RF Noise Floor Concerns From Both Sides Of The Atlantic

Our feed is full of stories about the RF noise floor today, and with good reason. The ARRL reports on the International Amateur Radio Union Region 1 president, [Don Beattie, G3BJ] warning that in densely populated parts of Europe there is a danger that parts of the RF spectrum have become so swamped with noise as to be rendered unusable, while on the other side of the Atlantic we have RadioWorld reporting on similar problems facing AM broadcasting in the USA.

At issue are the usual suspects, interference from poorly shielded or suppressed domestic electronic devices, VDSL broadband, power-over-Ethernet, solar and wind power systems, and a host of other RF-spewing electronics. The combined emissions from all these sources have raised the noise level at some frequencies to the point at which it conceals all but the strongest signals. Any radio amateur will tell you that a station in a rural location will be electrically much quieter than one in a city, it seems that this effect has now reached a crescendo.

In the RadioWorld article, the author [Tom F. King] and his collaborator [Jack Sellmeyer] detail a series of tests they performed on a selection of lighting products from a quality brand, bought at a local Home Depot store. They were gathering data for a submission to the FCC enquiry on the noise floor issue we reported on last year. What they found was unsurprising, significant emissions from all the products they tested. They make some stiff recommendations to the FCC and other bodies concerned with radio spectrum to get tough with offending devices, to stay on top of future developments, and for operators of AM stations to pursue sources of interference.

It could be that there is so much equipment contributing to the noise floor that this battle is lost, but it doesn’t have to be this way. Anyone who has had to prepare a product to pass a properly carried out EMC test will tell you that the requirements are stringent, and it is thus obvious that many manufacturers are shipping products unworthy of the certification they display. It is to be hoped that the authorities will begin to take it seriously before it becomes an order of magnitude worse.

Compliance label image, Moppet65535 [CC BY-SA 3.0].

The Cheapest Meter on Banggood

According to [pileofstuff], he didn’t really need another digital multimeter. However, when he saw a DT-832 meter on Banggood for the princely sum for $4.99 he wondered just what kind of meter you’d get for that price. You can see his conclusions in his recent video (below). He does make it clear, by the way, that he wasn’t paid for the review or given the meter. He just decided to see what $5 would buy in a meter.

Depending on your predisposition to cheap Asian electronics, you may or may not be surprised. After all, for $5 you can’t expect a top-of-the-line lab instrument. The device measures AC and DC voltage, DC amperage, ohms, transistor beta, and has a diode tester and continuity buzzer. It also has some frequency measurement capability. You can’t be too surprised it doesn’t auto range, though. To be fair, although he mentions Banggood as the source of the meter, a quick Google search shows you can get them from all the usual sources, and the price is down to $3.73 as long as you let them ship it from Canada.

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Radiohead’s Greatest Hits for the ZX Spectrum

We’ll admit that only a few of us here at Hackaday are Radiohead fans. However, we all couldn’t help but appreciate their new remastered release of OK Computer. The new release contains some bonus material. At the end of the bonus material is a strange noise that turns out to be a ZX Spectrum Basic program.[OooSLAJEREKooO] managed to find it, play it, and record it for all of us (see video below).

The two minutes of tones might sound unfamiliar to a modern computer user, but back in the day, audio tones were used to communicate over phone lines and to load and save programs via cassette tape recorders. You might be asking yourself: why the ZX Spectrum? Radiohead is from the UK, but that’s not the complete picture. Of all home computers, the ZX Spectrum had a higher effective bit rate when storing data on tape. Basically, it takes less time (and less tape) to put it on a Speccy than a C64 or Apple.

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Hey NASA, Do You Want Your Stuff Back?

What would you do if you found hidden away artifacts of aerospace technology from the Apollo era?

You call NASA.

Two hulking computers — likely necessitating the use of a crane to move them — and hundreds of tape reels were discovered in the basement of a former IBM engineer by their heir and a scrap dealer cleaning out the deceased’s home. Labels are scarce, and those that are marked are mostly from the late 1960s through the mid 1970s, including data from the Pioneer 8 to 11 missions, as well as the Helios missions.

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STM32CubeMX Makes Makefiles

When hardware manufacturers make GUI code-generation tools, the resulting files often look like a canned-spaghetti truck overturned on the highway — there’s metaphorical overcooked noodles and red sauce all over the place. Sometimes we think they’re doing this willfully to tie you into their IDE. Not so the newest version of ST’s graphical STM32CubeMX, which guides you through a pleasant pin-allocation procedure and then dumps out, as of the latest version, a clean Makefile.

