SDRs have been a game changer for radio hobbyists, but for ham radio applications, they often need a little help. That’s especially true of SDR dongles, which don’t have a lot of selectivity in the HF bands. But they’re so darn cheap and fun to play with, what’s a ham to do?
[VK3YE] has an answer, in the form of this homebrew software-defined radio (SDR) helper. It’s got a few features that make using a dongle like the RTL-SDR on the HF bands a little easier and a bit more pleasant. Construction is dead simple and based on what was in the junk bin and includes a potentiometer for attenuating stronger signals, a high-pass filter to tamp down stronger medium-wave broadcast stations, and a series-tuned LC circuit for each of the HF bands to provide some needed selectivity. Everything is wired together ugly-style in a metal enclosure, with a little jiggering needed to isolate the variable capacitor from ground.
The last two-thirds of the video below shows the helper in use on everything from the 11-meter (CB) band down to the AM bands. This would be a great addition to any ham’s SDR toolkit.
Microcontroller dev boards are wonderfully useful items, in testament to which most of us maintain an ample collection of the things. But dragging one out to do a simple job can be a pain, what with making sure you have the whole toolchain set up to support the device, not to mention the inevitable need to solder or desolder header pins. Wouldn’t it be nice if there was a simple plug-and-play way to add a few bits of GPIO to your desktop or laptop machine?
[Nick Bild] thinks so, and came up with the USBgpio. The hardware in the dongle is pretty much what you’d expect — an Arduino Nano 33 IoT. Yes, you could just bust out a Nano and do this yourself, but [Nick] has done all the heavy lifting already. Eleven of the Nano’s IO pins plus 3.3V and ground are broken out to header pins that stick out of the 3D-printed enclosure, and the dongle is powered over the USB cable. [Nick] also built a Python library for the USBgpio, making it easy to whip up a quick program. You just import the library, define the serial port and baud rate, and the library takes care of the rest. The video below shows a quick blinkenlight test app.
Earth-shattering stuff? Perhaps not; [Nick] admits as much by noting the performance doesn’t really dazzle. But that’s hardly the point of the project, and if you need a couple of pins of IO on the desktop for a quick tactical project or some early-stage prototyping, USBgpio could be your friend. Continue reading “USB Dongle Brings Python-Controlled GPIO To The Desktop”→
As a professional writer, I rack up thousands of words a day. Too many in fact, to the point where it hurts my brain. To ease this burden, I choose my tools carefully to minimize obstructions as the words pour from my mind, spilling through my fingers on their way to the screen.
That’s a long-winded way of saying I’m pretty persnickety about my keyboard. Now, I’ve found out my favorite model has been discontinued, and I’ll never again know the pleasure of typing on its delicate keys. And I’m mad about it. Real mad. Because I shouldn’t be in this position to begin with!
If you’ve got a wireless keyboard or mouse, you’ve probably got a receiver dongle of some sort tucked away in one of your machine’s USB ports. While modern technology has allowed manufacturers to shrink them down to the point that they’re barely larger than the USB connector itself, they still stick out enough to occasionally get caught on things. Plus, let’s be honest, they’re kind of ugly.
For owners of the Framework laptop, there’s now a solution: the DongleHider+ by [LeoDJ]. This clever open source hardware project is designed to bring these little receivers, such as the Logitech Unifying Dongle, into one of the Framework’s Expansion bays. The custom PCB is designed with a large notch taken out to fit the dongle’s PCB, all you need to do is solder it in with four pieces of stiff wire.
Today, everything from your computer to your dryer has wireless communications built in, but devices weren’t always so unencumbered by wires. What to do when you have a legacy serial device, but no serial port on the computer you want to connect? [vahidyou] designed a wireless serial dongle to solve this conundrum.
Faced with a CNC that took instructions over serial port, and not wanting to deal with the cabling involved in a serial to USB adapter, [vahidyou] turned to an ESP8266 to let his computer and device talk wirelessly. The hand-made PCB connects via a 3.5 mm headphone jack to DB9 adapter which he describes in another article. While [vahidyou] did write a small Windows program for managing the device, it is probably easier to simply access it in a web browser from any device you have handy.
Want to see another wireless serial port application? This Palm Portable Keyboard Bluetooth dongle will let you type in comfort on the go, or you can use a PiModem to get your retrocomputer online!
