Aux-in On A 30 Year Old Boombox


[Michael] just sent us this nice example of some good ol’ fashioned radio hacking.

He originally received the radio from his grandmother, and while he doesn’t listen to the radio much, he felt he couldn’t just let it go to waste. So like any good hacker he cracked open the case and took a look inside.

The beauty with radios from the 80’s is the simplicity of it all. They typically have single layer PCBs and nice big components which makes it so much easier to tinker with.

He used a bench power supply to bypass the main transformer for safety’s sake, and began probing the various points. The cassettes audio output was the easiest to find, but unfortunately it required the play button to be activated. Not wanting to lose functionality (or have an annoying rattling cassette mechanism), he continued probing and eventually found similar wires coming from the radio part of the PCB. Upon further probing he discovered he could trick the radio band button so that the radio would be off, but the output could still be used. After that it was just a matter of wiring, soldering, and adding an auxiliary plug to the case.

We’ve covered lots of auxiliary port hacks in the past, but this one is a great example of saving old technology from the dump.

[Thanks Michael!]

Northrop Grumman Tests Space Tow Truck

In the early days, satellites didn’t stick around for very long. After it was launched by the Soviet Union in 1957, it only took about three months for Sputnik 1 to renter the atmosphere and burn up. But the constant drive to push ever further into space meant that soon satellites would remain in orbit for years at a time. Not that they always functioned for that long; America’s Explorer 1 remained in orbit for more than twelve years, but its batteries died after just four months.

Of course back then, nobody was too worried about that sort of thing. When you can count the number of spacecraft in Earth orbit on one hand, what does it matter if one of them stays up there for more than a decade? The chances of a collision were so low as to essentially be impossible, and if the satellite was dead and wasn’t interfering with communication to its functional peers, all the better.

The likelihood of a collision steadily increased over the years as more and more spacecraft were launched, but the cavalier approach to space stewardship continued more or less unchanged into the modern era. In fact, it might have endured a few more decades if companies like SpaceX weren’t planning on mega-constellations comprised of thousands of individual satellites. Concerned over jamming up valuable near-Earth orbits with so much “space junk”, modern satellites are increasingly being designed with automatic disposal systems that help make sure they are safely deorbited even in the event of a system failure.

That’s good news for the future, but it doesn’t help us with the current situation. Thousands of satellites are in orbit above the planet, and they’ll need to be dealt with in the coming years. The good news is that many of them are at a low enough altitude that they’ll burn up on their own eventually, and methods are being developed to speed up the process should it be necessary to hasten their demise.

Unfortunately, the situation is slightly more complex with communications satellites in geosynchronous orbits. At an altitude of 35,786 kilometers (22,236 miles), deorbiting these spacecraft simply isn’t practical. It’s actually far easier to maneuver them farther out into space where they’ll never return. But what if the satellite fails or runs out of propellant before the decision to retire it can be made?

That’s precisely the sort of scenario the Mission Extension Vehicle (MEV) was developed for, and after a historic real-world test in February, it looks like this “Space Tow Truck” might be exactly what we need to make sure invaluable geosynchronous orbits are protected in the coming decades.

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Putting Carbs On A Miata, Because It’s Awesome

Carburettors versus electronic fuel injection (EFI); automotive fans above a certain age will be well versed in the differences. While early EFI systems had their failings, the technology brought with it a new standard of reliability and control. By the early 1990s, the vast majority of vehicles were sold with EFI, and carburettors became a thing of the past.

The Mazda Miata was no exception. Shipping in 1989, it featured not only multiport fuel injection, but also a distributorless ignition system. Consisting of two coilpacks in a wasted spark configuration, with computer-controlled timing, the system was quite advanced for its time, especially for a budget sports car.

Despite the Miata’s technological credentials, those in the modified car scene tend to go their own way. A man by the name of Evan happened to be one such individual and decided to do just this — scrapping the EFI system and going with a retro carburetor setup. It was around this point that this I got involved, and mechanical tinkering ensued.

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E-ink Typewriter Is Refreshingly Slow

It’s pretty hard to use the internet to complete a task without being frequently distracted. For better or worse, there are rabbit holes at every turn and whilst exploring them can be a delight, sometimes you just need to focus on a task at hand. The solution could be in the form of distraction-blocking software, razor-sharp willpower, or a beautifully crafted modern “typewriter”. The constraint and restriction of a traditional typewriter appealed to [NinjaTrappeur], but the inability to correct typos and share content online was a dealbreaker. A hybrid was the answer, with a mechanical keyboard commanding an E-ink display driven by a Raspberry Pi.

