PCB of the antenna about to be modded, with components desoldered and different parts of the circuit highlighted

Make A GPS Antenna Compatible With Same Manufacturer’s Receiver

April 3, 2024 by 9 Comments

GPS can be a bit complex of a technology – you have to receive a signal below the noise floor, do quite a bit of math that relies on the theory of relativity, and, adding insult to injury, you also have to go outside to test it. Have you ever wondered how GPS antennas work? In particular, how do active GPS antennas get power down the same wire that they use to send signal to the receiver? Wonder not, because [Tom Verbeure] gifts us a post detailing a mod letting a fancy active GPS antenna use a higher-than-expected input voltage.

[Tom]’s post has the perfect amount of detail – enough pictures to illustrate the entire journey, and explanations to go with all of it. The specific task is modifying a Symmetricom antenna to work with a Symmetricom GPS receiver, which has a puzzling attribute of supplying 12V to the antenna instead of more common 3.3V or 5V. There’s a few possible options detailed, and [Tom] goes for the cleanest possible one – replacing the voltage regulator used inside of the antenna.

With a suitable replacement regulator installed and a protection diode replaced, the antenna no longer registers as a short circuit, and gets [Tom] a fix – you, in turn, get a stellar primer on how exactly active GPS antennas work. If your device isn’t ready to use active GPS antennas, [Tom]’s post will help you understand another GPS antenna hack we covered recently – modifying the Starlink dish to use an active antenna to avoid jamming on the frontlines.

The Most Annoying Thing On The Internet Isn’t Really Necessary

March 29, 2024 by 31 Comments

We’re sure you’ll agree that there are many annoying things on the Web. Which of them we rate as most annoying depends on personal view, but we’re guessing that quite a few of you will join us in naming the ubiquitous cookie pop-up at the top of the list. It’s the pesky EU demanding consent for tracking cookies, we’re told, nothing to do with whoever is demanding you click through screens and screens of slider switches to turn everything off before you can view their website.

Now [Bite Code] is here to remind us that it’s not necessary. Not in America for the somewhat obvious reason that it’s not part of the EU, and perhaps surprisingly, not even in the EU itself.

The EU does have a consent requirement, but the point made in the article is that its requirements are satisfied by the Do Not Track header standard, an HTTP feature that’s been with us since 2009 but which almost nobody implemented so is now deprecated. This allowed a user to reject tracking at the browser level, making all the cookie popups irrelevant. That popups were chosen instead, the article concludes, is due to large websites preferring to make the process annoying enough that users simply click on the consent button to make it go away, making tracking much more likely. We suspect that the plethora of cookie popups also has something to do with FUD among owners of smaller websites, that somehow they don’t comply with the law if they don’t have one.

So as we’d probably all agree, the tracking cookie situation is a mess. This post is being written of Firefox which now silos cookies to only the site which delivered them, but there seems to be little for the average user stuck with either of the big browsers. Perhaps we should all hope for a bit more competition in the future.

Cookies header: Lisa Fotios, CC0.

NASA Engineers Poke Voyager 1 And Receive Memory Dump

March 16, 2024 by 59 Comments

For months, there has been a rising fear that we may have to say farewell to the Voyager 1 spacecraft after it began to send back garbled data. Now, in a sudden twist, Voyager 1 sent back a read-out of the Flight Data Subsystem (FDS) memory after a “poke” command, which both gives some hope that the spacecraft is in a better condition than feared while also allows engineers to dig through the returned memory read-out for clues. Although this data was not sent in the format that the FDS is supposed to use when it’s working correctly, it’s nevertheless readable.

It was previously suspected that the issue lay with the telemetry modulation unit (TMU), but has since been nailed down to the FDS itself.  This comes after NASA engineers have been updating the firmware on both spacecraft to extend their lifespan, but it’s too early to consider this as a possible reason. Now, as a result of the “poke” instruction – which commands the computer to try different sequences in its firmware in case part of it has been corrupted – engineers can compare it to previous downloads to hopefully figure out the cause behind the FDS problems and a possible solution.

Inspired by this news of the decoded memory download, Nadia Drake – daughter of Frank Drake – wrote about how it affects not only the engineers who have worked on the Voyager mission for the past decades but also her own thoughts about the two Voyager spacecraft. Not only do they form a lasting reminder of her father and so many of his colleagues, but the silence that would follow if we can no longer communicate with these spacecraft would be profound. Still, this new hope is better than the earlier news about this plucky little spaceship.

Thanks to [Mark Stevens] for the tip.

A Very 21st Century Receiver For A Very 20th Century Band

January 9, 2024 by 24 Comments

The FM broadcast band has been with us since the middle of the 20th century, and despite many tries to unseat it, remains a decent quality way to pick up your local stations. It used to be that building an FM broadcast receiver required a bit of RF know-how, but the arrival of all-in-one receiver chips has made that part a simple enough case of including a part. That’s not to say that building a good quality FM broadcast receiver in 2024 doesn’t involve some kind of challenge though, and it’s one that [Stefan Wagner] has risen to admirably with his little unit.