At the time of this writing, the James Webb Space Telescope was perched upon its ride to space, ready for its much-delayed launch from the ESA spaceport in French Guiana. The $10 billion space observatory suffered one final delay (knocks on wood) when predictions of high winds aloft pushed it back from a Christmas Eve launch to a Christmas Day departure, at 12:20 UTC. Given the exigencies of the day, we doubt we’ll be able to watch the launch live — then again, past experience indicates we’ll still be wrapping presents at 4:20 PST. Either way, here’s hoping that everything comes off without a hitch, and that astronomers get the present they’ve been waiting many, many Christmases for.
In other space news, things are getting really interesting on Mars. The ESA announced that their ExoMars Trace Gas Orbiter has detected signs of water in the Valles Marineris. The satellite found a large area of increased hydrogen concentration in the top meter of Martian soil; the assumption is that the hydrogen comes from water, meaning that as much as 40% of the material in the region scanned may be water. If so, that’s a huge find, as we thought most of Mars’ water was locked in the polar regions. The Mariner Valley stretches more than 4,000 km just below the equator, and so may prove to be an important resource for future explorers.
Meanwhile, in Jezero crater, Perseverance has decided to upstage its rotorcraft sidekick for a change by finding signs of organic molecules on Mars. It’s not the first time organic compounds have been found — Perseverance’s cousin Curiosity found some too, ESA’s Mars Express mission spotted methane from on high, and then there were the equivocal but intriguing results from the Viking missions in the 1970s. But the latest evidence is really great news for the scientists who picked Jezero crater as a likely place to search for signs of past life on Mars. The organics found are not proof of life by any means, as there are many ways to make organic molecules abiotically. But then again, if you’re going to find evidence of life on Mars, you’ve got to start with detecting organics.
Back on Earth, getting your laptop stolen would be bad enough. But what if it got yoinked while it was unlocked? Depending on who you are and what you do with that machine, it could be a death sentence. That’s where BusKill could come in handy. It’s a hardware-software approach to securing a laptop when it — or you — suddenly goes missing. A dongle with a breakaway magnetic lanyard gets plugged into a USB port, and the other end of the lanyard gets attached to your person. If you get separated from your machine, the dongle sends customizable commands to either lock the screen or, for the sufficiently paranoid, nuke the hard drive. The designs are all up on GitHub, so check it out and think about what else this could be useful for.
If you like the look of low-poly models but hate the work involved in making them, our friend and Hack Chat alumnus Andrew Sink came up with a solution: an online 3D low-poly generator. The tool is pretty neat; it uses three.js and runs completely in-browser. All you have to do is upload an STL file and set sliders to get rid of as many triangles as you want. Great stuff, and fun to play with even if you don’t need to decimate your polygons.
And finally, what have you done with your oscilloscope for the last three years? Most of us can’t answer that except in the vaguest of terms, but then there’s DrTune, who took three years’ worth of screencaps from this Rigol DS1054z and strung them together into a 60-second movie. He swears he didn’t purposely sync the video to the soundtrack, which is “Flight of the Bumblebee” by Rimsky-Korsakov, but in some places it’s just perfect. See if you can guess what DrTune has been working on by watching the waveforms fly by. And watch for Easter eggs.
[Alta’s Projects] built a two-in-one cyberdeck that not only contains the requisite Raspberry Pi (a zero in this case) but also eschews a dumb LCD and uses an iPad mini 5 for a display.
We need to address the donor case right away. Some likely see this as heresy, and while we love to see vintage equipment lovingly restored, upcycling warms our hearts and keeps mass-produced plastic out of landfills too. The 1991 AST 386SX/20 notebook in question went for $45 on an online auction and likely was never destined for a computer museum.
Why is Cupertino’s iOS anywhere near a cyberdeck? If a touch screen is better than an LCD panel, a tablet with a full OS behind it must be even better. You might even see this as the natural outgrowth of tablet cases first gaining keyboards and then trackpads. We weren’t aware that either was possible without jailbreaking, but [Alta’s Projects] simply used a lighting-to-USB dongle and a mini USB hub to connect the custom split keyboard to the iPad and splurged on an Apple Magic Trackpad for seamless and wireless multi-touch input.
Internal USB Wiring, Charging Circuit, and Pi Zero
The video build (after the break) is light on details, but a quick fun watch with a parts list in the description. It has a charming casual feel that mirrors the refreshingly improvisational approach that [Altair’s Projects] takes to the build. We appreciate the nod to this cyberdeck from [Tinfoil_Haberdashery] who’s split keyboard and offset display immediately sprang to mind for us too. The references to an imagined “dystopian future” excuse the rough finish of some of the Dremel cuts and epoxy assembly. That said, apocalypse or not, the magnets mounted at both ends of the linear slide certainly are a nice touch.