The main point of interest in this build is the E-ink screen. Though it’s easy to acquire theses displays in small sizes, obtaining a screen greater than four inches proved to be a challenge. Once acquired, driving the screen over SPI was easy, but the refresh rate was horrific. The display takes three seconds to redraw, and whilst [NinjaTrappeur] was hoping to implement a faster “partial refresh”, he was unable to read the appropriate values from the onboard flash to enable manual control of the drawing stages. Needless to say, [NinjaTrappeur] asks if people have had success driving these displays at a more usable rate, and would love to hear from you if so.

Some auxiliary hacks come in the form of terminal emulator adaptation, porting the E-ink screen library from C++ to C, and capturing the keyboard input. A handmade wooden case finishes it off.

If it’s old-school typewriters that float your boat, we’ve got you covered: this solenoid-actuated typewriter printer eventually became a musical instrument, and this daisy wheel machine produces ASCII art from a live camera.

[Via Boing Boing]

Adding 3D Printer Power And Light Control To OctoPrint

OctoPrint is a great way to monitor your printer, especially with the addition of a webcam. Using a tablet or mobile phone, you can keep an eye on what the printer is doing from anywhere in the house (or world, if you take the proper precautions), saving you from having to sit with the printer as if it’s an infant. But simply watching your printer do its thing is only a small slice of the functionality offered by OctoPrint’s vast plugin community.

As [Jeremy S Cook] demonstrates, it’s fairly easy to add power control for the printer and auxiliary lighting to your OctoPrint setup. Being able to flick the lights on over the print bed is obviously a big help when monitoring it via webcam, and the ability to turn the printer off can provide some peace of mind after the print has completed. If you’re particularly brave it also means you could power on the printer and start a print completely remotely, but good luck if that first layer doesn’t go down perfectly.

In terms of hardware, you only need some 3.3V relays for the Raspberry Pi running OctoPrint to trigger, and an enclosure to put the wiring in. [Jeremy] uses only one relay in this setup to power the printer and lights at once, but with some adjustment to the software, you could get independent control if that’s something you’re after.

On the software side [Jeremy] is using an OctoPrint plugin called “PSU Control”, which is actually intended for controlling an ATX PSU from the Pi’s GPIO pins, but the principle is close enough to throw a relay. Other plugins exist which allow for controlling a wider away of devices and GPIO pins if you want to make a fully remote controlled enclosure. Plus you can always whip up your own OctoPrint plugin if you don’t find anything that quite meets your switching needs.

[Jeremy] previously documented his unique mount to keep his Raspberry Pi and camera pointed at his printer, which is naturally important if you want to create some cool videos with Octolapse.

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All The Badges Of DEF CON 26 (vol 1)

Two or three years back you would see a handful of really interesting unofficial badges at DEF CON. Now, there’s a deluge of clever, beautiful, and well executed badges. Last weekend I tried to see every badge and meet every badge maker. Normally, I would publish one megapost to show off everything I had seen, but this year I’m splitting it into volumes. Join me after the break for the first upload of the incredible badges of DC26!

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Turn A Cheap Bluetooth Speaker Into An Audio Receiver

Cheap Bluetooth speakers come in all different kinds of shapes and colors, and they let you conveniently stream music, for example from your mobile phone. For [mcmchris], they had one significant shortcoming though: while most of them come with some auxiliary input port as alternative audio source, they usually lack an audio output port that would let him route the audio to his more enjoyable big-speaker sound setup. Lucky for him, it’s a problem that can be fixed with a wire cutter and soldering iron, and so he simply turned his cheap speaker into a Bluetooth audio receiver.

After opening the speaker, [mcmchris] discovered a regular F-6188 Bluetooth audio module built around the BK8000L chip, with the audio jack connected to the chip’s aux input pins. Taking a close look at the PCB, the solution seemed obvious: cut the connection to the chip’s aux input pins, and connect the audio jack parallel to the audio signal itself. After some trial and error, the output pins of the on-board op amplifier seemed to provide the best audio signal for his shiny new output jack. You can see more details about the speaker’s inner life and a demonstration in the video after the break — in Spanish.

If the concept looks familiar to you, we’ve indeed seen a very similar approach to equip a Google Home Mini with an audio output jack before. The alternative is of course to just build a decent sized Bluetooth speaker yourself.

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