Doing the RF part is an RDA5807MP single chip radio, but we’d say the center of this is the CH32V003 RISC-V microcontroller and its software. Twiddling the dial is a thing of the past, with a color display and all the computerized features you’d expect. Rounding it off in the 3D printed case is a small speaker and a Li-Po pouch cell with associated circuitry. This really is the equal of any commercially produced portable radio, and better than many.

Even with the all-in-one chips, there’s still fun in experimenting with FM the old way.

Building A GPS Receiver From The Ground Up

January 2, 2024 by 11 Comments

One of the more interesting facets of GPS is that, at least from the receiver’s point-of-view, it’s a fairly passive system. All of the information beamed down from the satellites is out in the ether, all the time, free for anyone on the planet to receive and use as they see fit. Of course you need to go out and buy a receiver or, alternatively, possess a certain amount of knowledge to build a circuit that can take those signals and convert them into something usable. Luckily, [leaning_tower] has the required knowledge and demonstrates it with this DIY GPS receiver.

This receiver consists of five separate circuit boards, all performing their own function. The first, a mixer board, receives the signal via an active antenna and converts it to a lower frequency. From there it goes to a second mixer and correlation board to compare the signal to a local reference, then a signal processing board that looks at this intermediate frequency signal to make sense of the data its seeing. Finally, an FPGA interfacing board ties everything together and decodes the information into a usable form.

Dealing with weak signals like this has its own set of challenges, as [leaning_tower] found out. The crystal oscillator had to be decapped and modified to keep from interfering with the GPS radio since they operated on similar frequencies. Even after ironing out all the kinks, the circuit takes a little bit of time to lock on to a specific satellite but with a second GPS unit for checking and a few weeks of troubleshooting, the homebrew receiver is up and running. It’s an impressive and incredibly detailed piece of work which is usually the case with sensitive radio equipment like GPS. Here’s another one built on a Raspberry Pi with 12 channels and a pretty high accuracy.

DIY Tube Lights Look Amazing For Just $50 A Piece

December 31, 2023 by 7 Comments

It’s the future. We should have weird glowy lights everywhere, all over our homes, cars, and businesses. In the automotive world, luxury automakers are doing their part with LED ambient lighting systems, but the rest of us have to step up. [Super Valid Designs] has developed an excellent modular DMX lighting rig that’s fit for this purpose; the rest of us just have to get to work and build our own!  (Video, embedded below.)

The design relies on hot-swapping powered bases that let a variety of different lights to be swapped in as needed. They use a custom four-pin socket designed by [Super Valid Designs] using PVC and ABS plumbing and conduit parts and tent pole springs from Home Depot. There’s a 3D-printable version, too, which is useful for those around the world that can’t get access to American standard gear easily. Anyone from the Nerf scene will understand this frustration well.

The real cool part of the modular rig, though, are the tube fixtures. There’s a ball design too, but they don’t look quite as future-cool as the tubes. They use fluorescent tube protectors as a cheap source of clear tubes, and use plumbing and conduit parts to make easy-insert connectors for pairing with the modular bases. Light is courtesy of old-school non-addressable RGB LED strips, attached to flat aluminium trim with their own adhesive combined with a wrap of clear packing tape as well. The LED strip is attached to one side of the tube, with parchment paper layered inside the tubes to act as a diffuser.

Building in quantities of 8 or more, [Super Valid Designs] reckons that the tubes can be built for $50 each or less. Of course, that adds up to a few hundred dollars in total, but the results speak for themselves.

If you’re thinking of tackling this project, but DMX is beyond your current skillset, fear not. We’ve got just the primer to get you started! Video after the break.

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Hackaday Links: December 24, 2023

December 24, 2023 by 10 Comments

Back near the beginning of the current Solar Cycle 25, we penned an article on what the whole deal is with solar cycles, and what could potentially lie in store for us as the eleven-year cycle of sunspot population developed. Although it doesn’t really come across in the article, we remember being somewhat pessimistic about things, thinking that Solar Cycle 25 would be somewhat of a bust in terms of increased solar activity, given that the new cycle was occurring along with other, longer-period cycles that tend to decrease solar output. Well, looks like we couldn’t have gotten that more wrong if we tried, since the Sun lashed out with a class X solar flare last week that really lit things up. The outburst came from a specific sunspot, number 3514, and clocked in at X2.8, the most powerful flare since just before the end of the previous solar cycle. To put that into perspective, X-class flares have a peak X-ray flux of 10-4 watts/m², which when you think about it is a lot of energy. The flare resulted in a strong radio blackout; pretty much everything below 30 MHz was unusable for a while.

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