A square PCB with a Raspberry Pi Pico mounted in the middle

Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer

May 3, 2022 by Robin Kearey 37 Comments

If you’re a radiation enthusiast, chances are you’ve got a Geiger counter lying around somewhere. While Geiger counters are useful to detect the amount of radiation present, and with a few tricks can also distinguish between the three types of radiation (alpha, beta and gamma), they are of limited use in identifying radioactive materials. For that you need a different instrument called a gamma-ray spectrometer.

Spectrometers are usually expensive and complex instruments aimed at radiation professionals. But it doesn’t have to be that way: physics enthusiast [NuclearPhoenix] has designed a hand-held gamma spectrometer that’s easy to assemble and should fit in a hobbyist budget. It outputs spectral plots that you can compare with reference data to identify specific elements.

A PCB with a sensor wrapped in black tape — The scintillator and sensor are wrapped in black tape to block out ambient light.

The heart of the device is a scintillation crystal such as thallium-doped sodium iodide which converts incoming gamma rays into visible light. The resulting flashes are detected by a silicon photomultiplier whose output is amplified and processed before being digitized by a Raspberry Pi Pico’s ADC. The Pico calculates the pulses’ spectrum and generates a plot that can be stored on its on-board flash or downloaded to a computer.

[NuclearPhoenix] wrote a convenient program to help analyze the output data and made all design files open-source. The hardest part to find will be the scintillation crystal, but they do pop up on auction sites like eBay now and then. We’ve featured an Arduino-based gamma spectrometer before; if you’ve always wanted to roll your own scintillators, you can do that too. Continue reading “Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer” →

For Once, The Long Arm Of John Deere Presses The Right Button

May 2, 2022 by Jenny List 84 Comments

Over many years now we’ve covered right-to-repair stories, and among them has been a constant bête noire. The American farm machinery manufacturer John Deere whose instantly recognisable green and yellow tractors have reliably tilled the soil for over a century, have become the poster child for inappropriate use of DRM. It’s enough to make any farmer see red, but there’s a story from CNN which shows another side to manufacturer control. A Deere dealership in Melitopol, Ukraine, was looted by invading Russian forces, who took away an estimated $5m worth of farm machinery. The perfect crime perhaps, save for the Deere computer system being used to remotely disable them leaving the crooks with combine harvesters they can’t even start.

It makes for a good news story showing the Ukranians getting one over on the looters, and since on-farm thefts are a hot topic anywhere in the world it’s not entirely unexpected that Deere would have incorporated a kill-switch in their products. Recently we covered a look at how the relationship between motor vehicle owner and manufacturer is changing from one of product ownership to software licence, and this is evidently an example of the same thing in the world of machinery. It’s reported that the looters are seeking the help of tractor hackers, which may be unfortunate for them since the world’s go-to source for hacked Deere software is Ukraine. Perhaps they would be better remembering that Russia has legendary tractors of its own.

Thanks [Robert Piston] for the tip.

DIY Metal Detector Gives You The Mettle To Find Some Medals

May 2, 2022 by Bryan Cockfield 23 Comments

Hurricane season is rapidly approaching those of us who live in the northern hemisphere. While that does come with a good deal of stress for any homeowners who live in the potential paths of storms it also comes with some opportunities for treasure hunting. Storms tend to wash up all kinds of things from the sea, and if you are equipped with this DIY metal detector you could be unearthing all kinds of interesting tchotchkes from the depths this year.

The metal detector comes to us from [mircemk] who is known for building simple yet effective metal detectors. Unlike his previous builds, this one uses only a single integrated circuit, the TL804 operational amplifier. It also works on the principle of beat-balance which is an amalgamation of two unique methods of detecting metal. When the wire coils detect a piece of metal in the ground, the information is fed to an earpiece through an audio jack which rounds out this straightforward build.

[mircemk] reports that this metal detector can detect small objects like coins up to 15 cm deep, and larger metal objects up to 50 cm. Of course, to build this you will also need the support components, wire, and time to tune the circuit. All things considered, though it’s a great entryway into the hobby.

Want to learn more about metal detecting? Check out this similar-looking build which works on the induction balance principle.

Continue reading “DIY Metal Detector Gives You The Mettle To Find Some Medals” →

This Week In Security: Android And Linux, VirusTotal, More Psychic Signatures

April 29, 2022 by Jonathan Bennett 10 Comments

To start our week of vulnerabilities in everything, there’s a potentially big vulnerability in Android handsets, but it’s Apple’s fault. OK, maybe that’s a little harsh — Apple released the code to their Apple Lossless Audio Codec (ALAC) back in 2011 under the Apache License. This code was picked up and shipped as part of the driver stack for multiple devices by various vendors, including Qualcomm and MediaTek. The problem is that the Apple code was terrible, one researcher calling it a “walking colander” of security problems.

Apple has fixed their code internally over the years, but never pushed those updates to the public code-base. It’s a fire-and-forget source release, and that can cause problems like this. The fact that ALAC was released under a permissive license may contribute to the problem. Someone (in addition to Apple) likely found and fixed the security problems, but the permissive license doesn’t require sharing those fixes with a broader community. It’s worth pondering whether a Copyleft license like the GPL would have gotten a fix distributed years ago.

