Tiny Transceiver Gets It Done With One Transistor

When we first spotted the article about a one-transistor amateur radio transceiver, we were sure it was a misprint. We’ve seen a lot of simple low-power receivers using a single transistor, and a fair number of one-transistor transmitters. But both in one package with only a single active component? Curiosity piqued.

It turns out that [Ciprian Popica (YO6DXE)]’s design is exactly what it says on the label, and it’s pretty cool to boot. The design is an improvement on a one-transistor transceiver called “El Pititico” and is very petite indeed. The BOM has only about fifteen parts including a 2N2222 used as a crystal-controlled oscillator for both the transmitter and the direct-conversion receiver, along with a handful of passives and a coupe of hand-wound toroidal inductors. There’s no on-board audio section, so you’ll have to provide an external amplifier to hear the signals; some might say this is cheating a bit from the “one transistor” thing, but we’ll allow it. Oh, and there’s a catch — you have to learn Morse code, since this is a CW-only transmitter.

As for construction, [Ciprian] provides a nice PCB  layout, but the video below seems to show a more traditional “ugly style” build, which we always appreciate. The board lives in a wooden box small enough to get lost in a pocket. The transceiver draws about 1.5 mA while receiving and puts out a fairly powerful 500 mW signal, which is fairly high in the QRP world. [Ciprian] reports having milked a full watt out of it with some modifications, but that kind of pushes the transistor into Magic Smoke territory. The signal is a bit chirpy, too, but not too bad.

We love minimalist builds like these; they always have us sizing up our junk bin and wishing we were better stocked on crystals and toroids. It might be good to actually buckle down and learn Morse too.

Continue reading “Tiny Transceiver Gets It Done With One Transistor”

Home Automation Panel Looks Industrial

Modern tech is great, but we have to admit that we sometimes miss when electronic things looked complicated. A modern computer looks dull compared to, say, an IBM 360. Control rooms now look no different than a stock trading room, instead of being full of indicators, knobs, and buzzers. [BorisDigital] must have some of those same feelings. He built a very cool control panel for his Home Assistant setup. He based it somewhat on a jet cockpit and a little on a nuclear plant control room, and the result, as you can see in the video below, is great.

This is less of a how-to video and more of an inspirational one. After all, you won’t have the same setup, but there are many details about how it was constructed with a Raspberry Pi, 3D printing, and control of the Home Assistant via web services.

Continue reading “Home Automation Panel Looks Industrial”

Iron Man Arc Reactor Clock Is A Stylish Piece

Iron Man was the film that kicked off the Marvel craze, and is widely regarded to be better than a lot of the movies that followed. If you’re a big fan of the OG, you’re probably already drowning in Iron Man helmets and arc reactor doo-dads, but here’s one more for you. After all, you probably don’t have an arc reactor clock yet.

The build comes to us from [jerome95]. It starts with an off-the-shelf ring of addressable LEDs, which serves as the basic defining dimension for the project. The ring gets a 3D printed support structure and some non-functional copper coils to complete the basic “arc reactor” look. Inside the center sits a small 7-segment display which displays the time under the command of an ESP32. It uses a network time server so it’s always on the dot.  Meanwhile, if you’re not a fan of the 7-segment version, you can always try the OLED variant of the build instead.

It’s not a complicated build; that could have been easily achieved, though. The builder could have displayed the time by making the LEDs flash different colors, instead of using a 7-segment display. However, that would have made a far more confounding clock. As it is, this design would make an excellent gift for any Marvel fan. Particularly those that acknowledge the supremacy of the film that started it all.

Continue reading “Iron Man Arc Reactor Clock Is A Stylish Piece”

Hackaday Podcast Episode 279: Solar Flares, Flash Cells, And Free Airline WiFi

Get your weekly fix of great hacks with your guides, Elliot Williams and Al Williams. This week, the guys talk about hacking airline WiFi, vanishing cloud services, and hobbies adjacent to hacking, such as general aviation. Things go into the weird and wonderful when the topic turns to cavity filters, driving LEDs with a candle, and thermite.

