hackerspace in order to bring you a preview.
A Little History, And First Impressions
Recesses in the case fit well against the hands.
Before looking at the device, it’s time for a little history. The Tanmatsu has its origin in badge.team, the Netherlands-based group that has produced so many European event badges over the years, and it was destined to eventually become the badge for the upcoming WHY2025 hacker camp. As sometimes happens in any community there has been a significant difference of opinion between the event orga and the badge.team folks that it’s inappropriate to go into here, so now it exists as a standalone project. It’s destined to be open-source in its entirety including hardware and software (and we will hold them to that, never fear), but because of the events surrounding its conception the full repositories will be not be made public until some time late in the summer.
Picking the Tanmatsu up and holding it, it’s a rectangular slab a bit larger and thicker than a CD case with that QWERTY keyboard and display on its front face, an array of ports including an SMA socket for a LoRA antenna on its sides, and an expansion connector on its rear. It has a sandwich construction, with a PCB front face, a 3D printed spacer, the PCB itself, and a 3D printed back cover all held together with a set of screws. The recesses on its bottom edge and the lower halves of the sides locate neatly with fingers and thumbs when it’s held in two hands for two-thumb typing. The keyboard is a silicone moulding as is common on this type of device, and while the keys are quite small it was not difficult to type on it. The display meanwhile feels of much higher quality than the SPI parts previously seen on badges. Continue reading “A Closer Look At The Tanmatsu”→
Many decades ago, when soldering was an activity more often associated with copper fabrication than with electronics, a soldering iron would have been a large lump of copper on a shaft with a wooden handle. You would heat it in a gas flame, and use its pointed end for your soldering. Electric irons have made this a thing of the past, but the basic idea is still one with some merit. [Shake the Future] is here with a modern take on such an iron, one that is heated in the microwave oven.
The business end of the iron is a normal soldering iron bit, but behind it is a piece of sintered silicon carbide wrapped in ceramic fibre and covered with Kapton tape and a high-temperature-resin 3D printed shield. On the back of that is a 3D-printed handle. The whole thing is put in the microwave oven for a few tens of seconds to heat to temperature, and thereafter, you have however long the thermal mass of the silicon carbide holds the temperature in which to do your soldering.
It’s an interesting idea that we can see has some use in situations where you need an iron for a quick job away from your bench but within reach of the kitchen. We like the lateral thinking, and it’s certainly fascinating to see the construction. But in an age of USB-C power packs and irons we have more convenient soldering on the go, so we’re not sure how useful it would be to us.
In the mid 1980s, there was a rash of 16-bit computers entering the market. One of them stood head and shoulders above the rest: Commodore’s Amiga 1000. It had everything that could reasonably be stuffed into a machine of the period, and multimedia capabilities the rest wouldn’t catch up on for years. [Celso Martinho] has managed to secure one of those first machines, and has shared his tale of bringing it back to life.
The post is as much a love letter to the Amiga and review of A1000 peripherals as it is a restoration, which makes it a good read for retrocomputing enthusiasts. He recapped it and it wouldn’t boot, the solution of which turned out to be a reminder for the rest of us.
The machine had a RAM upgrade in the form of a daughterboard under the processor, its pins had weakened the leaves of the processor socket so it wouldn’t make contact. So don’t forget to replace sockets as well as capacitors.
The resulting machine is much faster thanks to a modern upgrade with a much quicker processor, memory, and an SD card for storage. He goes into some of the other upgrades available today, all of which would have had early-1990s-us salivating. It’s fair to say that in 2025 an A1000 is more 40-year-old curio than useful modern computer, but we can’t fail to admit to a bit of envy. The Amiga holds a special affection, here.
Though it is many decades since paper tape was commonly used as a data input or storage medium, it still holds a fascination for many who work with computers. Over the years we’ve featured more than one paper tape related project, and the latest to come out way is [ColemanJW2]’s 8-bit ASCII paper tape generator.
It’s natural to expect when talking about a paper tape generator that a machine of some type will emerge, probably with a large reel of tape, a whirring mechanical punch, and a big box of paper confetti. This one however is different, because it exists in software and produces an SVG file to cut the tape with a laser cutter. Common workshop equipment in 2025, but the stuff of science fiction when paper tape was current.
The software is a Python script, which has a friendly GUI. It applies 8-bit ASCII to the tape, and supports control codes and ANSI escape sequences. There’s a very short demonstration video of a tape being cut, which we’ve placed below the break.
You can work with a part for many decades, and still learn something new about it. At least we can, and we don’t mind admitting it. Take film capacitors — we all know they aren’t a polarized part like an electrolytic capacitor is, but as [TheDannVal] points out, that doesn’t mean both their leads are the same.
This might sound counterintuitive, but if you consider for a moment their construction it makes sense. A film capacitor is made from two strips of foil with a strip of plastic film between then, rolled up tightly into a cylinder. One of the pieces of foil that forms one side of the capacitor ends up on the outside of the cylinder, and thus forms the shield for the other. Thus if that side isn’t connected to the lower impedance side of whichever circuitry it resides in, it can pick up noise, while the inside strip of foil can not. It’s so obvious when demonstrated, but we have to admit to never having considered it before. Some film capacitors have a line marked on them to denote the connection forming the shield, for those that don’t he provides a couple of methods for detecting it.
The full video is below the break, and maybe you too can now pay attention to your capacitors for lower noise audio circuitry.
We’re used to those high voltage projects which use a self-oscillating transformer circuit with a TV flyback winding, and we have even at times railed against them for their inefficiency compared to a real flyback circuit using the same parts. But what happens if the same idea is used to create a low voltage instead of a high one? [D. Creative] has a soldering gun project doing just this, making a low voltage at a very high current.
The video of the project is below the break, and while electrically it’s nothing unexpected, we’re taken by the quality of the build. All the parts come from scrap electronics, the main transformer is three ferrite cores with a piece of copper busbar as the secondary. The circuitry is built dead bug style, and it’s housed in a gun-style case made by hand from sheet Perspex. It takes 12 volt power from a laptop power supply, and feeds it to the oscillator which is perched up at the back of the device. The transformer fits in the “barrel”, and a pair of large capacitors fit in the handle. We expect it to get hot, but the duty cycle on these devices in use is probably low enough to keep it from melting.
We like anything that uses scrap parts to make something useful, and we’re particularly taken with the casing of this one. It looks as though the parts come from old switch mode power supplies, something we’ve been known to rob ourselves.
