Hackaday Links: February 23, 2020

February 23, 2020 by Dan Maloney 19 Comments

If you think your data rates suck, take pity on New Horizons. The space probe, which gave us lovely pictures of the hapless one-time planet Pluto after its 2015 flyby, continued to plunge and explore other, smaller objects in the Kuiper belt. In January of 2019, New Horizons zipped by Kuiper belt object Arrokoth and buffered its findings on the spacecraft’s solid-state data recorders. The probe has been dribbling data back to Earth ever since at the rate of 1 to 2 kilobits per second, and now we have enough of that data to piece together a story of how planets may have formed in the early solar system. The planetary science is fascinating, but for our money, getting a probe to narrowly miss a 35-kilometer long object at a range of 6.5 billion km all while traveling at 51,500 km/h is pretty impressive. And if as expected it takes until September to retrieve all the data from the event at a speed worse than dialup rates, it’ll be worth the wait.

Speaking of space, if you’re at all interested in big data, you might want to consider putting your skills to work in the search for extraterrestrial intelligence. The Berkeley SETI Research Center has been feeding data from the Green Bank Telescope and their Automated Planet Finder into the public archive of Breakthrough Listen, a 10-year, $100 million initiative to scan the million closest stars in our galaxy as well as the 100 nearest galaxies for signs of intelligent life. They’re asking for help to analyze the torrents of data they’re accumulating, specifically by developing software and algorithms to process the data. They’ve set up a site to walk you through the basics and get you started. If you’re handy with Python and have an interest in astronomy, you should check it out.

Staying with the space theme, what’s the best way to get kids interested in space and electronics? Why, by launching a satellite designed to meme its way across the heavens, of course. The Mission for Education and Multimedia Engagement satellite, or MEMESat-1, is being planned for a February 2021 launch. The 1U cubesat will serve as an amateur radio repeater and slow-scan TV (SSTV) beacon that will beam down memes donated to the project and stored on radiation-hardened flash storage. In all seriousness, this seems like a great way to engage the generation that elevated the meme to a modern art form in a STEM project they might otherwise show little interest in.

It looks as though Linux might be getting a big boost as the government of South Korea announced that they’re switching 3.3 million PCs from Windows to Linux. It’s tempting to blame Microsoft’s recent dropping of Windows 7 support for the defenestration, but this sounds like a plan that’s been in the works for a while. No official word on which distro will be selected for the 780 billion won ($655 million) effort, which is said to be driven by ballooning software license costs and a desire to get out from under Microsoft’s thumb.

And finally, in perhaps the ickiest auction ever held, the “Davos Collection” headed to the auction block this week in New York. The items offered were all collected from the 2018 World Economic Forum in Davos, Switzerland, where the world’s elites gather to determine the fate of the 99.999%. Every item in the collection, ranging from utensils and glassware used at the many lavish meals to “sanitary items” disposed of by the billionaires, and even hair and fluid samples swabbed from restrooms, potentially holds a genetic treasure trove in the form of the DNA it takes to be in the elite. Or at least that’s the theory. There’s a whole “Boys from Brazil” vibe here that we find disquieting, and we flatly refuse to see how an auction where a used paper cup is offered for $8,000 went, but if you’d like to virtually browse through the ostensibly valuable trash of oligarchs, check out the auction catalog.

Simple, Self-Contained LoRa Repeater In About An Hour

May 2, 2019 by Donald Papp 5 Comments

[Dave Akerman]’s interest in high-altitude projects means he is no stranger to long-range wireless communications, for which LoRa is amazingly useful. LoRa is a method of transmitting at relatively low data rates with low power over long distances.

Despite LoRa’s long range, sometimes the transmissions of a device (like a balloon’s landed payload) cannot be received directly because it is too far away, or hidden behind buildings and geography. In these cases a useful solution is [Dave]’s self-contained LoRa repeater. The repeater hardware is simple, and [Dave] says that if one has the parts on hand, it can be built in about an hour.

The device simply re-transmits any telemetry packets it receives, and all that takes is an Arduino Mini Pro and a small LoRa module. A tiny DC-DC converter, battery, and battery charger rounds out the bill of materials to create a small and self-contained unit that can be raised up on a mast, flown on a kite, or carried by a drone.

The repeater’s frequency and other settings can even be reprogrammed (using a small windows program) for maximum flexibility, making the little device invaluable when going hunting for landed payloads like the one [Dave] used to re-create a famous NASA image using a plastic model and a high-altitude balloon. Check out the details on the GitHub repository for the project and start mashing “add to cart” for parts at your favorite reseller.