Yes, that’s right. This is a manufacturer software suite that outputs something you can actually use with whatever editor, GUI, compiler, or environment that you wish — even the command line. Before this release, you had to go through a hacky but functional script to get a Makefile out of the CubeMX. Now there’s official support for real hackers. Thanks, ST!

If you’re compiling on your own, you’ll need to update the BINPATH variable to point to your compiler. (We use the excellent GNU ARM Embedded Toolchain ourselves, which is super-easy to install on almost any Linux.) If you want to use STM32CubeMX with the Eclipse IDE, [kali prasad yadav] sent us PDF instructions — it’s not hard.

If you doubt that the availability of a free, open, and non-constraining toolchain can matter for a silicon vendor, we’d point to AVR and the Arduino platform that spun off of their support of GCC. Sure, Atmel still pushes their all-in-one wonder, Atmel Studio, which is better than the Arduino IDE by most any metric. But Studio is closed, and Arduino is open. We’d love to see the number of Studio users compared with Arduino users.

Congratulations to ST for taking a big step in the right, open-toolchain, direction.

ESP to Wireshark

Everyone’s favorite packet sniffing tool, Wireshark, has been around for almost two decades now. It’s one of the most popular network analysis tools available, partially due to it being free and open source. Its popularity guaranteed that it would eventually be paired with the ESP32/8266, the rising star of the wireless hardware world, and [spacehuhn] has finally brought these two tools together to sniff WiFi packets.

The library that [spacehuhn] created uses the ESP chip to save Pcap files (the default Wireshark filetype) onto an SD card or send the data over a serial connection. The program runs once every 30 seconds, creating a new Pcap file each time. There are many example scripts for the various hardware you might be using, and since this is written for the ESP platform it’s also Arduino compatible. [spacehuhn] has written this as a proof-of-concept, so there are some rough edges still, but this looks very promising as a network analysis tool.

[spacehuhn] is no stranger to wireless networks, either. His YouTube channel is full of interesting videos of him exploring various exploits and testing other pieces of hardware. He’s also been featured here before for using an ESP8266 as a WiFi jammer.

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London Gatwick Airport Closes Runway In Alleged Drone Strike

London is one of those cities with an identity problem when it comes to airports. There is no one London airport, instead a group of airports serve the city at various distances from it. London Gatwick is the second largest of these, and sits with its single runway in the Sussex countryside about 30 miles south of the city.

If you follow British news sources, you may have heard a little about Gatwick in the last couple of days. Its runway was closed for two short periods and a selection of flights were diverted, because of what is being reported as a drone sighting. This is an extremely serious matter, responsible multirotor owners will be painfully aware of the distance and altitude regulations surrounding flights near airports.

An oft-shared drone identification guide for airline pilots, of uncertain provenance.
An oft-shared drone identification guide for airline pilots, of uncertain provenance (phantompilots.com).

If you are familiar with the way that drone stories are reported by the mass media, you will probably not need to click on the link above to the BBC reporting to find out its tone. There is significant concern within the multirotor community that it presents a very one-sided view, and takes at face value the assertion that the sighting was a drone, when in fact there is no proof at all of that being the case. For those of us who have seen many such stories come and go it is difficult not to agree with the drone pilots, there is at best some lazy reporting in the air, and at worst some outright journalistic irresponsibility.

As Hackaday readers, you are used to writers with an in-depth knowledge of the subjects upon which they write. We don’t know all possible facets of technology and we occasionally get things wrong, but we all have very strong backgrounds in the tech, hacker, and maker industries and communities we write about. We have engineering education, we’ve worked in a wide variety of technology industries, we build our own stuff for fun, and we’ve founded and run hackspaces.

By comparison the journalists whose work you will read in the mainstream media are generalists. They will have a specific educational background and a particular set of interests, but in their work they cover whatever stories tumble off the endless conveyor belt of events. Thus when a drone story appears, they find themselves out of their normal comfort zone of politics or local news, and can not rely on their experience to inform their coverage of it. The responsible journalistic approach is to do a little research and ask the pertinent questions asking for concrete proof of drone involvement. We’re still waiting for that to happen in these allege drone encounters.

Multirotor building and flying is a significant feature of our community, and anything that brings the attention of law enforcement to the kind of work we do should be a worry to us all. Multirotors are not the only things covered by Hackaday that could be misrepresented in the same way. We’ve visited this topic before, take a look at our analysis of a series of air proximity reports blamed on drones. Some of them, you couldn’t make up.

Gatwick airport image: Andre Wadman [GFDL 1.2].