Regardless, CVE-2021-0674 and CVE-2021-0675 were fixed in both Qualcomm and MediaTek’s December 2021 security updates. These vulnerabilities are triggered by malicious audio files, and can result in RCE. An app could use this trick to escape the sandbox and escalate privileges. This sort of flaw has been used by actors like the NSO group to compromise devices via messaging apps. Continue reading “This Week In Security: Android And Linux, VirusTotal, More Psychic Signatures” →

CAD Sketcher, It’s Parametric CAD For Blender

April 27, 2022 by Anne Ogborn 39 Comments

It’s very early days for CAD Sketcher, a new parametric CAD add-on for Blender by [hlorus], but it looks very promising.

We do a lot of 3D work and like Blender as an environment. It’s always annoying that Blender doesn’t do parametric modeling, so we’re forced into a dedicated CAD package. Blending the two for that robot ocelot is always particularly annoying.

CAD Sketcher lets the user make a ‘sketch’, a 2D drawing. They then constrain it, saying “this line is vertical, that line is parallel to this one”, until the sketch is fully defined. It’s a normal part of parametric modelling. This is powerful when your model needs refined over and over.

There’s an old adage, “Better a tool that does 90% of the job well than one that does 100% poorly”. For CAD systems, (and much other software), we’d suggest “Better a tool that does 90% of the job well and works with whatever does the other 10%”.

3D render of gaurd — Guard Drawn In CAD Sketcher And Blender

We tried a test part, and being in Blender’s universe showed its value. CAD Sketcher doesn’t do bevels and rounds yet, and probably won’t for a while. But Blender’s perfectly happy doing them.

It’s not going to put SolidWorks out of business any time soon, but it’s a very promising new development. We hope it gathers some community and encourage contributions.

We cover CAD frequently, like the recent advances with CadQuery and the port of OpenSCAD to WASM.

[thanks paulvdh]

Continue reading “CAD Sketcher, It’s Parametric CAD For Blender” →

NASA’s Giant SLS Rocket Rolled Back For Repairs

April 27, 2022 by Tom Nardi 33 Comments

There’s little debate that the most exciting move in a rocket’s repertoire is when it launches itself skywards on a column of flame. But failing that, it’s still pretty interesting to see how these massive vehicles get juggled around down here on terra firma before getting fired off into the black. Which is great for anyone interested in NASA’s towering Space Launch System (SLS), as it’s been doing an awful lot of milling about on the ground for a vehicle designed to return humanity to the Moon.

Most recently, the SLS completed a trek from the iconic Vehicle Assembly Building (VAB) to launch pad 39B and back again aboard the same “crawler” that moved the Space Shuttle and Saturn V before it. While the nearly 60-year-old tracked vehicle has received some updates to carry the 98 meter (322 ft) tall booster, clearly the space agency subscribes to the “if it ain’t broke, don’t fix it” school of thought.

The SLS itself however is definitely in need of some work. The rocket was brought out to the pad for the first time on March 18th, where it was to conduct what’s known as a “wet dress rehearsal” — a test of the pre-flight operations, propellant loading, and countdown that includes everything except engine ignition. Unfortunately, the test was plagued with technical issues, and after three attempts, it was decided to bring the rocket back into the VAB to make the necessary repairs to both it and the ground support equipment.

One issue involves a valve in the Interim Cryogenic Propulsion Stage (ICPS), a propulsion module that’s being used on the early SLS flights to provide the trans-lunar injection (TLI) burn that will send the Orion spacecraft on a course towards the Moon. As the name implies, the ICPS is destined to be replaced with the larger Exploration Upper Stage on later missions. There’s also a leak on the launch tower itself that will need to be addressed. After the identified problems are repaired and some adjustments are made, the SLS will once again be rolled out to the pad to reattempt the launch rehearsal.

Now in development for over a decade, the Space Launch System has been plagued with technical issues and delays. At the same time, commercial launch providers like SpaceX have moved the state of the art forward considerably, leading many to wonder if the mind-bogglingly expensive rocket will be able to compete with in-development vehicles such as Starship and New Glenn. The fact that missions which were previously assigned to the SLS have started to get shifted over to commercial rockets would seem to indicate that even NASA is losing confidence in their flagship program.

Fort Knutz – Squirrels Go All Mission Impossible

April 26, 2022 by Anne Ogborn 22 Comments

[Mark Rober] has a bird feeder in his back yard. Also, squirrels who eat the seed. So, as one does, he built a nine part squirrel obstacle course with a reward of walnuts at the end, and filmed them beating the course.

(Spoiler – this is all much better in the video, which we’ve placed below the break).

His four backyard squirrels enter a ‘Casino’ and avoid the plushie ‘security’. From there it’s across a rod mounted on bearings, leap into a crate under a helicopter, which zip-lines to a brick wall with randomly moving bricks, and into their hideout.

A squirrel at a model buffet in a casino — Security is about to get him.

The hideout elevator shaft leads to a sewer, which leads to the famous room from Mission Impossible where [Tom Cruise] has to avoid the floor, but to get to the hatch in the top they have to lower a ladder by ‘hacking into’ the control system (by pushing a keyboard shaped button) and lowering a rope ladder.

Next they go through a tube maze to a room full of laser beams (3D printer filament) and finally they can jump onto the platform with Fort Knutz. If they get the vault door open, they’re rewarded with a shower of walnuts.

Continue reading “Fort Knutz – Squirrels Go All Mission Impossible” →