Author: Zoe Skyforest

3644 Articles

FM Transmitter Remotely Controlled Via ESP32

October 18, 2024 by 14 Comments

Imagine you’ve got an FM transmitter located some place. Wouldn’t it be mighty convenient if you could control that transmitter remotely? That way, you wouldn’t have to physically attend to it every time you had to change some minor parameters! To that end, [Ricardo Lima Caratti] built a rig to do just that.

The build is based around the QN8066—a digital FM transceiver built into a single chip. It’s capable of transmitting and receiving anywhere from 60 MHz to 108 MHz, covering pretty much all global FM stereo radio bands. [Ricardo] paired this chip with an ESP32 for command and control. The ESP32 hosts an HTTP server, allowing the administration of the FM transmitter via a web browser. Parameters like the frequency, audio transmission mode, and Radio Data Service (RDS) information can be controlled in this manner.

It’s a pretty neat little build, and [Ricardo] demonstrates it on video with the radio transmitting some field day content. We’ve seen some other nifty FM transmitters over the years, too. Video after the break.

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Teardowns Show Off Serious Satellite Hardware

October 18, 2024 by 14 Comments

As hackers, we’re always pulling stuff apart—sometimes just to see what it’s like inside. Most of us have seen the inside of a computer, television, and phone. These are all common items that we come into contact with every day. Fewer of us have dived inside real spacey satellite hardware, if only for the lack of opportunity. Some good gear has landed on [Don]’s desk over the years though, so he got to pulling it apart and peering inside.

[Don] starts us off with a gorgeous… box… of some sort from Hughes Aircraft. He believes it to be from their Space & Communications group, and it seems to have something to do with satellite communications work. Externally, he gleans that it takes power and data hookups and outputs RF to, something… but he’s not entirely sure. Inside, we get a look at the old 90s electronics — lots of through hole, lots of big chunky components, and plenty of gold plating. [Don] breaks down the circuitry into various chunks and tries to make sense of it, determining that it’s got some high frequency RF generators in the 20 to 40 GHz range.

Scroll through the rest of [Don]’s thread and you’ll find more gems. He pulls apart a microwave transmitter from Space Micro — a much newer unit built somewhere around 2008-2011. Then he dives into a mysterious I/O board from Broad Reach, and a very old Hughes travelling wave tube from the 1970s. The latter even has a loose link to the Ford Motor Company, believe it or not.

Even if you don’t know precisely what you’re looking at, it’s still supremely interesting stuff—and all very satellite-y. We’ve seen some other neat satellite gear pulled apart before, too. Meanwhile, if you’ve been doing your own neat teardowns, don’t hesitate to let us know!

MOTU Audio Interface Resurrected After Some Reverse Engineering

October 18, 2024 by 8 Comments

These days, when something electronic breaks, most folks just throw it away and get a new one. But as hackers, we prefer to find out what the actual problem is and fix it. [Bonsembiante] took that very tack when a MOTU brand audio interface wasn’t booting. As it turns out, a bit of investigative work led to a simple and viable fix.

The previous owner had tried to get the unit fixed multiple times without success. When it ended up on [Bonsembiante]’s bench, reverse engineering was the order of the day. Based around an embedded Linux system, there was lots to poke and prod at inside, it’s just that… the system wasn’t booting, wasn’t showing up over USB or Ethernet, or doing much of anything at all.

Extracting the firmware only revealed that the firmware was actually valid, so that was a dead end. However, after some work following the boot process along in Ghidra, with some external help, the problem was revealed. Something was causing the valid firmware to fail the bootloader’s checks—and with that fixed, the unit booted. You’ll have to read the article to get the full juicy story—it’s worth it!

We’ve seen [Bonsembiante’s] work here before, when they turned an old ADSL router into a functioning guitar pedal. Video after the break.

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Building A ZX Spectrum Using Only New Parts

October 17, 2024 by 29 Comments

Ah, the Sinclair ZX Spectrum. A popular computer in Britain and beyond, but now rather thin on the ground. If you can’t find one, fear not, for now—you can apparently build a new one with new parts! [TME Retro] is here to demonstrate how.

Before you get excited, no—Sinclair has not risen from the dead. Instead, it’s simply down to the state of the retrocomputing community. There are enough reproduction parts and components out there for the ZX Spectrum that it’s now possible to assemble the whole computer from new bits. You can get new cases and new mechanical keyboards, and a 100% compatible motherboard in the form of the Harlequin board. The latter even reproduces the unobtainable Spectrum ULA glue logic chip in raw logic!

