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!

Access The Information Superhighway With A Mac Plus

October 17, 2024 by 5 Comments

For some time now, Apple has developed a reputation for manufacturing computers and phones that are not particularly repairable or upgradable. While this reputation is somewhat deserved, especially in recent years, it seems less true for their older machines. With the second and perhaps most influential computer, the Apple II, being so upgradable that the machine had a production run of nearly two decades. Similarly, the Macintosh Plus of 1986 was surprisingly upgradable and repairable and [Hunter] demonstrates its capabilities by bringing one onto the modern Internet, albeit with a few tricks to adapt the old hardware and software to the modern era.

The Mac Plus was salvaged from a thrift store, and the first issue to solve was that it had some rotten capacitors that had to be replaced before the computer could be reliably powered on at all. [Hunter] then got to work bringing this computer online, with the only major hardware modification being a BlueSCSI hard drive emulator which allows using an SD card instead of an original hard disk. It can also emulate an original Macintosh Ethernet card, allowing it to fairly easily get online.

The original operating system and browser don’t support modern protocols such as HTTPS or scripting languages like Javascript or CSS, so a tool called MacProxy was used to bridge this gap. It serves simplified HTML from the Internet to the Mac Plus, but [Hunter] wanted it to work even better, adding modular domain-specific handling to allow the computer to more easily access sites like Reddit, YouTube, and even Hackaday, although he does call us out a bit for not maintaining our retro page perhaps as well as it ought to be.

[Hunter] has also built an extension to use the Wayback Machine to serve websites to the Mac from a specific date in the past, which really enhances the retro feel of using a computer like this to access the Internet. Of course, if you don’t have original Macintosh hardware but still want to have the same experience of the early Internet or retro hardware this replica Mac will get you there too.

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Ubiquitous Successful Bus: Version 2

October 17, 2024 by 52 Comments

I’ve talked a fair bit about USB-C before, explaining how it all works, from many different angles. That said, USB-C is just the physical connector standard, plus the PD part that takes care of voltages and altmodes – things like data transfer are still delegated to the two interfaces you invariably end up using on USB-C ports, USB 2, and USB 3.

You might think USB 2 and USB 3 are tightly related, but in many crucial ways, they couldn’t be more different. I have experience working with both, and, as you might guess, I want to share it all with you. You might be surprised to hear there’s plenty to learn about USB 2 in particular – after all, we’ve had it hang around for 30 years now. Well, let’s make sure you’re fully caught up!

The Ingredients

USB 2 is a point-to-point link – one side is “host” and another is “device”, with the host typically being a PC chipset or a single-board computer. USB 2 relies on a single pseudodifferential pair. It’s “pseudodifferential” because the wires don’t just do differential signaling – they also use digital logic levels and pullup/pulldown resistors to signal device presence, especially in the beginning when the USB link is still getting established. Indeed, you can imitate a USB device’s presence with just a resistor.
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The FNIRSI HRM-10 Internal Resistance Meter

October 17, 2024 by 16 Comments

Occasionally, we find fun new electronic instruments in the wild and can’t resist sharing them with our readers. The item in question is the FNIRSI HRM-10 Internal resistance meter, which we show here being reviewed by [JohnAudioTech].

So what does it do, and why would you want one? The device is designed to measure batteries so you can quickly determine their health. Its operating principle also allows it to do a decent job of measuring low-resistance parts, which is not necessarily as easy to achieve with the garden variety multimeter, especially the low-end ones. We reckon it would be useful in the field for checking the resistance of switches and relays, possibly in automotive or industrial applications. The four-pin connector is needed because there are two wires per probe, making a Kelvin (also known as four-wire) connection.

Likely, the operating principle is to apply a varying load to the battery under test and then measure the voltage drop. The slope of the voltage sag vs load is a reasonable estimate of the resistance of the source, at least for the applied voltage range. The Kelvin connection uses one pair of wires to apply the test current from a relatively low-impedance source and the second pair to measure the voltage with a high input impedance. That way, the resistance of the probe wires can be calibrated out, giving a much more accurate measurement. Many lab-grade measurement equipment works this way.