The $50 Ham: Checking Out The Local Repeater Scene

April 11, 2019 by Dan Maloney 24 Comments

So far in this series, we’ve covered the absolute basics of getting on the air as a radio amateur – getting licensed, and getting a transceiver. Both have been very low-cost exercises, at least in terms of wallet impact. Passing the test is only a matter of spending the time to study and perhaps shelling out a nominal fee, and a handy-talkie transceiver for the 2-meter and 70-centimeter ham bands can be had for well under $50. If you’re playing along at home, you haven’t really invested much yet.

The total won’t go up much this week, if at all. This time we’re going to talk about what to actually do with your new privileges. The first step for most Technician-class amateur radio operators is checking out the local repeaters, most of which are set up exactly for the bands that Techs have access to. We’ll cover what exactly repeaters are, what they’re used for, and how to go about keying up for the first time to talk to your fellow hams.

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Es’hail-2: Hams Get Their First Geosynchronous Repeater

March 18, 2019 by Dan Maloney 27 Comments

In the radio business, getting the high ground is key to covering as much territory from as few installations as possible. Anything that has a high profile, from a big municipal water tank to a roadside billboard to a remote hilltop, will likely be bristling with antennas, and different services compete for the best spots to locate their antennas. Amateur radio clubs will be there too, looking for space to locate their repeaters, which allow hams to use low-power mobile and handheld radios to make contact over a vastly greater range than they could otherwise.

Now some hams have claimed the highest of high ground for their repeater: space. For the first time, an amateur radio repeater has gone to space aboard a geosynchronous satellite, giving hams the ability to link up over a third of the globe. It’s a huge development, and while it takes some effort to use this new space-based radio, it’s a game changer in the amateur radio community.

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The WiFi Repeater You Probably Have On Your Bench

December 25, 2017 by Al Williams 29 Comments

Few things are as frustrating as a WiFi signal that drops in and out. On a public network it is bad enough but at home? Even if you can live with it, your cohabitants will certainly impune your technical abilities if they don’t have solid WiFi. One solution is a WiFi repeater. You can buy one, of course. But you can also make one out of an ESP8266 and some code from GitHub. There is also a video about the project, below.

[Martin Ger’s] code implements NAT, so it isn’t a true WiFi repeater, but more of a bridge or router. Of course, that means performance isn’t stellar, but tests show it can sustain about 5 Mbps, which isn’t bad for a little board that costs a couple of bucks. There is a limit of 8 clients, but that’s more than enough for a lot of cases. Even if you don’t want to use it as a router, it has a mesh mode that could be a basis for some interesting projects all by itself.

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In-Band Signaling: Coded Squelch Systems

September 13, 2017 by Dan Maloney 18 Comments

In the first part of our series on in-band signaling, we discussed one of the most common and easily recognizable forms of audio control, familiar to anyone who has dialed a phone in the last fifty years – dual-tone multifrequency (DTMF) dialing. Our second installment will look at an in-band signaling method that far fewer people have heard, precisely because it was designed to be sub-audible — coded squelch systems for public service and other radio services. Continue reading “In-Band Signaling: Coded Squelch Systems” →

My Beef With Ham Radio

December 12, 2016 by Dan Maloney 371 Comments

My amateur radio journey began back in the mid-1970s. I was about 12 at the time, with an interest in electronics that baffled my parents. With little to guide me and fear for my life as I routinely explored the innards of the TVs and radios in the house, they turned to the kindly older gentleman across the street from us, Mr. Brown. He had the traditional calling card of the suburban ham — a gigantic beam antenna on a 60′ mast in the backyard – so they figured he could act as a mentor to me.

Mr. Brown taught me a lot about electronics, and very nearly got me far enough along to take the test for my Novice class license. But I lost interest, probably because I was an adolescent male and didn’t figure a ham ticket would improve my chances with the young ladies. My ham ambitions remained well below the surface as life happened over the next 40 or so years. But as my circumstances changed, the idea of working the airwaves resurfaced, and in 2015 I finally took the plunge and earned my General class license.

The next part of my ham story is all-too-familiar these days: I haven’t done a damn thing with my license. Oh, sure, I bought a couple of Baofeng and Wouxun handy-talkies and lurked on the local repeaters. I even bought a good, solid HF rig and built some antennas, but I’ve made a grand total of one QSO — a brief chat with a ham in Texas from my old home in Connecticut on the 10-meter band. That’s it.

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