It’s neat to see the ZX Spectrum live on decades after the production lines ground to a halt. We’ve seen similar feats achieved with the legendary Commodore 64; you’d think we had enough of them given they were the best-selling computer of all time. Video after the break.

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Redbox Is Dead, But The Machines Are Kind Of Hanging On

October 17, 2024 by 36 Comments

Redbox was a service for renting DVDs from automated kiosks. The business was going well until it wasn’t anymore, and then the company went bankrupt in July this year. And yet… the machines live on. At least, that’s according to YouTuber [Smokin’ Silicon], who spotted some remaining Redbox kiosks out and about. Including at his local Walmart!

Here’s the thing. There’s not one big switch at Redbox that turns all the machines off, and even if there was—nobody hit it the moment the company declared bankruptcy. Thus, when [Smokin’ Silicon] rocked up to Walmart, he was able to flick through the movies and even add one to cart for purchase. However, trying to complete the transaction failed—the kiosk eventually reported itself as out of service. That makes sense—you’d expect payment processing to be the first thing to go down.

However, other Redbox kiosks were different. A kiosk at a Food Lion location actually still worked—and [Smokin’ Silicon] was able to complete the transaction and walk away with a Black Adam disc! On a second trip, he was able to walk away with even more!

The rest of the video dives into Redbox lore and other posts online about the status of the company, software, and hardware. Apparently, someone on Reddit was claiming they had the Redbox kiosk OS available. Meanwhile, some users have had trouble returning their discs because the company is now defunct. However, [Smokin’ Silicon] was able to return his without issue. Ultimately, though, he recommends his viewers to go out and score as many DVDs and Blu Rays as possible from the machines since soon enough, they’ll be gone forever.

The fact is, businesses are big and Kafkaesque, the kiosks are scattered all over the country, and so it’s anybody’s guess if and when they stop working. Back when this website began, a redbox was something different entirely. Video after the break.

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Tiny LoRa GPS Node Relies On ESP32

October 17, 2024 by 10 Comments

Sometimes you need to create a satellite navigation tracking device that communicates via a low-power mesh network. [Powerfeatherdev] was in just that situation, and they whipped up a particularly compact solution to do the job.

As you might have guessed based on the name of its creator, this build is based around the ESP32-S3 PowerFeather board. The PowerFeather has the benefit of robust power management features, which makes it perfect for a power-sipping project that’s intended to run for a long time. It can even run on solar power and manage battery levels if so desired. The GPS and LoRa gear is all mounted on a secondary “wing” PCB that slots directly on to the PowerFeather like a Arduino shield or Raspberry Pi HAT. The whole assembly is barely larger than a AA battery.

It’s basically a super-small GPS tracker that transmits over LoRa, while being optimized for maximum run time on limited power from a small lithium-ion cell. If you’re needing to do some long-duration, low-power tracking task for a project, this might be right up your alley.

LoRa is a useful technology for radio communications, as we’ve been saying for some time. Meanwhile, if you’ve got your own nifty radio comms build, or anything in that general milleu, don’t hesitate to drop us a line!

How To Make Conductive Tin Oxide Coatings On Glass

October 11, 2024 by 19 Comments

Glass! It’s, uh, not very conductive. And sometimes we like that! But other times, we want glass to be conductive. In that case, you might want to give the glass a very fine coating of tin oxide. [Vik Olliver] has been working on just that, in hopes he can make a conductive spot on a glass printing bed in order to use it with a conductive probe.

[Vik’s] first attempt involved using tin chloride, produced by dissolving some tin in a beaker of hydrochloric acid. A droplet of this fluid was then dropped on a glass slide that was heated with a blowtorch. The result was a big ugly white splotch. Not at all tidy, but it did create a conductive layer on the glass. Just a thick, messy one. Further attempts refined the methodology, and [Vik] was eventually able to coat a 1″ square with a reasonably clear coating that measured an edge-to-edge resistance around 8 megaohms.

If you’re aware of better, easier, ways to put a conductive coating on glass, share them below! We’ve seen similar DIY attempts at this before, too. If you’ve been cooking up your own interesting home chemistry experiments (safely!?) do let us know!