Circling back to the HRM-10, [John] notes that it also supports limit testing, making it a helpful gauging tool for the workbench when sorting through many batteries. Data logging and the ability to upload to a computer completes the feature set, which is quite typical for this level of product now. Gone are the days of keeping a manual logbook next to the instrument stack and writing everything down by hand!

We’ve touched on measuring battery internal resistance before, but it was a while ago. Regarding Kelvin connections, here’s a quick guide and a hack upgrading a cheap LCR to support 4-wire probes.

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Mining And Refining: Mine Dewatering

October 17, 2024 by 9 Comments

From space, the most striking feature of our Pale Blue Dot is exactly what makes it blue: all that water. About three-quarters of the globe is covered with liquid water, and our atmosphere is a thick gaseous soup laden with water vapor. Almost everywhere you look there’s water, and even where there’s no obvious surface water, chances are good that more water than you could use in a lifetime lies just below your feet, and accessing it could be as easy as an afternoon’s work with a shovel.

And therein lies the rub for those who delve into the Earth’s depths for the minerals and other resources we need to function as a society — if you dig deep enough, water is going to become a problem. The Earth’s crust holds something like 44 million cubic kilometers of largely hidden water, and it doesn’t take much to release it from the geological structures holding it back and restricting its flow. One simple mineshaft chasing a coal seam or a shaft dug in the wrong place, and suddenly all the hard-won workings are nothing but flooded holes in the ground. Add to that the enormous open-pit mines dotting the surface of the planet that resemble nothing so much as empty lakes waiting to fill back up with water if given a chance, and the scale of the problem water presents to mining operations becomes clear.

Dewatering mines is a complex engineering problem, one that intersects and overlaps multiple fields of expertise. Geotechnical engineers work alongside mining engineers, hydrogeologists, and environmental engineers to devise cost-effective ways to control the flow of water into mines, redirect it when they can, and remove it when there’s no alternative.

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What Would It Take To Recreate Bell Labs?

October 17, 2024 by 45 Comments

It’s been said that the best way to stifle creativity by researchers is to demand that they produce immediately marketable technologies and products. This is also effectively the story of Bell Labs, originally founded as Bell Telephone Laboratories, Inc. in January 1925. As an integral part of AT&T and Western Electric, it enjoyed immense funding and owing to the stable financial situation of AT&T very little pressure to produce results. This led to the development of a wide range of technologies like the transistor, laser, photovoltaic cell, charge-coupled cell (CCD), Unix operating system and so on. After the break-up of AT&T, however, funding dried up and with it the discoveries that had once made Bell Labs such a famous entity. Which raises the question of what it would take to create a new Bell Labs?

As described in the article by [Brian Potter], one aspect of Bell Labs that made it so successful was that the researchers employed there could easily spend a few years tinkering on something that tickled their fancy, whether in the field of semiconductors, optics, metallurgy or something else entirely. There was some pressure to keep research focused on topics that might benefit the larger company, but that was about it, as the leadership knew that sometimes new technologies can take a few years or decades to come to fruition.

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Read All About It: The 2024 Supercon Site Is Live

October 17, 2024 by 4 Comments

With the 2024 Hackaday Supercon just a couple weeks away, we’re pleased to announce that the official site for the three-day event is now live!

On the brand-new Supercon page, you can find a listing of all of our fantastic speakers, the hands-on workshops, and perhaps most importantly, the schedule of when everything is happening. As always, Supercon is jam-packed with incredible content, so you’ll want to consult with the schedule to navigate your way through it. Don’t worry if it ends up that two talks you want to see are scheduled for the same time — we’ll be recording all of the talks and releasing them on the Hackaday YouTube channel, so you won’t miss out.

If you’re still on the fence, we do have a few tickets left at the time of this writing. All of the workshops are full at this point, but you can still get on the waiting list for a few of them just in case a spot opens up.