A black PCB with an ESP32 and an SBM-20 geiger counter

Flexible Radiation Monitoring System Speaks LoRa And WiFi

Radioactivity has always been a fascinating phenomenon for anyone interested in physics, and as a result we’ve featured many radioactivity-related projects on these pages over the years. More recently however, fears of nuclear disaster have prompted many hackers to look into environmental radiation monitoring. [Malte] was one of those looking to upgrade the radiation monitor on his weather station, but found the options for wireless geiger counters a bit limited.

So he decided to build himself his own Wifi and LoRa compatible environmental radiation monitor. Like most such projects it’s based on the ubiquitous Soviet-made SBM-20 GM tube, although the design also supports the Chinese J305βγ model. In either case, the tube’s operating voltage is generated by a discrete-transistor based oscillator which boosts the board’s 5 V supply to around 400 V with the help of an inductor and a voltage multiplier.

Graphs showing temperature, humidity and radiation levels
Data can be visualized in graphs, together with other data from the weather station like temperature and humidity

The tube’s output signal is converted into clean digital pulses to be counted by either an ESP32 or a Moteino R6, depending on the choice of wireless protocol. The ESP can make its data available through a web interface using its WiFi interface, while the Moteino can communicate through LoRa and sends out its data using MQTT. The resulting data is a counts-per-minute value which can be converted into an equivalent dose in Sievert using a simple conversion formula.

All design files are available on [Malte]’s website, including a PCB layout that neatly fits inside standard waterproof enclosures. Getting more radiation monitors out in the field can only be a good thing, as we found out when we tried to detect a radiation accident using community-sourced data back in 2019. Don’t like WiFi or LoRa? There’s plenty of other ways to connect your GM tubes to the internet.

Understanding Wavelets

Mathematical transforms can be a great help in understanding signals. Imaging trying to look at a complex waveform and figuring out the frequency components without the Fourier transform. [Artem Kirsanov] calls the wavelet transform a “mathematical microscope” and his video gives you a great introduction to the topic. You can see the video below.

The video starts with a discussion about how the time domain and frequency domain have a dual relationship — not big news if you’ve dealt with Fourier transforms and — in fact — that’s the next topic in the video. However, there are limitations to the transformation — you lose time domain information in the process.

Continue reading “Understanding Wavelets”

London Bridge Has Fallen — By Radio

One of the global news stories this week has been the passing of the British monarch, Queen Elizabeth II. Since she had recently celebrated 70 years on the throne, the changing of a monarch is not something that the majority of those alive in 2022 will have seen. But it’s well known that there are a whole suite of “London Bridge has fallen” protocols in place for that eventuality which the various arms of the British government would have put in motion immediately upon news from Balmoral Castle. When it became obvious that the Queen’s health was declining, [Hackerfantastic] took to the airwaves to spot any radio signature of these plans. [Update 2022-09-11] See the comments below and a fresh Tweet to clarify, it appears these were not the signals they were at first suspected to be.

What he found in a waterfall view of the 4 MHz military band was an unusual transmission, a set of strong QPSK packets that started around 13:40pm on the 8th of September, and continued on for 12 hours before disappearing.  The interesting thing about these transmissions is not that they were a special system for announcing the death of a monarch, but that they present a rare chance to see one of the country’s Cold War era military alert systems in action.

It’s likely that overseas embassies and naval ships would have been the intended recipients and the contents would have been official orders to enact those protocols, though we’d be curious to know whether 2022-era Internet and broadcast media had tipped them off beforehand that something was about to happen. It serves as a reminder: next time world news stories happen in your part of the world, look at the airwaves!

The Open Source Rotary Cell Phone, Two Years Later

We know the pandemic has screwed with a lot of people’s sense of time, but we doubled checked, and it has indeed been more than two years since the Internet first laid eyes upon the incredible rotary cell phone put together by [Justine Haupt]. We’re happy to report that not only has she continued to develop and improve the phone since the last time it made the rounds, but that the kits for this open source marvel are currently available for preorder.

A lot has happened since this phone last graced the pages of Hackaday. For one thing, it’s now officially known as the Rotary Un-Smartphone. [Justine] has also spun up a small company for the express purposes of putting these kits into production, which clearly speaks to just how much attention the project picked up in mainstream circles.

The new rotary mechanism is based on modern components.

In terms of hardware, while the phone might look more or less the same externally, [Justine] says that there’s not a single unchanged component from the previous version. The 3D printed case has given way to a beautiful injection molded enclosure offered in several retro colors, and the rather incongruous rubber ducky antenna has been replaced with an articulated aerial that serves as a kickstand.