Quick hacks? Everything from vintage automated telescopes to home fusion reactors and ham radio mobile from a bicycle. Then there’s the can’t miss articles about the Solar Dynamics Observatory and an explainer about flash memory technology.

Check out the links below and leave your favorite hack of the week in the comments below!

As always, this week’s episode is freeze-dried as an MP3 for your convenience.

Continue reading “Hackaday Podcast Episode 279: Solar Flares, Flash Cells, And Free Airline WiFi”

A batarang-shaped keyboard with a Batmobile that we wish was a mouse.

Holy Keyboard Case, Batman!

Whoever thought a keyboard could look so sinister? Well, [rain2] aka [AffectionateWin7178], that’s who. Vengeance is the sixth keyboard they’ve designed, and let’s just say we wouldn’t mind seeing the other five.

This is a takeoff of Zazu, a custom case printed for the monoblock split designed by [AlSaMoMo]. A friend of [rain2] made a ZMK PCB for the Zazu about a month ago, and they dreamed up the case design together. Among our first questions were of course, how do you type without those bat wings digging into your palms? But evidently, they are designed not to get in the way at all during use.

We particularly like the gold skirt around the edge which joins the two printed halves. It goes nicely with the bank vault elements like the dial around the trackball and the five-way switch that resembles a handle. And yeah, we wish the Batmobile was a mouse, too. While it seems that [rain2] hasn’t released the STLs for the case, you can find the ZMK Zazu repo on GitHub. Happy designing! As always, let us know what you come up with.

Here’s another BAT keyboard you might be interested in.

This Week In Security: Blast-RADIUS, Gitlab, And Plormbing

The RADIUS authentication scheme, short for “Remote Authentication Dial-In User Service”, has been widely deployed for user authentication in all sorts of scenarios. It’s a bit odd, in that individual users authenticate to a “RADIUS Client”, sometimes called a Network Access Server (NAS). In response to an authentication request, a NAS packages up the authentication details, and sends it to a central RADIUS server for verification. The server then sends back a judgement on the authentication request, and if successful the user is authenticated to the NAS/client.

The scheme was updated to its current form in 1994, back when MD5 was considered a cryptographically good hash. It’s been demonstrated that MD5 has problems, most notably a chosen-prefix collision attack demonstrated in 2007. The basis of this collision attack is that given two arbitrary messages, it is possible to find a pair of values that, when appended to the end of those messages, result in matching md5 hashes for each combined message. It turns out this is directly applicable to RADIUS.
Continue reading “This Week In Security: Blast-RADIUS, Gitlab, And Plormbing”

DIY Spacer Increases FDM Flow Rate For Faster, Better Printing

The host of problems to deal with when you’re feeling the need for FDM speed are many and varied, but high on the list is figuring out how to melt filament fast enough to accommodate high flow rates. Plus, the filament must be melted completely; a melty outside and a crunchy inside might be good for snacks, but not for 3D printing. Luckily, budget-minded hobbyists can build a drop-in booster to increase volumetric flow using only basic tools and materials.

[aamott]’s booster, which started life as a copper screw, is designed to replace the standard spacer in an extruder, with a bore that narrows as the filament gets closer to the nozzle to ensure that the core of the filament melts completely. Rather than a lathe, [aamott]’s main tool is a drill press, which he used to drill a 0.7 mm bore through the screw using a PCB drill bit. The hole was reamed out with a 10° CNC engraving bit, generating the required taper. After cutting off the head of the screw and cleaning up the faces, he cut radial slots into the body of the booster by threading the blade of a jeweler’s saw into the bore. The result was a bore wide enough to accept the filament on one end, narrowing to a (roughly) cross-shaped profile at the other.

Stacked up with a couple of knock-off Bondtech CHT nozzles, the effect of the booster was impressive — a 50% increase in flow rate. It’s not bad for a prototype made with simple tools, and it looks a little easier to build than [Stefan]’s take on the same idea.

Continue reading “DIY Spacer Increases FDM Flow Rate For Faster, Better Printing”