Speaking of reception, the original 3G cellular modem has been upgraded to a LTE-compatible model from uBlox, so it should still get a signal for a decade or so before your carrier kicks it off the network. When ordering the kit you can choose between a global version using the TOBY-R200 modem, or a North American variant with the TOBY-R202.

Even the user interface has been spruced up — while the previous model featured a simple LED indicator on the front to show when you were in a call, the new version features an OLED display that will show you the currently dialed number as well as status information such as battery life and signal strength. Some may be disappointed to hear that the authentic Western Electric model 10A rotary dial has been deleted in favor of a custom designed mechanism that uses all modern components, but we can certainly understand why the change had to be made from a production standpoint.

Continue reading “The Open Source Rotary Cell Phone, Two Years Later”

2022 Cyberdeck Contest: The Folding Mini-Deck

The trend for cyberdecks has brought us many takes on the home-made portable computers, but it’s fair to say that some of them can be rather unwieldy. This is not an accusation you can point at [Smeef] with the Mini-Deck though, because its Raspberry Pi Zero, Adafruit miniature display, and tiny keyboard make the whole unit able to fit in the palm of a hand. We’re not sure we’ve seen one so compact!

The most obvious feature is the keyboard, it’s a DreamGear MiniKey miniature USB keyboard. It doesn’t have all the useful buttons a PC board has, so there’s also a separate set of buttons to cover those. Then there’s an analog stick connected to an Arduino Pro Micro that takes the functionality of a mouse, and an Adafruit Mini PiTFT 1.3″ Display. While a fully-functional display for the Pi, we do wonder if this tiny screen might actually be a bit too tiny to be practical. Power for the unit comes via an 18650 battery, which also functions as a pin for a folding mechanism.

The result is something that looks, feels, and works like a cyberdeck, but all in miniature. It might be a stretch to write a Hackaday piece on a machine like it, but we’re guessing that merely having built something like this is cool enough in itself. Certainly it’s considerably smaller than previous contenders for the smallest build.

Who Is Responsible For Your Safety?

We recently posted a video where some ingenious metal-shop hackers made a simple jig to create zig-zag oil grooves on the inside of a cylinder, and the comment section went wild. What ensued was a flood of complaints that the video displayed unsafe shop practices, from lack of safety glasses to wearing flip-flops while operating a lathe.

Where the comments went off the rails were people asking Hackaday to remove our discussion of the video, because the commenters thought that we were somehow implicitly encouraging open-toed footwear in the presence of machine tools. We certainly weren’t! We wanted you all to see the clever machining hack, and be inspired to build your own. We figure that you’ve got the safety angle covered.

Now don’t get me wrong – there were safety choices made in the video that I would not personally make. But it also wasn’t my shop and I wasn’t operating the machines. And you know who is ultimately responsible for the safety in my basement shop? Me! And guess who is responsible for safety in your shop.

But of course, none of us know everything about every possible hazard. (Heck, I wrote just that a few weeks ago!) So while we’re sympathetic with the “that’s not safe!” crew, we’re not going to censor inspiring hacks just because something done along the way wasn’t done in the way we would do it. Instead, it’s our job, in the comment section as in Real Life™, to help each other out and share our good safety tips when we can.

You’ll see some crazy stuff in videos, and none of it is to be repeated without thinking. And if you do see something dodgy, by all means point it out, and mention how you would do it better. Turn the negative example around for good, rather than calling for its removal. Use the opportunity to help, rather than hide.

But also remember that when the chips are flying toward your personal eyeballs, it’s up to you to have glasses on. We all do potentially hazardous things all the time, and it’s best to be thinking about the risks and their mitigation. So stay safe out there. Keep on learning and keep on hacking!

The Big List Of Naughty Strings Helps Find Those User Input Problems

Any software that accepts user input must take some effort to sanitize incoming data, lest unexpected and unwelcome things happen. Here to make that easier is the Big List of Naughty Strings, an evolving list of edge cases, unusual characters, script-injection fragments, and all-around nonstandard stuff aimed at QA testers, developers, and the curious. It’s a big list that has grown over the years, and every piece of it is still (technically) just a string.

These strings have a high probability of surfacing any problems with handling user input. They won’t necessarily break anything, but they may cause unexpected things to happen and help point out any issues that need fixing. After all, many attacks hinge on being able to send unexpected inputs that don’t get properly sanitized.

Finding bad inputs is not always entirely straightforward, but at least the Big List of Naughty Strings is available in a variety of formats to make it easy to use. [Max Woolf] has been maintaining the list for years, but if you haven’t heard of it yet and think it might come in useful, now’s the time to give it a look. Now you can help ensure your system can handle things like someone registering a company named ; DROP TABLE “COMPANIES”;– LTD.